Visualizzazione post con etichetta Omeopatia. Mostra tutti i post
Visualizzazione post con etichetta Omeopatia. Mostra tutti i post

giovedì 30 maggio 2013

Medicine alternative: una iattura per la sinistra (e non solo)


Riposto questo vecchio post del 2009 anche se mi farò molti nemici e farò arricciare il naso a molti amici. 

L'articolo contiene argomentazioni che oggi non ripeterei, ma in buona sostanza i concetti di fondo rimagono inalterati

di Franco Cilli

Come possano persone raziocinati credere nelle stravaganze e nelle assurdità delle cosiddette medicine alternative, è per me motivo di sorpresa ed anche di preoccupazione. Lo so, non dovrei sorprendermi, le spiegazioni ci sono, ma evidentemente il mio lobo limbico non si arrende e continua a produrre emozioni in risposta a stimoli stereotipati. Amici che conosco da una vita, medici, professionisti che lavorano col cervello, persone ragionevoli, credono che esista una “medicina alternativa”, cioè una scienza che la medicina ufficiale ripudia, oscura, mette all’angolo, ostacola scientemente per biechi motivi di profitto, censura o semplicemente ignora. Lo credono perché vogliono crederci. Per me è una sorta di dissociazione psicotica, di delirio: una parte del loro ego non è disposta ad accettare le evidenze della ragione, malgrado le infinite confutazioni che ridicolizzano le loro credenze. La cosa buffa è che ci credono per una sorta di dover essere, a scatola chiusa, senza neanche preoccuparsi di quale sia la materia del contendere, quella pratica deve essere buona. Punto. Se citi, ad esempio, il dottor Andrew Still e le sue bizzarre teorie, che hanno dato origine all’osteopatia, rimangono a bocca aperta. Andrew Still chi? Ti chiedono. Non conoscono né lui, né le sue teorie: anatomia, anatomia, e poi ancora anatomia (sembra di sentire Lenin)! La patologia che deriva da un’interruzione dell’integrità dell’organo, le manipolazioni, il movimento delle ossa craniche, hai presente? Boh! Nessuna reazione da parte dell’interlocutore fedele. Una mia carissima amica mi spiega pazientemente, con un sorriso di compatimento, che “loro”, gli osteopati, manipolano, ergo fanno qualcosa di pratico, non sono fantasie. Manipolano? E allora? Questa sarebbe una prova di efficacia? Chiunque è capace di manipolare. In base a questa logica i ceramisti ed i fornai sarebbero degli eccellenti terapeuti. Ma loro hanno studiato, e pure tanto! Studiato che?

Questo è il punto. Si può studiare qualcosa per secoli, ma ciò non significa che l’oggetto di studio sia una vera scienza, e che tale presunta scienza dia risultati concreti. Guardate la psicoanalisi. Bisogna provarlo. Non solo, ma le ipotesi di partenza, ciò che costituisce, diciamo così, la parte creativa della ricerca, devono essere anch’esse credibili: se ipotizzo che lo zinco può interferire in determinati meccanismi cellulari che portano poi allo sviluppasi del morbo di Alzheimer, faccio un’ipotesi fondata su una mole di studi precedenti che avvalorano la mia ipotesi di partenza e mi consentono di elaborare un progetto di studio e di ricerca, non dico una cosa campata per aria. Se ipotizzo invece, che un dato fiore, solo perchè assomiglia a un mio cugino grasso e un po’ allegrotto, sia in grado di risintonizzare la mia energia vitale con quella dell’universo, dico solo una patente assurdità (i fiori di Bach! Altra bella chicca).

L’idea in sé di “medicina alternativa” appare, a ben pensarci, alquanto balzana. Oggi medici cosiddetti allopatici e cosiddetti olistici, concordano sulla necessità di un superamento del concetto di “medicina alternativa”, in quanto, come è logico supporre, non esiste una “medicina alternativa”, almeno fino a quando non esisteranno “malattie alternative”. Esiste, si dice, una medicina efficace ed una non efficace, una medicina basata sulle evidenze ed una che poggia su basi poco solide. Vero, sebbene l’idea di una conoscenza alternativa, che si ponga al di fuori dei paradigmi della scienza ufficiale, permane. Questa idea ha radici lontane ed ha rappresentato in passato la necessità di tenere in vita una cultura ed una scienza, come quella tramandata attraverso lo gnosticismo prima ed il movimento delle streghe successivamente, che proclamavano una visione alternativa a quella totalizzante della chiesa ufficiale, decisa a recidere qualunque legame con forme di conoscenza tradizionale ancorate a retaggi precristiani. Secondo uno schema storico di sfida/risposta, il movimento alternativo delle streghe rappresenterebbe una sfida all’avanzare del cristianesimo ed alle sue pretese totalizzanti. Il temine “alternativo”, in relazione alle streghe, evoca quindi una reazione al dispotismo ed alla autorità che è apparso molto suggestivo in epoca recente, soprattutto se agli aspetti esoterici ed antiautoritari si mescolano forti elementi di libertà sessuale e di eguaglianza della donna.

Gli echi di questa cultura sono pervenuti nella nostra epoca, riproponendo in forme nuove la dinamica della sfida/risposta. Ma la società aperta di oggi non è quella della chiesa istituzionalizzata di ieri, e riproporre quella sfida tradotta in termini antiscientifici ed esoterici appare una totale assurdità. Seppure ci rappresentassimo come classe separata e contrapposta ad una classe dominante, sarebbe difficile considerarci estranei ad un sistema di produzione della scienza e del pensiero che ci pongano al di fuori della scienza e del sapere “istituzionale”. La “socializzazione” della produzione e del sapere ci rende tutti “complici” ad un certa maniera del sistema. La cultura alternativa diviene quindi una delle forme di produzione alternativa fra le tante, che non hanno alcun aggancio con la scienza vera e propria.

A questo punto, anche se non amo farlo, vista la mole di pubblicazioni in merito, è necessario parlare di omeopatia, esempio paradigmatico, per le persone razionali, dell’inconsistenza delle medicine alternative e della loto totale assenza di basi scientifiche. Conosciamo tutti (almeno spero), la storia del Dott. Hahnemann, il quale si convinse del principio divenuto famoso del similia similibus curantur dopo aver assunto ripetute volte dosi di Cinchona succirubra, la fonte del chinino, che gli aveva provocato sintomi quali: mani e piedi freddi, stanchezza e sonnolenza, ansia, tremore, prostrazione, mal di testa pulsante, arrossamento delle guance e sete, ma senza innalzamento della temperatura, una febbre senza febbre insomma. Quella che secondo alcuni, con ogni probabilità, non fu nient’altro che una reazione di natura allergica a detta pianta, divenne la fonte di ispirazione di una rivoluzione nel campo della medicina, rivoluzione che Hannemann stesso paragonò alla riforma protestante in campo religioso: per guarire una malattia bisogna creare una malattia artificiale che scacci la vera malattia.

