Diabetes incidence and prevalence in Hong Kong during 2007-13

Abstract

Purpose To estimate the incidence and prevalence of diabetes in Hong Kong using the Hospital Authority’s Clinical Management System (CMS) database. Setting Hong Kong has a mixed public-private health care economy. The Hospital Authority provides public sector services including hospitals, specialist outpatient clinics and general outpatient clinics (primary care). Hospital Authority services accounts for the majority of inpatient care (90% total bed-days), 50% of specialist outpatient care, and 30% of general outpatient services. Methods CMS data comprised of 6.1 million unique patient records during the period Jan 1, 2006 to Dec 31, 2013 inclusive. Ascertainment of diabetes was based on WHO 2011 guidelines on oral glucose tolerance test (OGTT), fasting glucose and glycated haemoglobin; American Diabetes Association criterion of random plasma glucose in two separate months; and diagnosis coding for diabetes (International Classification of Disease and International Classification of Primary Care). Patients were counted as an incident case in the year of diagnosis, and then excluded from the numerator and denominator for subsequent years. Confidence intervals for incidence and prevalence were estimated using Poisson and binomial distributions respectively. Thematic Household Survey data was used to estimate the proportion of patients with diabetes who did not use public sector (Hospital Authority) services. Results Among adults aged 20 years and over, the crude incidence of diabetes remained stable from 2007 to 2013, ranging from 9.0 per 1,000 person-years (95% CI: 8.9, 9.1) to 9.5 per 1,000 person-years (95% CI: 9.4, 9.6). Age and sex-standardized incidence ranged from 9.1 (95% CI: 9.1, 9.2) to 9.7 (95% CI: 9.7, 9.8) per 1,000 person-years from 2008 to 2013. The crude prevalence of diabetes among adults aged 20 years and over increased from 5.0% (95% CI: 5.0, 5.0) in 2007 to 8.2% (95% CI: 8.2, 8.2) in 2013. Age and sex-standardized prevalence increased slightly from 5.6% (95% CI: 5.6, 5.7) to 8.2% (95% CI: 8.1, 8.2). Adjusting for patients with diabetes outside the public sector, the prevalence in 2013 was 9.4% and the incidence in 2013 was 10.8 per 1,000 person-years. Incidence and prevalence increased with age. During the period 2007 to 2013, the incidence rates within the age- and sex-specific strata were stable. Conclusion Similar to highly developed Western and Asian countries, the incidence rate in Hong Kong appears to have stabilised. The overall prevalence of diabetes has continued to rise.