# Long-Term Effects of Sustained Regular Medication in Hypertensive Patients in Yunnan, China: A Cohort Study of 5 Years' Follow-Up

## TL;DR

This study shows that consistent medication use in hypertensive patients in Yunnan, China, improves blood pressure control and reduces cardiovascular risks over five years.

## Contribution

The study demonstrates the long-term impact of medication compliance on blood pressure control and cardiovascular outcomes in a real-world public health program setting.

## Key findings

- Sustained medication compliance led to the largest decline in systolic blood pressure over five years.
- The sustained group achieved a 70% blood pressure control rate by 2022, significantly higher than other groups.
- Poor compliance was linked to a 1.115 times higher referral rate and increased cardiovascular disease risk.

## Abstract

Background: The relationship between different grades of compliance to antihypertensive medication and blood pressure (BP) control rate remains unclear. This study highlighted the Chinese Basic Public Health Service (BPHS) program upgraded antihypertension medication compliance to improve the blood pressure control rate contributing to the UN sustainable development goal of lowering chronic illness fatalities by one-third by 2030.

Methods: In 2015, 1254 hypertensive patients aged ≥ 35 years were selected in the baseline survey in Yunnan Province by a multistage stratified random sampling method and followed up from 2018 to 2022. Then, they were divided into three groups by tertiles as antihypertensive medicine compliance “poor,” “intermittent,” and “sustained” groups. Then, the robust variance Poisson regression models were performed to estimate the association between three groups and the number of referrals. Kaplan–Meier curves calculated the cumulative risk of onset and survival probability of cardiovascular events from three medication compliance groups.

Results: A total of 1254 hypertension patients were included in the study; 992, 1218, 1121, 1066, and 999 hypertension patients were followed up annually. From the baseline to last follow-up, systolic BP declined with the largest decrease in the sustained group (2015: 152.88 ± 21.64 mmHg vs. 2022: 134.61 ± 10.49 mmHg, p < 0.05) and the least decrease in the poor group (2015: 157.07 ± 15.37 mmHg vs. 2022: 140.33 ± 12.04 mmHg, p < 0.05). Under the management of BPHS, the BP control rate of all three groups increased significantly. Compared with the baseline, the control rate in the sustained group reached 70% in 2022 (p < 0.01). The number of referrals from the poor group was 11.5%, higher compared with the sustained group (IRR = 1.115 and 95% CI: 1.043–1.193). The poor group also had the highest probability of cardiovascular disease (CVD). The survival probability in the sustained group was the highest and kept at 0.950 at the end of 5 years.

Conclusions: High-grade compliance to antihypertensive drugs significantly improves BP control rate and reduces the risk of CVD events and mortality. The decline of medication compliance grades is closely related to decreasing BP control rate and increased risk of CVD and mortality.