Facciamo un breve riassunto. Forse risulterà pedante, considerato il numero di insigni giornalisti e studiosi che da anni ormai ci spiegano il significato delle diluizioni omeopatiche, ma un po’ di ripetizione non guasta. Il Prof Hahnemann era convinto, come abbiamo già accennato, che una quantità infinitesimale di quella stessa sostanza che provoca i sintomi nel sano, era in grado di curare quegli stessi sintomi nella persona malata. Le diluizioni centesimali per Hannemann, in base alla sua esperienza personale, rappresentavano la soluzione del problema. In pratica 1CH corrisponde ad un grammo di tintura madre diluita cento volte, 2CH ad una diluizione centesimale della prima diluizione, 3CH ad un ulteriore diluizione centesimale e così via, fino ad arrivare ad una diluizione di 30CH, una di quelle preferite da Hahnemann. Tradotto in numeri, 30 CH corrisponde ad 1 diviso 1 con 60 zeri. Qualcuno ha stimato che un grammo di sostanza iniziale a una diluizione centesimale di 30CH, finisce diluito ad un volume pari a 714 milioni di miliardi il volume del sole. Ai tempi di Hahnemann il principio di Avogadro formulato solo nel 1860 era sconosciuto (Hahnemann muore nel 1843). Tale principio stabilisce che una grammomecola o mole (peso molecolare espresso in grammi) contiene un numero fisso di molecole pari a 6,022x10²³. Una diluizione pari a 12CH non contiene praticamente neanche una molecola del composto originario e successive diluizioni non fanno che diluire una soluzione idroalcolica con altra soluzione idroalcolica. A questo punto sembrerebbe tutto risolto. Quella che poteva essere una teoria interessante per i tempi si rivela del tutto infondata alla prova dei fatti. Non è così semplice. Il motivo del persistere dell’omeopatia, come delle altre medicine alternative infatti non risiede nella loro validità comprovata e nemmeno nei loro fondamenti scientifici, il motivo risiede, come ho già detto, nel tasso di dissociazione psicotica presente nella popolazione di un società umana. Sappiamo benissimo che il delirio ha come principale caratteristica l’impermeabilità dei propri contenuti a qualsiasi confutazione, e nel momento in cui una tesi non è più sostenibile, il delirio permane ma in forme mutate. Ora sarebbe interessante fare una dissertazione sul significato di verità e sull’arbitrarietà del concetto di delirio, che non sarebbe altro che una convinzione non condivisa dalla maggioranza delle persone, ma bisogna ammettere che se la società è andati avanti nelle sue conquiste questo non è stato grazie alle paralogie del pensiero primitivo o al potere del pensiero magico e né all’evocazione di oscure divinità che animano il cielo durante i temporali o all’animismo che considerava la malattia un perturbazione dell’anima. Il progresso è avvenuto nel momento in cui si è affermato un procedimento empirico, un metodo di indagine della realtà e di ragionamento basato sulle evidenze dell’osservazione. Il delirio come pure il pensiero magico sono parte di una visione delle cose che misura la realtà di un fenomeno in base alla pura percezione soggettiva del vero e del falso.

Parlando di dati empirici, occorre sottolineare che il metodo non va confuso con la filosofia che da tale metodo trae origine, cioè con una visione del mondo che considera il dato empirico come elemento fondante della realtà e come criterio atto a raggiungere la verità. La confusione è derivata dall’identificazione, almeno inizialmente, della figura dello scienziato con quella del filosofo. Tale identificazione ha fornito poi il pretesto in epoche recenti per accomunare scienza e filosofia della scienza, facendo confusione fra chi usa la zappa per coltivare l’orto e chi fa discorsi sul significato e il valore della zappa. Oggi il valore euristico di un qualsivoglia metodo di ricerca, per uno scienziato, è solo funzionale al risultato della scoperta e non certo alla ricerca della verità o all’asservimento al paradigma di turno. La filosofia della scienza rappresenta spesso un campo per intellettuali che conoscono poco la puzza dei laboratori e che sanno poco o niente dei problemi degli scienziati.

In tutto questo contesto il pensiero paralogico e delirante rimangono sussunti all’interno del corpo sociale e ne rappresentano una costante storica.

Intendiamoci, non c’è nulla di male di per sé nel delirio, esso può essere l’epifenomeno di una malattia psichica, oppure come accennato un’attitudine del pensiero umano. Il problema nasce quando un tale pensiero assume una rilevanza tale da indurre a comportamenti aberranti e pericolosi, come quelli che rifiutano le terapie convenzionale contro il cancro e costringono i governi a dare credito a ciarlatani in buona e cattiva fede.

Tornando all’omeopatia, una volta screditato l’empirismo ingenuo del dottor Hahnemann, i seguaci dell’omeopatia non sono affatto scomparsi e per nulla scoraggiati hanno atteso pazientemente che emergessero nuove scoperte le quali potessero supportare le loro convinzioni con un background più solido e un aggancio scientifico più moderno. In definitiva il problema non è la ricerca della verità o di qualcosa che ci somigli, bensì l’affermazione delle proprie credenze aldilà di ogni discorso sull’evidenza. L’aiuto è giunto da un immunologo d’oltralpe, il Dott. Benveniste, il quale in un lavoro pubblicato su Nature nel 1998, affermò di aver dimostrato la proprietà dell’acqua di conservare la memoria di sostanze con le quali era venuta precedentemente a contatto, conservandone anche gli effetti terapeutici. Abbiamo già esaurientemente trattato l’affaire Benveniste in un post precedente e non mi dilungherò nei dettagli. È sufficiente dire che anche questa teoria è stata screditata aldilà di ogni ragionevole dubbio, sebbene l’entusiasmo degli omeopati fosse stato a mio avviso, in ogni caso, del tutto immotivato. Seppure la teoria si fosse dimostrata valida, infatti, da ciò non ne sarebbe conseguita una reale attività terapeutica dei preparati omeopatici, ma solo il principio che l’acqua conserva memoria, e non si sa quanto a lungo, di una determinata sostanza con la quale è venuta precedentemente a contatto. La dimostrazione della presunta attività dell’antianticorpo IgE messa in evidenza da Benveniste, riguarda infatti quel singolo caso specifico e non si presta a generalizzazioni. Ad ogni buon conto, nemmeno il discredito di questa ennesima teoria è stato sufficiente a far capitolare gli omeopati ed anche in questo caso sono spuntate altre teorie ancora più suggestive delle precedenti a soccorso dei seguaci del Dott. Hahnemann. Citiamo fra tutte quella di due scienziati italiani, due fisici, Giuliano Preparata ed Emilio Del Giudice, studiosi ben addentro a fenomeni complessi come la fusione fredda e le onde gravitazionali. Del Giudice e Preparata sostengono la teoria della “coerenza dell’acqua” in base alla quale, passando incessantemente da uno stato eccitato ad uno stato di base e poi di nuovo a quello eccitato, le molecole di acqua emetterebbero dei fotoni, fenomeno che ricorderebbe il comportamento dei fotoni nel caso di un raggio laser. In pratica secondo questa teoria il solvente acquoso risulterebbe “attivato” dal preparato omeopatico e dalle successive succussioni, generando una energia peculiare attiva anche quando ogni molecola del preparato iniziale non è più presente a causa dell’estrema diluizione. L’energia in questione sarebbe alla base dell’effetto dei composti omeopatici. Questa fantasiosa teoria è stata messa in crisi da molti fisici ed in particolare da Gianfranco Rocco dell’Università La Sapienza di Roma, che hanno tutti allo stesso modo segnalato un errore di fondo nella stessa teoria, in quanto l’acqua ha una probabilità molto minore di trovarsi spontaneamente nello stato eccitato rispetto a quello fondamentale e non sarebbe possibile una sua altalenante inversione da una condizione all’altra. Lo stesso Del Giudice sembra abbia recentemente ammesso l’errore e non parli più di fotoni sebbene insista nell’affermare che il concetto di fondo della proprietà dielettrica dell’acqua rimane. Come gli è stato fatto notare, però, questa proprietà non richiede l’ausilio di cervellotiche teorie che fanno ricorso alla fisica quantistica, sono sufficienti le teorie tradizionali per spiegarla.

