Somatization and health anxiety as predictors of health care use

Objective: To assess whether the number of somatic symptoms and health anxiety are independent predictors of future health care use after adjusting for confounders. Methods: In a random sample of the adult UK population, questionnaires assessed the number of somatic symptoms (Somatic Symptom Inventory), health anxiety (Whiteley Index), anxiety/depression (Hospital Anxiety and Depression Scale), the number of physical illnesses and demographic variables. The number of consultations in primary care was obtained from medical records for 1 year before and after questionnaire assessment, and negative binomial regression analyses identified predictors of consultation rate. Results: The sample included 961 participants (58.0% response) with complete medical record data for 609 participants. After adjustment for consultation rate in the prior year, the predictors of subsequent consultation rate in primary care were the number of physical illnesses, off work through illness, Whiteley Index (incidence rate ratio [IRR] = 1.22, 95% confidence interval [CI] = 1.09-1.35), and the Whiteley Index-by-Somatic Symptom Inventory interaction term. Reported physical abuse predicted an increased consultation rate in women (IRR = 2.30, 95% CI = 1.08-4.90) but a reduced rate in men (IRR = 0.43, 95% CI = 0.22-0.84), interaction p = 0.003. Conclusions: These data raise the possibility that both increased health anxiety and number of bothersome somatic symptoms predict frequent medical consultations. A more complex model of predicting future health care use is needed than has been studied previously, which is potentially relevant to the current discussions of the proposed DSM-V and International Classification of Diseases, 11th Revision, diagnostic guidelines regarding complex somatic symptom disorders.