Methodology of clinical trials in dementia. Part II: Future trials— Recommendations

Abstract

In a large review of the 102 clinical trials in dementia (Yesavage et al., 1979) 53 of the clinical trials were considered to be ‘well-designed’ studies (see chapter 14). Of these 53 trials, 48 were positive. It is therefore surprising that, despite these apparently satisfactory figures, the number of controlled trials in dementia has considerably decreased since 1975. Furthermore the medical community at large has not accepted the above-mentioned results as real proof of advancement in the treatment of dementia. The reasons for this have been summarised by Hughes et al. (1976): Because of the small magnitude of the improvement to be expected and the absence of indications of long-term benefits, it would seem that at present vasodilators are of minor clinical value in the treatment of dementia. Further studies with better methodologies and longer follow-up periods … may lead to more favourable conclusions.