Tempo fa ho avuto modo di discutere di questi argomenti in un sito famoso di sinistra e sono rimasto colpito dal credito che i pasdaran dell’omeopatia davano agli studi di questi due scienziati, ridicolizzando chiunque non avesse letto i loro lavori e tagliando di netto ogni contestazione che prescindesse dalla conoscenza del verbo di Preparata. Ora, è evidente che non tutti possono perdere il loro tempo per documentarsi su ogni oscura teoria di scarso impatto, per il semplice fatto che nessuno, tranne alcuni scienziati molto pazienti, che dedicano il loro tempo a contrastare fenomeni irrazionali, è motivato a farlo, visto che l’omeopatia non ha mai dato nessuna prova concreta della sua efficacia e che il mondo accademico è unanimemente concorde nel considerare l’omeopatia soltanto un ottimo placebo. L’opposizione a questa osservazione è scontata: il fatto stesso che il mondo accademico sia concorde in maniera compatta sull’omeopatia, è la dimostrazione della sua cattiva fede. Come è stato già affermato da più parti il sottofondo paranoicale dei cultori delle medicine alternative esclude ogni possibilità di argomentazione, dato che qualsiasi lavoro o studio che smentisca la credibilità delle medicine alternative è di per se la riprova dell’inganno delle case farmaceutiche guidate unicamente da interessi legati al profitto. Inutile sottolineare che questi interessi esistono davvero, ma gli sforzi di Big Pharma non sono certo concentrati a screditare fandonie che si screditano di per sé. Supporre che ci sia una congiura internazionale per nascondere al mondo questa panacea universale rappresentata dall’omeopatia è francamente assurdo, considerando il fatto che il fatturato dell’omeopatia non è affatto trascurabile e che esistono ovviamente anche le multinazionali omeopatiche.

Al di là di interessanti quanto impervie dissertazioni sulla fisica quantistica e sull’elettromagnetismo, vorrei sottolineare alcuni concetti chiave che a mio avviso rendono l’omeopatia e le medicine alternative in generale per nulla credibili.

Il primo punto riguarda l’idea appunto di un fronte compatto, capeggiato dalle multinazionali del farmaco, che cospirerebbero contro le medicine alternative. Quello che i fanatici di tali pratiche ignorano o fingono di ignorare è che questo fronte è in larghissima parte costituito, nelle sue articolazioni medio basse, da un ceto politico sociale, e sottolineo politico, che forma l’ossatura di quel ceto intellettuale o General Intellect o cognitariato che dir si voglia, il quale rappresenterebbe il nuovo soggetto politico, frutto della società post-fordista, che è portatore di istanze radicali di cambiamento. Per farla breve, la nuova classe su cui la prassi rivoluzionaria dovrebbe fare perno. Lino Rossi ed altri accaniti sostenitori di Preparata e Del Giudice, convinti assertori della teoria del complotto, si stupirebbero nel conoscere la percentuale di votanti e simpatizzanti della cosiddetta sinistra radicale presente fra i ricercatori e gli addetti alla ricerca, e guarda caso sono proprio questi soggetti che portano avanti ricerche sul piano statistico-epidemiologico che gettano discredito sull’omeopatia. La metanalisi di Lancet, prestigiosa scientifica medica che ha dimostrato dati alla mano l’inconsistenza dell’omeopatia in tutti quegli studi condotti con metodi rigorosi, non è stata certo portata avanti dai colletti bianchi di Big Pharma, ma da ricercatori che ingrossano le file del General Intellect odierno. Sono tutti venduti, tutti seguaci della dottrina del profitto?

Il secondo punto riguarda la curiosa rincorsa degli alternativi a nuove teorie che di volta in volta siano in grado di supportare le loro credenze, ogniqualvolta le precedenti crollano come birilli.

Non voglio dilungarmi oltre su tematiche che si addentrano in maniera troppo specifica in terreni complessi come quello della fisica dei quanti, vorrei solo far notare un fatto che salta agli occhi: la teoria inizialmente espressa da Hahnemann si basava sul concetto, come ho già evidenziato, del similia sumilibus curantur, e cioè una parte infinitesimale di quella sostanza che produce sintomi nel sano può curare gli stessi sintomi nella persona malata. Ora, dal momento che abbiamo appurato che i preparati omeopatici non contengono nulla, se siamo omeopati convinti dobbiamo dedurre che il Dott. Hahnemann abbia fatto la classica scoperta per serendipity, cioè a dire ha scoperto accidentalmente, partendo da ipotesi rivelatesi errate, un principio poi risultato valido ed in grado di supportare la sua teoria. Vi sembra credibile tutto ciò? A me non lo sembra affatto, soprattutto perché appare molto improbabile che le varie teoria sull’acqua si accordino poi con tutto l’insieme della teoria di Hahnemann, la quale difficilmente può essere scomposta in singoli tronconi indipendenti. Come concorda la teoria dell’acqua con quella dei miasmi o delle varie tipologie costituzionali con relativi rimedi omeopatici ? Non è strano poi che il Dott. Hahnemann con l’idea delle succussioni abbia incidentalmente trovato il sistema per dinamizzare l’acqua, che guarda caso si dinamizzerebbe proprio sottoponendo i contenitori a quei determinati movimenti verticali? E perché infine proprio quei rimedi dovrebbero funzionare in base alle predette teorie e non altri? In conclusione, l’idea della rincorsa alla spiegazione che disvela ciò che gli infedeli si rifiutano di vedere, da' il senso del totale rovesciamento della logica più elementare, che esigerebbe che la scoperta venga prima dell’enunciazione dei principi.

Il terzo ed ultimo punto riguarda a mio avviso il carattere di fissità dei principi che sono alla base dell’omeopatia. Come ha fatto giustamente notare il Prof. Dobrilla, la scienza medica si evolve continuamente e determinate certezze o ipotesi ritenute alla base di certe malattie sono smentite da nuove scoperte. Il Prof. cita il caso dell’ulcera duodenale, attribuita per anni quasi esclusivamente all’aggressività dell’acido cloridrico prodotto in eccesso dallo stomaco e/o alla diminuita capacità difensiva della mucosa duodenale, secondarie allo stress. In pratica una malattia psicosomatica. Oggi con la scoperta del ruolo ulcerogeno dell’Helicobacter pylori abbiamo scoperto una causa che sta portando alla quasi totale estinzione delle patologie ulcerogene e delle sue complicanze. Ebbene, vent’anni dopo questa scoperta, di questa rivoluzionaria acquisizione non c’è traccia nella letteratura omeopatica e i rimedi continuano ad essere gli stessi. Questo fatto di per se sarebbe da solo sufficiente a dimostrare l’infondatezza dell’omeopatia. Teorie statiche non sono adatte alla scienza, che per definizione si evolve di continuo e il cui sapere, sebbene per alcuni versi sia cumulativo, procede su una linea discontinua, che comporta spesso la negazione ed il superamento delle fasi precedenti. 

