Prevalence of hypertension and diabetes in Finland by different data sources

Abstract

Abstract Background Population level information on the prevalence of hypertension and diabetes is needed to support planning and evaluation of preventive activities and care. Population based health examination surveys (HES) can provide valid information, but they are time consuming and expensive. Administrative registers on hospitalizations and out-patient visits could provide information faster and at less cost. The aim of this study is to estimate how comparable prevalence estimates of type 2 diabetes (T2D), hypertension and their combination are based on data from the Finnish national health examination survey (FinHealth 2017) and data from administrative hospital and primary care registers in Finland. Methods Survey data were linked to care registers using personal identity codes. Survey based hypertension was defined as SBP≥140 mmHg or DBP≥90 mmHg or self-reported use of antihypertensive medications; and T2D as HbA1c ≥48 mmol/mol or self-reported us of diabetes medications. Corresponding indicators from care registers were: hypertension and T2D as a reason for care or visit or having received prescription for diabetes medication (using ICD-10, ICPC and ATC codes). Results For hypertension, survey data provided the prevalence of 43 % while only 12 % of individuals were identified as hypertensives in the register data. The prevalence of T2D was 9 % in both data sources. The prevalence of having both hypertension and T2D was 7 % based on survey data and 3 % based on register data. Agreement between survey and register data was lower for hypertension (Cohen’s kappa 0.23) than for T2D (0.84). Conclusions Register data provided lower prevalence for hypertension than the survey data. For diabetes, similar prevalences were observed. As there are limitations in the coverage of register data more reliable population level information can be obtained from HES. Key messages Health examination surveys cover persons with undiagnosed problems and conditions omitted in national registers. Hypertension and T2D should be monitored with both register and survey data.