Evaluation of specific and non-specific effects in homeopathy: Feasibility study for a randomised trial

Abstract

Objective: To determine the feasibility, in terms of acceptability to patients, physicians and other staff; data return and statistical power of a study to elucidate the relative contributions of specific and non-specific effects in homeopathic treatment of dermatitis.

Design: Randomised, controlled 4-arm trial, 2 arms double-blind.

Setting: Outpatient clinic, Royal London Homoeopathic Hospital.

Participants: Seventy-five adult patients with dermatitis.

Interventions: Patients were randomly allocated to: ‘fast track’ open verum homeopathy, ‘fast track’ double-blind verum homeopathy, ‘fast track’ double-blind placebo homeopathy or waiting list control.

Main outcome measures: One hundred millimeter visual analogue scale of overall symptom severity; 10 point digital scores of sleep, itching, skin condition; weekly 5-point Likert scale of topical steroid use; Dermatology Life Quality Index at entry and completion.

Results: Recruitment was below target, but the study was acceptable to staff and feasible. Blinded patients were more likely to withdraw (P=0.021, χ² test). After correction for baseline differences and multiple comparisons, no outcome measure showed statistically significant between group differences. Blindness appeared to have a negative effect, but this was confounded by differential withdrawal.

Conclusions: A definitive trial of this design is unlikely to discriminate the relative contributions of the non-specific and specific effects to the outcome of homeopathic treatment of dermatitis, because of patient preference issues.

Keywords

Specific effects - non-specific effects - dermatitis - randomised controlled trial - placebo control waiting list control

• References

• 1 Weatherley-Jones E., Thompson E.A., Thomas K.J. The placebo-controlled trial as a test of complementary and alternative medicine: observations from research experience of individualised homeopathic treatment. Homp 2004; 93: 186-189.
• 2 Williams H.C., Burney P.G.J., Pembroke A.C., Hay R.J. The UK working party's diagnostic criteria for atopic dermatitis III Independent hospital validation. Br J Dermatol 1994; 131: 406-414.
• 3 Finlay A.Y., Khan G.K. Dermatology Life Quality Index (DLQI)—a simple practical measure for routine clinical use. Clin Exp Dermatol 1994; 19: 210-216.
• 4 Vickers A.J., Altman D.G. Analysing controlled trials with baseline and follow-up measurements. Br Med J 2001; 323: 1123-1124.
• 5 Thompson E., Barron S., Spence D. A preliminary audit investigating remedy reactions including adverse events in routine homeopathic practice. Homp 2004; 93: 203-209.
• 6 Siebenwirth J. A randomized, placebo-controlled double blind study testing the effectiveness of classical homeopathic therapy of atopic dermatitis. In Conference Proceedings: Future Directions and Current Issues of Research in Homeopathy. Samueli Institute, Freiburg, 2002, pp 79–90.
• 7 Kleijnen J., de Craen A., van Everdingen J., Krol L. Placebo effects in double-blind trials: a review of interactions with medications. Lancet 1994; 344: 1347-1349.
• 8 Kirsch I., Weixel L.J. Double-blind versus deceptive administration of a placebo. Behav Neurosci 1988; 102: 319-323.
• 9 Kirsch I., Rosadino M.J. Double-blind studies with informed consent yield externally valid results. Psychopharmacology 1993; 110: 437-442.
• 10 Walach H., Schmidt S., Dirhold T., Nosch S. The effects of a caffeine placebo and suggestion on blood pressure, heart rate, well-being and cognitive performance. Int J Psychophysiol 2002; 43: 247-260.
• 11 Mikalsen A., Bertelsen B., Flaten M.A. Effects of caffeine, caffeine-associated stimuli, and caffeine-related information on physiological and psychological arousal. Psychopharmacology (Berl) 2001; 157: 373-380.