venerdì 25 settembre 2009

A homeopathic refutation – part three


ool's gold
In the third part of my series examining an attempted refutation of the critics of homeopathy (Milgrom, 2009) I look at the claim that homeopathy has a serious scientific foundation.
Dilute Science
This part of the essay starts by outlining a common criticism levelled at the most common form of homeopathy practised in the US and UK.  This calls homeopathy unscientific because:
[…] in many homeopathic remedies, the original substance has been diluted out of molecular existence, detractors claim belief in homeopathy has no basis in science as ‘nothing cannot do something’.”
So, can apologists for homeopathy point to serious scientific work which shows that nothing can do something?  Milgrom’s approach is to cite recent claims invoking concepts from materials science and physical chemistry to suggest that:
 “[…] homeopathy’s method of remedy preparation leads to modifications in the dynamic long-range supra-molecular ordering of solvent molecules; an effect called the ‘memory of water’”*.
Real science
Before examining the evidence Milgrom marshals, it is worth reflecting on what we should expect to see if it is really science.  This is a complex topic and there are many different descriptions of what, in practise, science is.
However, there is practically universal agreement that science is based on the formulation and testing of hypotheses.  This means that to be scientific an idea must be testable.  It also puts careful experimental practise at the core of science.
Also, as we all tend to become attached to our own ideas, even when there is evidence against them, scientific methods include strong precautions against scientists fooling themselves.  This is vital, as Feynman (1974) remarked, “The first principle is that you must not fool yourself – and you are the easiest person to fool.  So you have to be very careful about that.”
Central to this is the honest search for reasons why an idea might be wrong.  Feynman (1974) described the process as:
[…] a kind of scientific integrity, a principle of scientific thought that corresponds to a kind of utter honesty – a kind of leaning over backwards.  For example, if you’re doing an experiment, you should report everything that you think might make it invalid – not only what you think is right about it: other causes that could possibly explain your results; and things you thought of that you’ve eliminated by some other experiment, and how they worked – to make sure the other fellow can tell they have been eliminated.”
This includes testing hypotheses in ways that might break them.  It also means carefully comparing new ideas and results against previous work and established theory.
Scientific investigation also includes methods for limiting the influence of personal biases.  The advent of automated measurement systems means that the mistake of Blondlot  – imagining that he was seeing scintillations from non-existent N-Rays, because he was so personally invested in his ‘discovery’ – can be avoided. 
Where an experimenter or subject can subconsciously influence the result – medical trials being a good example – a real scientist takes proper precautions.  For instance, the investigators and subjects not knowing if they are receiving a new drug or a indistinguishable dummy (blinding) prevents them from being tempted to see ‘expected’ improvement where there is none. Making sure that if two groups are being compared they are as similar as possible, through assigning participants to them at random (randomization) is another precaution against being misled. 
Where measurements can vary because of factors outside of the scientist’s control, repeated measurements are made and statistically tested to see if two samples, for instance, are really different or if a measured difference is just happenstance. 
Finally, the use of controls – like making the same measurements on pure solvent from the same bottle used to make test solutions, for example – helps ensure that scientists are not fooled by the vagaries of the real world. 
Many experiments produce anomalous results.  In real science they are carefully examined in well-controlled experiments.  Detailed measurements are made and possible causes of error are progressively excluded.  Anomalies that survive this scrutiny may well go on to challenge current theories, but most melt away.  So real scientific investigators don’t leap to wild conclusions; they carefully seek the simplest explanation. 
So if Milgrom is really offering up examples of scientific investigations that support the basic plausibility of homeopathy, they will demonstrate these basic scientific virtues.  I expect to see careful, well documented experiments; possible flaws pointed out and explored; evidence of blinding and randomization, where appropriate; the presentation of statistical data where the experimental system produces varying results.  I also would not expect to see wild interpretations made of anomalous results; particularly if simpler explanations are possible. 
Homeopathic science
The evidence Milgrom provides on the topic of materials science relies on two publications involving Rustum Roy, an eminent materials scientist with an enviable publications record.  The only problem is that latterly he appears to have hitched his wagon to the alternative health movement.  This seems to have compromised his objectivity.
In Roy et al. (2005) we see a review of the many amazing and occasionally anomalous properties of water.  This work argues that the physical properties of water support the idea that homeopathic preparations can ‘remember’ what solute was originally added and diluted out of existence and, through structural changes, communicate this to patients. 
The problem is that the gap between what can be measured and that which is merely asserted to justify homeopathy is never closed.  The exercise is a lengthy non sequitur:  just because water has some anomalous properties doesn’t mean that it can remember what used to be dissolved in it. 
In reality, this paper is a collection of straws that are desperately clutched at.  Nowhere is this clearer than in the discussion of the potential for contamination in experiments purporting to study high-dilution remedies: 
Obviously chemical contamination from the container material could itself serve as a “remedy”.
This is both desperate and not obvious.  If contamination from containers could be the homeopaths actual remedies, then the remedies are uncontrolled and bear no resemblance to their claimed ingredients, or their supposed therapeutic effects.  The ‘remedies’ will be different each time and will vary between homeopaths.  A medical practise based on accidental contamination cannot be in any sense plausible, let alone ’scientific’.
The biggest problem with Roy et al. (2005) is that it confuses real measurable physical phenomena (electric and magnetic fields, for instance) with the immeasurable “subtle energies” of the CAM practitioner.  This beggars any claim to be a real scientific publication.   Citing silly papers that claim to be able to show the measurable effect of “human intention” and “qi” on chemical systems provides the final nail in the coffin.  This is not science.  It may have the appearance of science, but it lacks proper content.  A real scientific paper would critically examine paranormal claims, not just accept them at face value.
So, how is it that it appears to have been published in a scientific journal?  Actually, it’s not.  It’s published in Materials Research Innovations , Rustum Roy’s own journal; a publication that rejects peer review of papers in favour of reviewing the authors.  One consequence appears to be that if you have published some good work in the past, as Roy has, then you can publish any old nonsense in the future; as Roy and his co-workers demonstrate.
Next, the essay references Rao et al (2007).  This deeply flawed paper, published in the homeopathic vanity press, which claims to show that homeopathy is plausible because they came up with some spectrographic measurements that appeared to show differences between homeopathic remedies and their solvents.
As Kerr et al (2008) pointed out: the spectrum contained in the paper purporting to be ‘pure ethanol’ does not look like ethanol of any recognised degree of purity.  Further, from the paper, there is no way to know whether the reported differences between the spectra were the result of using solvent containing different levels of impurities.
Worryingly, it contains no statistical information, so no conclusions can be drawn as to whether the remedies were actually different. Finally, one graph was reproduced twice, with the authors claiming that it showed different things each time.
The author’s reply (Rao, 2008) failed to address any of these serious concerns.  Sticking your head in the sand when serious flaws are identified in your work is not doing real science.  There again, this was published in the journal Homeopathy, which is clearly not a real science journal.
Let’s get physical
So, no real science so far: just an enthusiasm for sloppy work and the paranormal.  What about the evidence that Milgrom sees coming from physical chemistry? 
Samal and Geckler (2001) is cited because this reports evidence that water molecules ‘clump’ around solutes; tending to form bigger clumps at lower solute concentrations.  How does this help the argument that there is a scientific rationale supporting the effect of solutions where the solute is highly unlikely to have survived successive dilutions?  Quite simply: it does not.  Any structures formed around solute ions will be finite in number and diluted out of solution: just as any finite solute concentration of anything will be.  At least this paper is real science; but it says something that it definitely does not support the claims of homeopathy.
The next anomaly that is cited to show the scientific plausibility of homeopathy is provided by Rey (2003).  In this study a technique called Thermoluminescence was used to study samples of frozen heavy water (D2O); some of which were the result of diluting preparations of lithium chloride and sodium chloride beyond the point where any molecules of these salts could be expected to be found in the solution.  This process replicated a homeopathic method of ‘remedy’ preparation: successive 1:100 dilutions with vigorous mechanical shaking (succussion) at each step.
Thermoluminescence is the, “emission of light from some minerals and certain other crystalline materials” as their temperature is raised.  The energy of this emission is, “derived from electron displacements within the crystal lattice of such a substance caused by previous exposure to high-energy radiation.”  Heating the material, “enables the trapped electrons to return to their normal positions, resulting in the release of energy.”  (Encyclopædia Britannica, 2009)
This is a proper scientific technique, generally used to date archaeological artefacts and minerals.  Rey appears to be pioneering its application to the study of frozen solutions – assuming that structures in the liquid phase will be preserved by freezing. 
