The Quality Improvement for Depression Collaboration: general analytic strategies for a coordinated study of quality improvement in depression care

It is difficult to evaluate the promise of primary care quality-improvement interventions for depression because published studies have evaluated dive rse interventions by using different research designs in dissimilar populat ions. Preplanned meta-analysis provides an alternative to derive more preci se and generalizable estimates of intervention effects; however, this appro ach requires the resolution of analytic challenges resulting from design di fferences that threaten internal and external validity. This paper describe s the four-project Quality Improvement for Depression (QID) collaboration s pecifically designed for preplanned meta-analysis of intervention effects o n outcomes. This paper summarizes the interventions the four projects teste d, characterizes commonalities and heterogeneity in the research designs us ed to evaluate these interventions, and discusses the implications of this heterogeneity for preplanned meta-analysis. (C) 2001 Elsevier Science Inc. All rights reserved.