Somatoform disorder in primary care: The influence of co-morbidity with anxiety and depression on health care utilization.

RATIONALE, AIMS, AND OBJECTIVES: Patients with somatoform disorders are frequent attenders in primary and secondary care. While co-morbid mental disorders, especially depression and anxiety, are frequently present, there is controversy on whether mental co-morbidity leads to higher health care utilization (HCU). The present paper investigates the influence of co-morbid depressive and anxiety disorders on primary, specialized somatic and mental HCU in primary care patients with somatoform disorders. Additionally, we investigated the predictive value of self-rated health and illness perception on HCU.

METHODS: Patients in 19 primary care practices were screened with the Patient Health Questionnaire, and patients at high risk for somatoform disorders were assessed using the Composite International Diagnostic Interview. N = 71 patients with somatoform disorders were analysed. We analysed whether having one vs two co-morbidities (depression and/or anxiety), self-rated health, and illness perception were predictors for primary, specialized somatic and mental HCU using binominal and hierarchical regression analyses.

RESULTS: Having both co-morbid depressive and anxiety disorder predicted higher primary HCU (IRR = 1.96, 95% CI, 1.30-2.93), and increased the odds of being in mental health care (OR = 5.16, 95% CI, 1.10-24.20), while only one co-morbidity did not. No differences were found for specialized somatic HCU. Illness perception and self-rated health did not predict HCU.

CONCLUSION: Not a single but only the presence of multiple co-morbidities predicts primary and mental HCU in patients with somatoform disorder. Health care utilization might be essentially influenced by the associated psychological distress, which should be considered in treatment.