['To report the rates of medical claims for sense of smell disturbance (SD) and their association with diseases and medications in a managed care population.', 'Descriptive determination of demographics, prevalence, and incidence of SD and case-control analysis of risk factors. Preselected drug and disease groups were entered into a stepwise regression model to determine risk factors for SD.', 'Managed care organizations in the United States.', "Patients identified through medical claims within IMS Health's LifeLink: Integrated Claims Solution (IMS) and i3 Magnifi Private Managed Care Organizations (MCO) medical insurance databases for 3-year observation periods.", 'Prevalence and incidence of smell disturbance; adjusted odds ratios and 95% confidence intervals (CIs) of associated conditions and medications.', 'The mean annual prevalence rate of SD was 26.2 per 100 000 for IMS (95% CI, 23.1-29.6) and 17.2 per 100 000 for MCO (95% CI, 15.6-18.7). The mean annual incidence per 100 000 was 26.3 for IMS (95% CI, 23.1-29.8) and 15.9 for MCO (95% CI, 14.5-17.5). The 5 strongest risk factors for SD were chronic sinusitis, oropharyngeal inflammatory disorders, other upper respiratory tract disease excluding sinusitis, cerebrovascular disease, and systemic viral disease. The regression model also retained 3 drug groups (corticosteroids, calcium channel blockers, and nasal and/or sinus products) among the significant risk factors for the presence of SD.'] Does epidemiologic study of smell disturbance in 2 medical insurance claim populations?