Although the Rey (2003) claims that, “despite their dilution beyond the Avogadro number, the emitted light was specific of the original salts dissolved initially” it provides few details for a paper advancing such a radical hypothesis.  The investigation of the ‘highly dilute’ samples (C15 LiCl, C15 NaCl and C15 D2O) did not include an obvious control: the unsuccussed solvent (D2O) making it impossible to separate the putative influence of the (non-existent) salt ions from changes made by shaking the samples.
Neither did Rey provide any statistical information, so there is no way of telling if the differences measured were real, or just down to chance.  As a contributor on this blog has noted:
[…] the scientific basis of the emissions recorded – “what do these kind of readings tell us?” […] is actually pretty obscure. The technique relies on freezing the sample, irradiating it in one of a number of ways, and then watching the thermoluminescence emissions while the sample re-warms. The general message is that the emissions depend upon “structural irregularities” in the crystal lattice of the frozen sample, but the details, to repeat, are poorly understood.”
If there really are differences between the C15 ‘dilutions’ then what might be the cause?  Rather than grasping at implausible explanations, a real scientific approach eliminates the mundane.  For instance, could it be that shaking the solutions has changed their physical characteristics?  Rey (2007) has gone on to explore the possibility that vigorous shaking causes the formation of ‘nanobubbles’ in the solutions, and that these, when frozen, provide the structures associated with the thermoluminescence spectra.  The investigation looked at the spectra generated by samples “succussed” under the standard laboratory atmosphere, pure oxygen and vacuum.  The spectra appear to be different but, again, no statistical data was included to allow a reader to be sure.
Construing this work as evidence of a scientific basis for the claims of homeopaths is unwarranted.  Yes, it is science of a sort; it’s not without flaws and obvious biases.  Neither is it very convincingly reported.  However, all it provides is evidence for the presence of not very well understood structures in heavy water ice.  There is some evidence that they are associated with the shaking of the solutions, but the missing control (unsuccussed D2O) limits the conclusions that can be drawn.  In fact, I would say that Rey’s contention that the spectra were specific to the salts goes too far, as he was not in a position to separate the implausible influence of the absent chemicals from that of the process by which his solutions were made.
One of the key values in science is that of replication.  If independent scientists, working in other places, can get the same result from the same experiment then this helps separate knowledge from happenstance.  Milgrom claims that the findings in Rey (2003) were replicated by van Wijk et al. (2006).  They were not.
This work did try and replicate and extend the findings of Rey (2003).  Using Lithium Chloride (LiCl) as the solute and heavy water as the solvent (D2O) they also explored the possible influence of, “time between preparation of substance and time of experimentation, and […] time between irradiation and thermoluminescence recording”.
Unlike Rey (2003) van Wijk et al. (2006) presented a statistical analysis of their measurements.  Their like-for-like attempted replication failed:
We report here differences in thermoluminescence between C15 D2O and C15 LiCl, which correspond with the observations reported by Rey (2003).  However, the difference from all of these recordings of these substances was not statistically significant.”
In the replication experiment (A) the difference between C15 LiCl and C15 D2O did not reach statistical significance (p = 0.059, ANOVA t-test).  In the experiments that looked at the influence of the time between sample preparation and freezing, or the time between irradiation and thermoluminescence measurement (B and C) There wasn’t even a hint of a significant difference (p = 0.72, and p = 0.63, respectively, ANOVA t-tests).
However, they did report some statistically significant differences.  When the data were processed differently the result suggested that LiCl C15 differed significantly from C15 D2O in experiment A (p = 0.0128); but not in experiments B and C. (p = 0.60 and 0.73, respectively).
The best evidence of a difference between samples was seen in the comparison between the succussed (C15 D2O) and unsuccussed (D2O) solvent for experiment C.  This used the maximum time between sample preparation and freezing (12 weeks), and between irradiation and thermoluminescence measurement (3 weeks).  The result was statistically significant under both data processing methods (p<0.0001, and p<0.0004, respectively).
It’s clear that van Wijk et al. (2006) did not replicate the findings of Rey (2003), as Milgrom and, indeed, Rey (2007) has claimed.  There might be an interesting anomaly to pursue here, but there is no real evidence of absent solutes being the cause.  Van Wijk et al. (2006) does show that the experimental system is a ‘noisy’ one and that careful statistical analysis is required.
The point must be stressed that we obtained a very good qualitative reproducibility of the thermoluminescence pattern, but the quantitative reproducibility was rather poor, and p-values should be interpreted in the sense of descriptive statistics.”
This emphasises that the lack of statistical data in Rey (2003) is a serious flaw: most of van Wijk et al.’s comparisons did not show statistically significant differences.  
The differences reported between the succussed and unsuccussed solvents also strengthen the impression that any differences are more likely the work of nanobubbles and not a watery memory of long gone solutes.  Again, this highlights Rey’s oversight in not using unsuccussed solvent as a control.  In a delightful irony even Roy et al. (2005) show they understand the potential importance of this omission:
It is important to emphasize that the proper control solutions include not only untreated, unsuccussed solvent, but also succussed solvent without the initial addition of any remedy source materials to address possible artifacts generated by the shaking of the liquid per se within the test container itself.”
So, van Wijk et al. (2006) seems to contain science, but it doesn’t help the homeopath’s cause.
Next the essay sees scientific support in the work of Elia et al. (2006).  This is another attempt to find physically measureable differences between homeopathic solutions that do not contain any of the original solutes and their solvents.  It’s also based on very different physical principles to thermoluminescence.  This adds to the impression that this is just chasing after anomalies.  I don’t have access to this paper, so I’ll not comment further.  However, in 2007, the same author (Elia, 2007) published a review of the evidence they had accumulated. 
It’s not very impressive: no statistical data are provided to help the reader understand if any differences are significant or not.  Neither is there any indication of how many times (if at all) measurements were repeated.   It also contains an odd confession:
It is important to emphasise that, from the studies so far conducted, we cannot derive reproducible information concerning the influence of the different degrees of homeopathic dilution or the nature of the active principle (solute) on the measured physicochemical parameters.”
If different concentrations of homeopathic preparations cannot be distinguished, then it casts serious doubt on any claims to be able to differentiate between homeopathic preparations.   This is really clutching at straws**.
The attempt to show that homeopathy is grounded in science peters out from here.  An irrelevant theoretical speculation on Quantum Electrodynamics (QED) is thrown in to the mix (Arani et al., 1995).  Martin Chaplin’s fascinating website on the properties of water is also referenced.
Milgrom also resorts to an inappropriate analogy:
Just as two physically contrasting substances, such as diamond and graphite, are composed of exactly the same carbon atoms arranged into different molecular structures, so it is not the composition of an ultra-diluted homeopathically-prepared solution that is different from plain diluted solvent, but its dynamic supra-molecular structure.”
Well, diamond and graphite both have structure – being solids – liquid water does not (Teixeira, 2007).  Clearly, there is no “just as” about it!  The rest is just unsupported opinion. 
The same can be said of the reference to Hankey (2004) who provides evidence and data-free hand waving of a distinctly unscientific variety.  Here is a sample:
In this model, all vibrational medicines are quantized fluctuations, of mineral, vegetable, animal, mental, psychic, or spiritual origin. Succussion and dilution potentize the first; correct formulation of phytomedicines, the second; while the last four are all involved in various levels of healing. For example, in Maharishi Vedic Vibration Technology (Nader et al., 2001), use of a mantra develops the specific healing vibration within the technician’s nervous system, for transferal to the patient.”
The appeal to some kind of quantum theory is bogus***.  The rest either has no meaning or is paranormal.  This is not science and by citing it Milgrom eloquently debunks his own argument.
A poor memory
And that is it; Milgrom presents this as a refutation of the claim that homeopathy has no scientific basis.  At best his argument rests on a few anomalous experimental results (Rey, 2003; Elia et al, 2006), which are likely to be explained by very ordinary causes: bubbles causing by shaking, chance readings in noisy experimental systems, contaminated samples, etc. 
The better work he refers to doesn’t help either.  Van Wijk et al. (2006) fails to provide the replication of Rey (2003) that Milgrom (and Rey, 2007) claims.  Samal and Geckeler (2001) does not provide a way for homeopaths to cheat Avogadro.
Much of the rest actually provides an elegant confirmation of the critics’ accusation by ignoring scientific values and asserting the reality of imaginary ‘energies’. (Roy et al., 2005; Hankey, 2004)
It is clear that Milgrom believes that water has a ‘memory’.  Unfortunately this is not just unsupported by scientific evidence; it is contradicted by it (Teixeira, 2007).  The quality of the evidence Milgrom has marshalled here bears witness to that fact.
If Milgrom really wants to turn to science, then he needs to rediscover its essential integrity:
[…] it’s this type of integrity, this kind of care not to fool yourself, that is missing to a large extent in much of the research in Cargo Cult Science.”  (Feynman, 1974)
Of course, this would entail leaving the Cargo Cult Science of the homeopathic apologist behind.  From the evidence on display here, I don’t think that’s very likely.
Next, I’ll have a look at what Milgrom has to say about homeopaths, the pharmaceutical industry and money.
Also in this series
A homeopathic refutation – part one – evidence. (on this blog)

