Prevalence of diabetes in patients with schizophrenia in Taiwan: A population-based National Health Insurance study

Objective: We conducted this study to investigate the prevalence and correlates of diabetes in patients with schizophrenia in Taiwan. Methods: The National Health Research Institute provided a database of 1,000,000 random subjects for study. We obtained a random sample aged 18 years and over of 766,427 subjects in 2005. Those study subjects who had at least one service claim during this year for either ambulatory or inpatient care, with a primary diagnosis of schizophrenia or with a prescription for treatment of diabetes, were identified. Results: The prevalence of diabetes in patients with schizophrenia was higher than in the general population (7.90% vs. 5.57%, odds ratio [OR], 1.81; 95% confidence interval [CI], 1.61-2.03). Compared with the general population, patients with schizophrenia revealed a higher prevalence of diabetes in all age groups, except age 70 or more years; among females (10.30% vs. 5.42%, p<0.001), and males (5.93% vs. 5.73%, p<0.001): among all insurance amount groups; among those living in the northern (7.56% vs. 4.89%, p<0.001), central (8.26% vs. 5.61%, p<0.001), southern regions (8.45% vs. 6.62%, p<0.001); and among residents living in urban (8.18% vs. 5.19%, p<0.001) and rural areas (7.99% vs. 6.15%, p<0.001). Conclusions: Patients with schizophrenia had a much higher prevalence of diabetes in younger adult age groups and in females than in the general population, a finding that deserves further biological and psychosocial study in the future. (C) 2009 Elsevier B.V. All rights reserved.