Risk Factors and the Usual Source of Care on Non-Adherence to Antihypertensive Drugs in Immigrants with Hypertension

Hyemin Cho; Sohyun Jeong; Cinoo Kang; Hee-Jin Kang; Suhyun Jang; Sunmee Jang

doi:10.2147/PPA.S269008

Risk Factors and the Usual Source of Care on Non-Adherence to Antihypertensive Drugs in Immigrants with Hypertension

Patient Prefer Adherence. 2020 Nov 2:14:2123-2133. doi: 10.2147/PPA.S269008. eCollection 2020.

Authors

Hyemin Cho^#¹, Sohyun Jeong^#^{2

3}, Cinoo Kang⁴, Hee-Jin Kang¹, Suhyun Jang¹, Sunmee Jang¹

Affiliations

¹ College of Pharmacy and Gachon Institute of Pharmaceutical Sciences, Gachon University, Incheon, Republic of Korea.
² Marcus Institute for Aging Research, Hebrew SeniorLife, Boston, MA, USA.
³ Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA.
⁴ Department of Biostatics and Epidemiology, Graduate School of Public Health, Seoul National University, Seoul, Republic of Korea.

^# Contributed equally.

Abstract

Background: Immigrants are vulnerable to suboptimal health care utilization including non-adherence of medication use. Thus, we aimed to identify the potential risk factors of non-adherence and evaluate whether utilizing a usual source of care was associated with medication adherence in immigrants.

Methods: We utilized the Korea National Health Insurance Claims Database between 2012 and 2015. Cases were immigrants who had antihypertensive prescriptions at the time of hypertension diagnosis in 2012. Controls were native-born Koreans with hypertension who were 1:1 matched to immigrants by age, sex, and Charlson comorbidity index. We used the medication possession ratio for three years to assess the adherence to antihypertensive drugs. The likelihood of non-adherence was evaluated between cases and controls by multivariate linear regression models stratified by age, sex, and number of clinic visits. We assessed the potential risk factors of non-adherence in immigrants by multivariate linear regression and logistic regression models, respectively.

Results: In total, 4114 immigrants and 4114 matched native-born Koreans with hypertension were included. The mean MPR was significantly lower in immigrants (56% vs 70%, p<0.0001). Immigrants showed almost two times the level of non-adherence as native-born Koreans (odds ratio [OR], 2.01; 95% confidence interval [CI], 1.83-2.21). Stratified analyses on non-adherence presented the highest non-adherence (2.28 times) in immigrants in the younger group (30-49 years old) and the lowest non-adherence in immigrants in 65 and old group where the risk was 1.69 times higher than native Korean with the same age. The absence of a usual source of care significantly increased medication non-adherence by 1.31 to 1.58 times among immigrants.

Conclusion: When the number of visited clinics increased, the degree of non-adherence increased consistently. Therefore, the systematization of registering with primary care (a usual source of care) might be a modifiable health care strategy to improve health care outcomes in immigrants.

Keywords: health care strategy; hypertension; immigrants; usual source of care.

Grants and funding

This research was funded by the Basic Science Research Program through the National Research Foundation of Korea (NRF) (2017R1D1A1B03034121). However, the funding body had no influence on conducting the research or writing the manuscript.