LONGITUDINAL-STUDY OF DEPRESSION AND HEALTH-SERVICES USE AMONG ELDERLY PRIMARY-CARE PATIENTS

OBJECTIVE: To describe the prevalence and 9-month incidence of depress ive symptoms among a cohort of elderly primary care patients and to de termine whether different patterns of depression are associated with d ifferent patterns of health services use. DESIGN: Prospective study of depressive symptoms as measured by the Center for Epidemiologic Studi es Depression (CES-D) scale and identification of patients' outpatient health services use through an electronic medical record system. SETT ING: An academic primary care group practice at an urban ambulatory ca re clinic. PATIENTS/PARTICIPANTS: 1711 patients aged 60 and older who completed the CES-D at baseline and 9 months later; 935 of these patie nts also completed the CES-D at 6 months. MEASUREMENT AND MAIN RESULTS : The prevalence of significant symptoms of depression (CES-D greater than or equal to 16) was 17.1% at baseline and 18.8% at 9 months; 26.8 % of patients exceeded the threshold on the CES-D either at baseline o r 9 months, and the 9-month incidence was 11.7%. Among the patients re -interviewed at both 6 and 9 months, the 6-month incidence was 12%, an d the incidence between the 6- and 9-month assessments was 10%. Of the 292 patients with depression at baseline, 140 (47.6%) remained depres sed at the 9-month follow-up. Baseline and 6-month CES-D score, in add ition to perceived health at 6 months, explained 45% of the variance i n the 9-month CES-D score. Patients above the threshold on the CES-D a t any time were more likely to rate their health as fair or poor (69.8 % vs 43.7%) and more likely to have an emergency room visit (40.4% vs 29.4%). These patients also had 38% more outpatient visits (7.7 vs 5.6 ) and 61% higher total outpatient charges ($1209 vs $751) than patient s who never exceeded the CES-D threshold over the 9-month window (all P values < 0.01). CONCLUSIONS: Depressive symptoms were frequent and o ften persistent in this patient population. We identified patterns of oscillating severity of symptoms within individuals but relatively sta ble incidence and prevalence rates over a 9-month period. Patients who exceeded the threshold on the CES-D at any time during the study had significantly greater health services use and poorer perceived health.