Dose-response relationship between depressive symptoms and hospital readmission.

Background: Evidence suggests depression increases hospital readmission risk.

Objective: Determine whether depressive symptoms are associated with unplanned readmission within 30 days of discharge of general medical patients.

Design: Secondary analysis of the Project Re-Engineered Discharge (RED) randomized controlled trials.

Setting: Urban academic safety-net hospital.

Patients: A total of 1418 hospitalized adult English-speaking patients.

Intervention: The 9-Item Patient Health Questionnaire (PHQ-9) was used to screen patients for depressive symptoms.

Measurements: Hospital readmission within 30 days of discharge. Poisson regression was used to control for confounding variables.

Results: There were 225 (16%) patients who screened positive for mild depressive symptoms (5 ≤PHQ-9 ≤ 9) and 336 (24%) for moderate or severe depressive symptoms (PHQ-9 ≥ 10). After controlling for confounders, a higher rate of readmission was observed in subjects with mild depressive symptoms compared to subjects with PHQ-9 <5, incidence rate ratio (IRR) 1.49 (95% confidence interval [CI]: 1.11-2.00). The adjusted IRR of readmission for those with moderate-to-severe symptoms was 1.96 (95% CI: 1.51-2.49) compared to those with no depression.

Conclusions: Screening positive for mild and moderate-to-severe depressive symptoms during a hospitalization on a general medical service is associated with an increased dose-dependent readmission rate within 30 days of discharge in an urban, academic, safety-net hospital. Further research is needed to determine whether treatments targeting the reduction of depressive symptoms reduce the risk of readmission.