[Comorbidity and related costs as a burden in the treatment of outpatients with depressive disorders in a primary care setting]. / Comorbilidad y coste ambulatorio asociado a los pacientes con trastornos depresivos en un ámbito poblacional.

ABSTRACT

OBJECTIVE: To study the impact of depressive disorders (DD) on health care expenditure and to measure associated comorbidity in patients in primary care settings (PCS) under normal clinical practice conditions. METHOD: A retrospective cohort study was carried out. The study cohort consisted of outpatients aged over 14 years of age with an established diagnosis of DD (ICPC; P76) treated in a PC health centre during 2004. A comparative cohort was formed with the remaining outpatients without DD, treated in that health centre. Main factors for calculation were age, gender, history/comorbidity and health resource use and the corresponding outpatient costs; drugs, diagnostic tests, visits to specialists and PC physicians. Multiple logistic regression analysis and ANCOVA models were used in order to adjust costs and comorbidities between the cohorts of patients. RESULTS: A total of 64,072 subjects were assessed; 6,592 patients with DD [10.3% (CI 8.2-12.4%), 74.5% (CI 73.4%-75.6%) females]. DD outpatients displayed a higher number of episodes of comorbidities/year (mean +/- SD; 7.4 +/- 4.3 vs. 4.7 +/- 3.3, p < 0.0001) and global medical visits/patient/year (12.0 +/- 9.3 vs. 7.4 +/- 7.6, p < 0.0001). The main comorbidities associated to DD were neurological disorders [Odds ratio (95% CI); 2.1 (CI 1.5-2.6), p < 0.0001], alcoholism [1.6 (CI 1.3-1.9), p < 0.0001] and malignancies [1.3 (CI 1.1-1.5), p < 0.0001]. DD were associated with significantly higher adjusted total costs; 1,083.8 euro (SEM; 8.4 euro) vs. 684.1 euro (3.4 euro), p < 0.0001. Higher costs were displayed for elderly patients. Sixty-two percent of the total cost was related to drugs. CONCLUSIONS: Prevalence of DD was higher, particularly in women. Following adjustment in accordance with comorbidity, age and sex, DD outpatients used more health care resources and implied higher costs. Higher costs were associated with age.