Generalizability of findings from efficacy trials for chronic depression: an analysis of eligibility criteria.

OBJECTIVES: Concerns have been raised that the rigorous eligibility criteria used to select patients for randomized controlled trials (RCTs) limit the generalizability of trial findings. The objectives of this study were to identify commonly used eligibility criteria in RCTs for chronic depression, to examine whether these criteria are met by patients with chronic depression who are in routine care, and to identify differences between patients who would and would not meet RCT criteria. METHODS: Thirteen eligibility criteria were extracted from eight RCTs of combined psychotherapeutic and pharmacological interventions for patients with chronic depression. These criteria were then applied to a sample of patients with chronic depression receiving care in one of ten German hospitals (N=231). Demographic, clinical, and treatment characteristics of those who met the RCT criteria and those who did not were compared in univariate and multivariate analyses. RESULTS: Only 25% of the 231 inpatients met all RCT eligibility criteria. Patients were ineligible mainly because of suicide risk, low severity of depression at admission, and concurrent psychiatric or somatic disorders. No statistically significant differences were found between those who met the criteria and those who did not in demographic characteristics, length of inpatient stay, treatment outcome, and efficacy of certain antidepressants, except that slightly more patients meeting RCT criteria received selective serotonin reuptake inhibitors. CONCLUSIONS: Findings suggest that the generalizability of RCT findings to routine health care is less limited than frequently supposed.