Impact of socioeconomic status on depression clinical outcomes at six months in a Midwestern, United States community

Introduction: Lower socioeconomic status (SES) has been associated with poor healthcare outcomes in depression. However, reliable individual-level SES data rarely exists for clinical research. The HOUSES index relies on publicly available data allowing for evaluation of individual-level SES on patient outcomes.

Hypothesis: Primary care patients with depression within the lower SES quartile (Quartile 1 vs. Quartile 4, of the HOUSES index) would experience worse clinical outcomes of their symptoms six months after diagnosis.

Study design: A retrospective cohort study which followed 4313 adult primary care patients that were diagnosed with depression during the study period of 2008-2015. The outcome measures were the six month PHQ-9 scores.

Results: At six months, a higher HOUSES quartile was associated with greater odds of remission of depressive symptoms (RDS) and lower odds of persistent depressive symptoms (PDS), after controlling for covariates. Patients in Quartile 4 had 27% more likelihood of RDS and a 24% lower likelihood of PDS at six months compared to a Quartile 1 patient.

Limitations: As a retrospective study only can observe associations but not causation. Only one institution participated and not all treatments were readily available, limiting the generalizability of these findings.

Conclusions: Lower SES as demonstrated by a lower HOUSES quartile (Quartile 1 versus 4) was associated with lower odds of RDS and increased odds of PDS at six months. HOUSES index is a useful tool for identifying patients at risk for worse clinical outcomes and may help health care systems plan resource allocation for depression care.