Pathways to Outcomes of Quality Improvement in Depression

Key aims: Pathways aims to estimate how exposure to short-term quality improvement programs through primary care practices affects long-run economic consequences; to estimate the long-run economic consequences to individuals of recovery from depression; and to test the usefulness of modeling these consequences in other intervention studies by comparing the direct and indirect (through remission) estimates of the effects of the quality improvement programs utilized in Partners in Care.

Methods: Participants in the Partners in Care study were interviewed by telephone at 57 months to obtain information on their economic outcomes (employment, labor force participation, income and wealth) as well as to obtain limited information on clinical outcomes (i.e., to examine whether long-term remission may be a mediating factor for the impact of short-term remission on long-term economic outcomes). Using these data, intent-to-treat analyses of the effects of quality improvement interventions and instrumental variables analysis of the effects of remission on those outcomes are being conducted. The study is both a longitudinal cohort study (for observational analyses) and a long-term outcome study of a randomized dissemination trial (for experimental analyses).

Significance: Pathways is among the first to examine how exposure to a short-term quality improvement intervention for depression treatment affects patients' long-term economic outcomes. It is among the first to examine how remission from depression affects patients' long-term economic outcomes. The unique design provides a range of methods to analyze the study's aims, including intent-to-treat analyses of quality improvement intervention effects, and single-equation and instrumental variables analyses of the effects of remission on long-term outcomes.

Impact: The study helps inform policy towards depression treatment in at least two ways. First, it provides evidence on the long-term effects of depression remission on economic outcomes. The estimates provided can be combined with information from short-term randomized treatment or quality-improvement trials to evaluate short- or long-term economic outcomes. Second, the research provides evidence of the possible effects of particular quality improvement intervention to improve depression care. The improvements in clinical status and economic outcomes due to the Partners in Care intervention in the first two years of follow-up suggest that long-term effects of the intervention are possible. The analyses from this study provide additional information on the scope and duration of outcomes associated with quality improvement efforts implemented under naturalistic conditions.

Current status: Pathways is in the second year of a 3-year grant. Data collection is complete, analyses and publication efforts are ongoing.