Designing clinical trials for the treatment of delirium

Abstract

There is a large body of empirical evidence for the usefulness of pharmacological treatment of delirium though there is a relative dearth of double-blind randomized clinical trials and few that are placebo controlled. There are no registration quality double-blind, randomized, placebo-controlled trials that evaluate efficacy and safety, nor is there a regulatory body in any country that has approved a drug with an indication to treat delirium. Reasons include inadequate training for design and implementation of clinical trials, too few patients at a given research site to adequately power a study, confounding variables such as dementia, multifactorial underlying etiologies that are difficult to control, inadequate understanding of the neuropathophysiology of delirium that could theoretically guide a choice of drugs, referral populations where the primary physician may not be the one interested in pursuing the research, confounding factors for attribution of safety signals, and lack of funding for an adequately powered trial outside of the pharmaceutical industry. This article provides basic information aimed at educating physicians and other clinicians about design and implementation considerations to conduct an adequately powered double-blind, randomized placebo-controlled clinical trial to evaluate a drug's efficacy in delirium.