Pharmacological therapy and blood pressure control in primary health care sites in China: data from 254,848 hypertensive patients

Background: Studies on pharmacological therapy and blood pressure (BP) control in primary health care sites of China are limited. We aimed to investigate drug use and compliance as well as compare BP control between pharmacological therapies for lowering BP in hypertensive population serviced by these sites. Methods: This is a 1-year cohort study using electronic health care records from the National Primary Public Health Services of China. For patients with antihypertensive drugs at the first follow-up, we defined compliance with treatment as a continued treatment with the same specified class of agents at next three follow-ups. In those with compliance, BP control was defined as systolic BP <140 mmHg and diastolic BP <90 mmHg in four follow-ups within 1 year. Results: Primary health care sites of four areas managed 254,848 hypertensive patients aged ≥35 years. At the first follow-up, 50.2% of the patients took medicines for lowering BP. In those, calcium channel antagonist monotherapy was the most common medicine in urban areas (57.1% vs 15.6% in rural areas, P <0.001); however, the most common one was single-pill combinations including diuretics and non-first-line drugs in rural areas (34.4% vs 10.7% in urban areas, P <0.001). Compliance was 79.9% and 53.2% for single- and multiple-pill combinations in first-line drugs; this rate was 69.5% and 45.0% in regimens combined with non-first-line drugs, respectively. Compared with calcium channel antagonists, diuretics monotherapy increased the overall BP control by 11% (risk ratio, 1.11; 95% confidence interval, 1.08 to 1.13), but it was used in few patients (3.3%); first-line multiple-pill combinations significantly decreased BP control by 20% to 28% in three less urbanized areas, but a similar BP control was achieved in the highly urbanized area. Conclusion: Our study indicated that drug use such as diuretics could be strengthened in primary health care sites and combined therapy may be improved particularly in less urbanized areas.