Disclaimer
I try to make sure that what I write is both accurate and fair.  If you think that I have got anything wrong please let me know.  If you are right I will happily change what I have written.
Notes
* See here for my summary of the “Memory of Water” issue of the pseudo-journal Homeopathy.
**Interestingly Elia et al. (2008) published a conductivity study purporting to show the effect of aging on homeopathically prepared solutions.  This was strongly criticised by Corti (2008) who asserted that: the equipment used is not capable of taking measurements of the sensitivity reported; samples were stored over time in brown glass bottles, which are known to leak conductive ions such as Fe and Ni; the shifts in conductivity over time were cyclical over the period of a year and best explained by annual shifts in temperature.  The criticisms were strongly rejected by Elia (2008).
*** See here for a demolition of Hankey’s “physics”.
For completeness, the final reference in this part of the essay [33] is to Collins JC: Water: The Vital Force of Life. Molecular Presentations. New York, Kinderhook, 2000.   This is out of print, but Amazon carries some details. 
References
thermoluminescence.” Encyclopædia Britannica. 2009. Encyclopædia Britannica Online. 25 Sep. 2009 Available from: http://www.britannica.com/EBchecked/topic/591643/thermoluminescence
Arani R, Bono I, Del Giudice E, Preparata G. QED COHERENCE AND THE THERMODYNAMICS OF WATER. International Journal of Modern Physics B. 1995;9(15):1813–1841. Available from: http://dx.doi.org/10.1142/S0217979295000744
Corti H. Comments on “New Physico-Chemical Properties of Extremely Dilute Solutions. A Conductivity Study at 25 °C in Relation to Ageing”. Journal of Solution Chemistry. 2008 December;37(12):1819–1824. Available from: http://dx.doi.org/10.1007/s10953-008-9335-6.
Elia V, Elia L, Cacace P, Napoli E, Niccoli M, Savarese F. ’Extremely diluted solutions’ as multi-variable systems. Journal of Thermal Analysis and Calorimetry. 2006 May;84(2):317–323. Available from: http://dx.doi.org/10.1007/s10973-005-7266-7.
Elia V, Napoli E, Germano R. The ’Memory of Water’: an almost deciphered enigma. Dissipative structures in extremely dilute aqueous solutions. Homeopathy. 2007 July;96(3):163–169. Available from: http://dx.doi.org/10.1016/j.homp.2007.05.007.
Elia V, Napoli E, Niccoli M, Marchettini N, Tiezzi E. New Physico-Chemical Properties of Extremely Dilute Solutions. A Conductivity Study at 25°C in Relation to Ageing. Journal of Solution Chemistry. 2008 January;37(1):85–96. Available from: http://dx.doi.org/10.1007/s10953-007-9215-5.
Elia V. Response to Comments on a “New Physico-Chemical Properties of Extremely Dilute Solutions. A Conductivity Study at 25°C in Relation to Ageing” by Horacio R. Corti. Journal of Solution Chemistry. 2008 December;37(12):1825–1826. Available from: http://dx.doi.org/10.1007/s10953-008-9345-4
Feynman RP. Cargo Cult Science. Engineering and Science. 1974 June; pp. 10–13. Available from: http://calteches.library.caltech.edu/51/2/CargoCult.pdf.
Hankey A. Are We Close to a Theory of Energy Medicine?  Journal of Alternative and Complementary Medicine. 2004 February;10(1):83–86. Available from: http://dx.doi.org/10.1089/107555304322848995
Kerr M, Magrath J, Wilson P, Hebbern C. Comment on “The defining role of structure (including epitaxy) in the plausibility of homeopathy”. Homeopathy : the journal of the Faculty of Homeopathy. 2008 January;97(1). Available from: http://dx.doi.org/10.1016/j.homp.2007.10.004
Milgrom LR. Under Pressure: Homeopathy UK and Its Detractors. Forsch Komplementmed. 2009 September;16(4):256–261. Available from: http://dx.doi.org/10.1159/000228916
Rao M, Roy R, Bell I, Hoover R. The defining role of structure (including epitaxy) in the plausibility of homeopathy. Homeopathy. 2007 July;96(3):175–182. Available from: http://dx.doi.org/10.1016/j.homp.2007.03.009.
Rao M. Authors’ reply to Kerr et al. Homeopathy. 2008 January;97(1):45–46. Available from: http://dx.doi.org/10.1016/j.homp.2007.11.011
Rey L. Thermoluminescence of ultra-high dilutions of lithium chloride and sodium chloride. Physica A: Statistical Mechanics and its Applications. 2003 May;323:67–74. Available from: http://dx.doi.org/10.1016/S0378-4371(03)00047-5.
Rey L. Can low-temperature thermoluminescence cast light on the nature of ultra-high dilutions?  Homeopathy. 2007 July;96(3):170–174. Available from: http://dx.doi.org/10.1016/j.homp.2007.05.004.
Roy R, Tiller WA, Bell I, Hoover MR. The Structure Of Liquid Water; Novel Insights From Materials Research; Potential Relevance To Homeopathy. Materials Research Innovations. 2005;9(4):577–608. Available from: http://www.rustumroy.com/Roy_Structure%20of%20Water.pdf
Samal S, Geckeler KE. Unexpected solute aggregation in water on dilution. Chemical Communications (Cambridge, England). 2001 November;(21):2224–2225. Available from: http://dx.doi.org/10.1039/b105399j.
Teixeira J. Can water possibly have a memory?  A sceptical view. Homeopathy. 2007 July;96(3):158–162. Available from: http://dx.doi.org/10.1016/j.homp.2007.05.001.
van Wijk R, Bosman S, van Wijk EP. Thermoluminescence in ultra-high dilution research. Journal of Alternative and Complementary Medicine (New York, NY). 2006 June;12(5):437–443. Available from: http://dx.doi.org/10.1089/acm.2006.12.437.
Acknowledgements
dvnutrix for pointing me at this nonsense.
DrAust for his insightful comments on thermoluminescence.
Philippe Leick for his comments on Rey (2003) and van Wijk et al. (2006)
gnu and Acleron for their comments on Elia et al. (2007) during the Homeopathy journal club run at Badscience.net.

