Focus on Alternative and Complementary Therapies
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Focus Alternat Complement Ther©2005 Pharmaceutical Press
Focus Altern Complement Ther 2003; 8: 501
The so-called placebo effect includes, underlying other factors, psycho-sociological aspects. The aim of this study was to evaluate whether and to what extent this leads to different effects between cultures in placebo treated patients.
Individual data from the placebo groups of 68 RCTs (nine multinational) were analysed regarding efficacy and safety parameters. All trials were conducted by Bayer AG, Germany, and dealt with (a) metrifonate in Alzheimer’s disease (AD), (b) nimodipine in sub-arachnoidal haemorrhage, or (c) acarbose in diabetes. All analyses were adjusted for duration and severity of the disease and other potential confounders.
(a) For the ADAS-Cog (AD subscale), the deterioration under placebo when compared with baseline in German patients was larger than in Austria (difference after 182 days: 3.2 score points, 95% CI 0.8–5.7, P = 0.0097) and the UK (2.9 points, 95% CI 0.3–5.5, P = 0.0267). (b) Large inter-country variations of changes in the Barthel score can be found (P < 0.001): adjusted for baseline Australian placebo-treated patients had the best, and South African and Singaporean patients the poorest outcome, (c) Gastrointestinal adverse events under placebo ranged from 7.7% (Greece) to 37.0% (Litavia) within the first 30 days.
The observed large differences between countries may be associated with different levels of health care (e.g. in subarachnoidal haemorrhages) or different reporting habits (e.g. in safety aspects). Nevertheless, a high variability between countries and cultures could be observed for the placebo-effect size and may be of relevance for multinational clinical trials.
