PREVALENCE OF RESISTANT HYPERTENSION BY ADHERENCE CRITERIA AND THE RELATED FACTORS IN KOREAN NATIONAL HEALTH INSURANCE SERVICE - NATIONAL SAMPLE COHORT (NHIS-NSC)

Abstract

Objective: Resistant hypertension (RH) is an important challenge in hypertension management. And adherence was reported to be very important when to diagnose a RH. There are few studies to report the prevalence of RH by reflecting the aspect of adherence. Insurance claim database has advantage to reflect the information on the prescription and its duration.

Design and method: In Korean National Health Insurance Service – National Sample Cohort (NHIS-NSC), prescription duration and the pill counts for (AHM) were analyzed per prescription and per person. Among 7780 subjects taking at least one AHM > 30 days per year, 2370 subjects with proportion of days covered (PDC) > 0.8 (at least 300 days per year) were analyzed. RH prescription for a person was defined as pill count of 3 including diuretics or as 4 or more pill count.

Results: Subjects taking three drugs including diuretics 141 (6.0%) and subjects taking 4 or more drugs were 21(0.9%). Among 141 subjects, BPs in 63.8% (n = 90) were not controlled below 140/90 mmHg. So the prevalence of RH was 4.7% (111/2370). BMI was significantly different between groups (25.2 ± 3.0 vs 26.3 ± 3.6 kg/m2, p = 0.0038). In stepwise multiple logistic regression analysis, socioeconomic status was significant (odds ratio, 1.613 [95% CI:1.086∼2.397], p = 0.0179) and diabetes (odds ratio, 1.506, p = 0.0567) and moderate physical activity (odds ratio, 1.526, p = 0.0504) were marginal in significance. When the pill number was counted when AHM was prescribed for 30 or more days at least, the prevalence of RH was 9.4% (728/7780).

Conclusions: By using health insurance claim data, the prevalence of RH in Korea was 4.7%. And the house income was the significant factor for RH. Diabetes and moderate physical activity were the associated factors with borderline significance for RH. Without adherence criteria the prevalence of RH can be overestimated.