martedì 15 settembre 2009

A homeopathic refutation – part two

by apgaylard (from A canna' change the laws of physics)



This post is the second in a series examining the claims made in a recent essay that seeks, in part, to refute common criticisms of homeopathy (Milgrom, 2009).  I have already examined the empty assertions about evidence for clinically useful specific effects.  Now, I would like to move on to examine an attempted refutation of claims that, “Homeopathy is deadly”.

How deadly is homeopathy?

moronMilgrom starts with a bit of distraction: “The claim that homeopathy is deadly has never been substantiated, primarily because it cannot be proved anyone has died as a direct result of taking a homeopathic remedy.” 
This is entirely irrelevant; no critical discourse that I have come across has made the claim that the remedies themselves are toxic*.  As I pointed out in my last post: the problem is not in the pills, but in their uselessness; and the attitudes of some homeopaths.  He then moves to the actual concerns of sensible critics: 
The claim arises over concerns that those taking homeopathic remedies might forgo ‘life-saving’ drugs. This is a false perception: many who come to homeopathy do so only after conventional treatments have failed.”
And this is not right either: those who are able to turn to homeopathy after conventional treatment has failed are not going to be suffering from life-threatening illnesses.  They are generally people who are suffering from chronic complaints for which modern medicine has no good treatments (such as certain kinds of back pain, stress, medically unexplained fatigue, and modest viral illness – Goldacre, 2007).  The danger, such as it is, lies in choosing homeopathy instead of proper medicine for serious illness. That many will be using homeopathy to treat illnesses that are not life-threatening doesn’t mean that all users (or practitioners) of homeopathy are as conservative.
Milgrom’s rejection of any suggestion that homeopathy can harm is disappointing.  There are documented cases of people choosing homeopathy, or having it chosen for them, and dying as a direct result.  The number of fatalities appears to be low, but denying that there is any problem at all is rash. 
For instance, Gloria Thomas died at nine months of age, from sepsis, after her homeopath father ‘treated’ her eczema with homeopathy instead of seeking proper medical aid.  A UK GP, Dr Marisa Viegas was eventually struck-off after a she advised a patient with idiopathic dilated cardiomyopathy to take homeopathic treatments instead of the drugs she needed.  The patient died as a result. 
An example of the dangers of the disregard that some homeopaths show for conventional medicine and evidence is seen in the untimely death of Russell Jenkins, a CAM practitioner.  He took the advice of homeopath Susan Finn, who suggested that he treat an electrical burn with Manuka honey.  As a result of this improper treatment, he died from gangrene.  This is a different form of harm, but no less dangerous. 
Add to this the documented incidents of UK homeopaths advocating homeopathy for malaria prophylaxis and the activities of homeopaths in developing countries who believe they can treat AIDS and malaria: there are real risks. 
Again, I would not want to over-state the problem; but it is inappropriate for Milgrom to ignore it. 

Other homeopathic harms
Not all the harms of homeopathy are directly deadly ones.  A risk analysis that only focuses on extreme outcomes is too simplistic: there are real harms that don’t kill.  For instance, Goldacre (2007) identified a range of other risks associated with homeopathy.  These include medicalisation, “the reinforcement of counterproductive illness behaviours, and promotion of the idea that a pill is an appropriate response to a social problem, or a modest viral illness.” 
Also, by knowingly prescribing placebos medical practitioners can undermine the notions of informed consent and patient autonomy.  
As Milgrom’s essay shows, homeopaths are apt to denigrate conventional medicine.  This attitude can also lead some homeopaths to undermine public-health campaigns, like those promoting vaccination
Finally, as Milgrom shows, homeopaths have a tendency to misrepresent scientific evidence, undermining the public understanding of both science and medicine. 
It is important to recognise that even placebo medicine has a range of risks associated with it. 

What are homeopaths for?
Milgrom then moves on to flirt with the placebo effect.  After making what we have seen is the unjustifiable assertion that there, “is evidence to support homeopathy is more than a placebo response.”  He notes that, “homeopaths like other health practitioners, responsibly encourage expectation of positive outcomes”.  This is fair enough.  The evidence shows that any benefit that homeopaths deliver through the therapeutic encounter is due to expectation effects (Shang et al, 2005).  If homeopaths were open about this then, perhaps, there could be a role for them in a clinical setting. 
However, there is a sizable fly in the ointment.  As Milgrom says, health practitioners, “responsibly encourage expectation of positive outcomes.”  Proper medical practitioners can deliver specific effects through their interventions, along with non-specific expectation effects.  They also have the advantage of diagnostic training and don’t disparage other medical disciplines.  Given this, who needs homeopaths? 
Neither does encouraging positive expectations reduce the risks involved with homeopaths pretending to treat malaria, AIDS or other dangerous diseases.  This line of attack has little relevance to the matter at hand. 

Wouldn’t that be NICE?
Similarly irrelevant are the author’s claims about Prozac: a particular pharmaceutical being either ineffective or unsafe doesn’t mean that homeopathy is either effective or safe.  Anyway, Milgrom’s analysis is problematic in its own right: 
One of the world’s top-selling drugs, the anti-depressant Prozac, was recently shown to be no better than placebo [22]. Yet, with an effect size of only d ~ 0.3 (the National Institute for Health and Clinical Excellence – NICE – recommends d = 0.5 for clinical efficacy), there are no urgent calls for Prozac’s withdrawal through ‘lack of efficacy’.”
His reference [22] is to Kirsch et al. (2008) and it does not say what he claims it says.  First, this paper looks at what evidence was available before Prozac was licensed, not the totality of the data.  As Ben Goldacre has observed**:
It is common for quacks and journalists to think that the moment of licensing is some kind of definitive “it works” stamp of approval. It’s not, it’s just the beginning of the story of a drugs’ evidence, usually.”
So this paper does not show what the best evidence is for the efficacy, or otherwise, of Prozac (fluoxetine) for the treatment of depression.
Milgrom has also confused the result for a specific drug, fluoxetine, with a pooled analysis of all the drug groups against their placebo groups (Table 2, Model 3a).  The paper says that the drug group: 
[…] does not meet the three-point drug–placebo criterion for clinical significance used by NICE. Represented as the standardized mean difference, d, mean change for drug groups was 1.24 and that for placebo 0.92, both of extremely large magnitude according to conventional standards. Thus, the difference between improvement in the drug groups and improvement in the placebo groups was 0.32, which falls below the 0.50 standardized mean difference criterion that NICE suggested.”
So, this is where Milgrom’s “d ~ 0.3″ comes from.  It does not relate specifically to fluoxetine, but rather to a pooled analysis for all the drugs covered in this review.  In fact, the mean difference between the drug and placebo groups, “easily attained statistical significance.” 
The paper does show that the drugs studied achieved both statistically and clinically significant improvements, compared to placebo, for the most severely depressed.  As Figure 3 shows (below), they also exceeded the NICE criterion for these patients (the green bit).
Kirsch_Figure_3
Neither does the essay contain any mention of the weaknesses of this study, or the criticisms that have been levelled at it***.
Milgrom’s argument is further weakened by the fact that NICE have, since 2004, taken the position that:
Antidepressants are not recommended for the initial treatment of mild depression, because the risk–benefit ratio is poor.”
So, for cases where the evidence does not support the use of drugs like Prozac, NICE recommends they are not used.
Here Milgrom overstates the scope of Kirsch et al. (2008) by implying that it is a definitive assessment of the efficacy of Prozac.  He also turns the argument into a simple binary choice: either the drug works or it doesn’t.  Reality is more complicated: the effectiveness of this (and other) drugs varies with the severity of the depression.  Whilst they may not be justifiable treatments in some cases, they are in others.
By arguing that drugs which don’t meet the NICE criteria should be withdrawn, he is also setting the bar too high for homeopathy.  It’s notable that he provides no “d” values for any single homeopathic treatment.  Prozac may not be very useful for treating all but the most severe cases of depression, but there is no evidence that homeopathy can help at all.  After reviewing the literature Pilkington et al (2005) concluded:
Evidence for the effectiveness of homeopathy in depression is limited because of a lack of high-quality clinical trials.”
I am sure that it’s possible to argue that anti-depressants are over-prescribed and their benefits are at times over-stated.  However, their limitations appear to be appreciated by the medical community and strategies are in place to align their use with the available evidence.  There may be legitimate controversy here, but it is clear that drugs like fluoxetine have some benefit, compared to placebo: not the zero benefit Milgrom alleges.  Furthermore, Milgrom appears to have misunderstood the paper he has cited: ascribing the results for a pooled analysis of number of drugs to a single drug.  He also has missed the guidance from NICE to limit the use of anti-depressants based on their risk-benefit ratio.
This essay is meant to be making the case for homeopathy.  In this context the discussion of Prozac is irrelevant.  This section of the essay is also meant to be overturning the notion that homeopathy is dangerous; again, a flawed analysis of Kirsch et al. (2008) does not contribute to this objective.

