Do secondary conditions explain the relationship between depression and health care cost in women with physical disabilities?

OBJECTIVE

To examine the influence of depression on health care utilization and costs among women with disabilities and to determine whether the severity of other secondary health conditions affects this association.

DESIGN

A time series of 7 interviews over a 1-year period.

SETTING

Large, southern metropolitan area.

PARTICIPANTS

Community-dwelling women (N=349) with a self-identified diagnosis of a physical disability.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Primary disability, secondary health conditions (Health Conditions Checklist), depressive symptoms (Beck Depression Inventory-Second Edition), and health care utilization (based on the Health and Social Service Utilization Questionnaire and the Stanford Health Assessment Questionnaire). We estimated health care costs using standardized criteria and published average costs.

RESULTS

Outpatient and emergency department health care utilization and overall costs were higher in women with depressive symptoms and increased with the frequency and severity of the symptoms. Depressive symptoms were highly correlated with the severity of secondary health conditions. Adjusting for demographics and primary disability, both the presence and severity of depressive symptoms were associated with significantly higher health care costs. However, secondary health condition severity explained the association between depressive symptoms and cost; it also substantially increased the variance in cost that was explained by the multivariate models.

CONCLUSIONS

Secondary health conditions are significantly associated with depressive symptoms and higher health care costs, with secondary health conditions accounting for the association between depressive symptoms and costs. This association suggests that effective management of secondary health conditions may help reduce both depressive symptomatology and health care costs.