Is the clinical trial evidence about new drugs statistically adequate?

The statistical adequacy of all papers published in the period 1976-80 describing clinical trials of five non-steroidal anti-inflammatory and two analgesic drugs introduced into the UK market in 1978 and 1979 has been assessed using a checklist of simple criteria. Most trials were reported to be randomised and double-blind. Trial designs were less satisfactory in other important respects; the sample size of most trials was inadequate to demonstrate superiority of the new drug compared with an active control therapy. The period of treatment assessment was short in view of the likelihood of prolonged prescription of drugs in these classes. It is suggested that licensing authorities should demand higher standards of clinical trial evidence offered in support of new drugs.