The use of clinical trials in comparative effectiveness research on mental health.

OBJECTIVES: A large body of comparative effectiveness research (CER) focuses on the use of observational and quasi-experimental approaches. We sought to examine the use of clinical trials as a tool for CER, particularly in mental health.

STUDY DESIGN AND SETTING: Examination of three ongoing randomized clinical trials in psychiatry addressing issues that would pose difficulties for nonexperimental CER methods.

RESULTS: Existing statistical approaches to nonexperimental data appear insufficient to compensate for biases that may arise when the pattern of missing data cannot be properly modeled such as when there are no standards for treatment, when affected populations have limited access to treatment, or when there are high rates of treatment dropout.

CONCLUSION: Clinical trials should retain an important role in CER, particularly in cases of high disorder prevalence, large expected effect sizes, difficult-to-reach populations, or when examining sequential treatments or stepped-care algorithms. Progress in CER on mental health will require careful consideration of appropriate selection between clinical trials and nonexperimental designs and on allocation of research resources to optimally inform key treatment decisions for each patient.