The impact of trauma exposure and post-traumatic stress disorder on healthcare utilization among primary care patients

Background: Trauma exposure and post-traumatic stress disorder (PTSD) increase healthcare utilization in veterans, but their impact on utilization in other populations is uncertain. Objectives: To examine the association of trauma exposure and PTSD with healthcare utilization, in civilian primary care patients. Research Design: Cross-sectional study. Subjects: English speaking patients at an academic, urban primary care clinic. Measures: Trauma exposure and current PTSD diagnoses were obtained from the Composite International Diagnostic Interview. Outcomes were nonmental health outpatient and emergency department visits, hospitalizations, and mental health outpatient visits in the prior year from an electronic medical record. Analyses included bivariate unadjusted and multivariable Poisson regressions adjusted for age, gender, income, substance dependence, depression, and comorbidities. Results: Among 592 subjects, 80% had >= 1 trauma exposure and 22% had current PTSD. In adjusted regressions, subjects with trauma exposure had more mental health visits [incidence rate ratio (IRR), 3.9; 95% confidence interval (CI), 1.1-14.1] but no other increased utilization. After adjusting for PTSD, this effect of trauma exposure was attenuated (IRR, 3.2; 95% CI, 0.9-11.7). Subjects with PTSD had more hospitalizations (IRR, 2.2; 95% CI, 1.4-3.7), more hospital nights (IRR, 2.6; 95% CI, 1.4-5.0), and more mental health visits (IRR, 2.2; 95% CI, 1.1-4.1) but no increase in outpatient and emergency department visits. Conclusions: PTSD is associated with more hospitalizations, longer hospitalizations, and greater mental healthcare utilization in urban primary care patients. Although trauma exposure is independently associated with greater mental healthcare utilization, PTSD mediates a portion of this association.