Real medicine has risks … but are they this big?
Then again, neither does his next argument, which claims that:
Those who denounce homeopathy as ‘deadly’ should consider conventional medicine’s safety record; something recently scrutinised by the UK’s House of Commons Public Accounts Committee [23]. Including fatalities, this committee found that in 2006 alone, at least 2.68 million people were harmed by conventional medical interventions; representing 4.5% of the UK population …”
Milgrom’s reference [23] is this report:
Leigh E: A safer place for patients: Learning to improve patient safety. 51st report of session 2005–06 report, together with formal minutes, oral, and written evidence. House of Commons papers 831, 2005–06, TSO (The Stationery Office). July 6, 2006.
It can be found here.  The first thing that stands out is that it was published in early July 2006: so it’s obvious that it cannot provide data for “2006 alone”.  This raises some suspicion about the rest of the claims.
As does the fact that I cannot find Milgrom’s figures in this report.  What Leigh (2006) examines is how patients can be treated more safely.  It looks at the incident reporting systems in the NHS, along with how it can better learn lessons when things go wrong.  It does not provide any estimates of the number of people “harmed by conventional medical interventions”.  It’s concerned with episodes of unintentional harm: medical accidents.  On this specific topic it quotes a previous report which, “estimated that one in ten patients admitted to NHS hospitals are unintentionally harmed”.   This is consistant with a recent report on patient safety from the House of Commons Health Committee (Barron, 2009).
So, if we take this rate of harm and apply it to 2006, how close do we get to Milgrom’s figures?  For the year 2005/06 the NHS Hospital Episode Statistics count 12,678,628 admission episodes.  If one in ten of these admissions resulted in harm, this implies around 1.3 million incidents of harm.  The report cites nothing which would allow us to assess the number of people harmed, or include medical accidents that may occur to patients who were not admitted to hospital (under the care of a GP or treated as an out-patient, for example). This report only provides information on harm done to hospital in-patients; and a crude estimate at that.
Terry et al(2005) also points out that injuries due to falls ranks as one of the most common causes of these incidents.  To place these events at the feet of conventional medicine, rather than the process of caring for the sick, would seem to be harsh.
Finally, it is, of course, not valid to relate this figure to the UK population as the data refers to incidents not individuals.
Either I’m missing something (always a possibility) or Milgrom’s figures must come from elsewhere.  It might be that they are correct and that this is just a mis-citation.  In any case, he should make clear where these numbers actually came from.
Ultimately this is another irrelevance.  The rate of harm resulting from conventional medicine must be set against the benefits it delivers.  We have seen that homeopathy’s magic pills and potions may offer no risk in themselves – because they don’t contain anything – but neither do they provide any benefit. 
It must also be recognised that conventional hospitals often care for desperately sick people with complex conditions: under these circumstances mistakes are more likely.  However, Milgrom’s simplistic analysis makes no attempt to do this, rendering it useless.  Further, it has no relevance to concerns about the safety of the practise of homeopathy.  It’s just a bit of tu quoque.
Ultimately, all healthcare providers should be striving to do less harm.  The rate of medical accidents within the UK’s NHS – whilst comparable to that in other developed countries – is still too high.
However, safer medical practise should also include stopping homeopaths treating serious medical conditions and the abandonment of medical interventions that incur risk without benefit. 

Critics refuted?
So has Milgrom managed to refute the charge that, “Homeopathy is deadly and those who practice it are at best purveyors of a placebo effect”?  I don’t think so.   This part of the essay is very weak.
It  steadfastly ignores the documented incidents of harm caused by homeopaths treating serious diseases.  His concept of homeopathic damage is simplistic, limited to deaths which are not acknowledged.
It may be that homeopaths, “responsibly encourage expectation of positive outcomes”.  But that is all they have.  Real medicine can offer this and more: effective treatments.
Going on the offence, Milgrom offers nothing more than two examples of ill-founded tu quoque.  First, nasty critics call homeopathy a placebo, so he says Prozac is nothing more than a placebo.  Of course, that’s not really true; Milgrom has mis-read the evidence, not acknowledged its limitations and ignored the effectiveness of anti-depressants under particular circumstances.  He also invokes NICE criteria when discussing Prozac, even though it’s clear that no homeopathic intervention could meet this standard, unlike the drug he disparages.
Similarly, critics say homeopathy is dangerous, so Milgrom says conventional medicine is too.  However, the source of Milgrom’s figures is obscure – they do not come from the report he cites.  Neither are they relevant: the failings of conventional medicine don’t make homeopathy any better.  And even with its failings conventional medicine is massively more successful than homeopathy can ever be.
All-in-all this is an empty attempt to justify an empty practise.  The scholarship is slap-dash and the arguments are flawed.  It is hard to imagine that this essay was subject to any meaningful review.
Next, I’ll look at Milgrom’s attempted refutation of “The claim that homeopathy is unscientific”.

Also in this series
Disclaimer
I am not a doctor.  This does not constitute medical advice.  If you need that consult a properly qualified and registered medical practitioner.
These are just my opinions, but I try to make sure that what I write is both accurate and fair.  If you think that I have got anything wrong please let me know.  If you are right I will happily change what I have written.

Notes
*Not all homeopaths use non-existent ‘medicine’.  Some of these could be toxic.
**Ben Goldacre made some interesting observations on this paper in a piece published in the Guardian, “A quick fix would stop drug firms bending the truth” (blog version)
***The Pyjamas in Bananas blog has looked at this paper in detail and provides a good reference for this controversy.  This topic is clearly more complex than the caricature provided in this essay suggests.

References
Barron K, (chairman). Patient Safety – Health Committee – Sixth Report of Session 2008-09 – Volume I: Report, Together with Formal Minutes. London: The Stationery Office Limited; 2009. Available from: http://www.publications.parliament.uk/pa/cm200809/cmselect/cmhealth/151/151i.pdf.
Goldacre B. Benefits and risks of homoeopathy. The Lancet. 2007 November;370(9600):1672–1673. Available from: http://dx.doi.org/10.1016/S0140-6736(07)61706-1.
Kirsch I, Deacon BJ, Huedo-Medina TB, Scoboria A, Moore TJ, Johnson BT. Initial Severity and Antidepressant Benefits: A Meta-Analysis of Data Submitted to the Food and Drug Administration. PLoS Med. 2008 February;5(2):e45+. Available from: http://dx.doi.org/10.1371/journal.pmed.0050045.
Leigh E, (chairman). A safer place for patients: Learning to improve patient safety. 51st report of session 2005/06.  Report, together with formal minutes, oral, and written evidence. London: The Stationery Office Limited; 2006. Available from: http://www.publications.parliament.uk/pa/cm200506/cmselect/cmpubacc/831/831.pdf
Milgrom LR. Under Pressure: Homeopathy UK and Its Detractors. Forsch Komplementmed. 2009 September;16(4):256–261. Available from: http://content.karger.com/ProdukteDB/produkte.asp?Aktion=ShowAbstract&ArtikelNr=228916&Ausgabe=248719&ProduktNr=224242
Pilkington K, Kirkwood G, Rampes H, Fisher P, Richardson J.  Homeopathy for depression: a systematic review of the research evidence. Homeopathy : the journal of the Faculty of Homeopathy. 2005, July; 94(3):153–163. Available from: http://view.ncbi.nlm.nih.gov/pubmed/16060201.
Shang A, Huwiler-Müntener K, Nartey L, Jüni P, Dörig S, Sterne JA, et al. Are the clinical effects of homoeopathy placebo effects?  Comparative study of placebo-controlled trials of homoeopathy and allopathy. Lancet. 2005;366(9487):726–732. Available from: http://dx.doi.org/10.1016/S0140-6736(05)67177-2.
Terry A, Mottram C, Round J, Firman E, Step J, Bourne J. A safer place for patients: learning to improve patient safety. London: National Audit Office; 2005. Available from: http://eprints.whiterose.ac.uk/3427/.

Acknowledgements
dvnutrix for pointing this nonsense out to me.


Part one – originalon this blog