Evidence-based rehabilitation: The case for and against constraint-induced movement therapy

Along with much of psychiatry and complementary therapies, the field of rehabilitation lacks the solid foundation of empirically derived data demonstrating the efficacy of key interventions. Rehabilitation research lags behind drug development, in which at least one multicenter trial with adequate statistical power is required before regulatory approval is granted. Rehabilitation even lags behind many surgical fields, where many expensive or commonly performed procedures are eventually put to the test of a randomized controlled trial. Many widely performed procedures, hailed by their advocates as so obviously effective that randomized controlled trials were not needed or were even unethical, litter the medical literature. Once performed by the thousand, procedures such as extracranial-intracranial bypass for stroke prevention and irrigation of knees for degenerative joint disease are now abandoned because objective clinical trials showed no benefit to the participants. Rehabilitation has several features that make it peculiarly susceptible to the acceptance of treatments with little or no direct evidence of efficacy. First is the lack of obvious and catastrophic clinical failure to force rehabilitationists to test and refine ideas and treatments. While rehabilitation probably does reduce long-term morbidity and mortality, patients do not obviously and immediately die from bad rehabilitation, as they might from poor surgical techniques or ineffective drugs. Thus, rehabilitationists do not face the same discipline of clinical failure that many other clinicians face. Second, treatment often has no hard end points, such as survival time in oncology trials or the counting of seizure events in epilepsy trials. Since rehabilitationists strive to promote independence, quality of life, and other difficult-to-measure goals, development of clinical trials has been hampered by difficulties in methodology— how do we measure what we claim to be improving? A third problem is that the nature of most rehabilitation interventions makes standardizing the treatment intervention difficult; a behavioral treatment such as a motor therapy or a memory-retraining strategy is much more operator-dependent than simply giving the patient a drug or device. Finally, rehabilitation lacks the type of industry interest that drives the development of new drugs and devices. Though there is no shortage of for-profit rehabilitation enterprises, they spend miniscule bits of their revenue on research and development. This is a striking contrast to the pharmaceutical and medical-device companies that view new treatments as their lifeblood and spend accordingly. Constraint-induced movement therapy (CIMT) is a rehabilitation treatment with some promise and is Alexander W. Dromerick, MD Associate Professor of Neurology and Occupational Therapy Washington University School of Medicine St. Louis, Missouri