Study design and model population

We performed a model-based economic evaluation to assess the incremental cost-effectiveness ratio (ICER), with the outcomes expressed as cost per quality-adjusted life year (QALY) of drug treatment compared with non-drug treatment from a societal perspective for stage 1 hypertensive patients aged <60 years with high CVD risk. The ICER less than one time of per capita gross domestic product (GDP) per QALYs gained was considered as highly cost-effective [10]. According to the China Health Statistics Yearbook report, the per capita GDP was $10438.66 in 2020 (US$1.00 = 6.8974 Renminbi (RMB)) [11]. The model development and analyses were performed using TreeAge Pro Suite 2022 (TreeAge Software, Inc, Williamstown, Mass). This study conformed to the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) guidelines and checklist items [12].

We modeled the cost-effectiveness of drug treatment for stage 1 hypertensive patients in the Kailuan study, a prospective dynamic cohort study in Tangshan, China. The detailed study design of the hypertension management programme has been described previously [13]. Briefly, the Kailuan study was initiated in 2006 and enrolled 101 517 employees in the 2006-2007 cycle and 25 337, 10 519, 21 651, 12 396, 7907 and 6921 new employees were additionally enrolled in 2008-2009, 2010-2011, 2012-2013, 2014-2015, 2016-2017 and 2018-2020 cycles, respectively. In the present study, we further excluded those with missing information of baseline BP (n = 2054), those with self-reported pre-existing CVD or diabetes at baseline (n = 16 304), those aged ≥60 years (n = 32 890), and those with less than three CVD risk factors (n = 91 344, defined as >55 years for men or >65 years for women, current smoking, low-density lipoprotein cholesterol ≥3.4 millimoles per litre (mmol/l) (130 milligrammes per decilitre (mg/dl)), high-density lipoprotein cholesterol <1.04 mmol/l (40 mg/dl), fasting blood glucose >6.0 mmol/l or body mass index (BMI)≥28.0 kilogrammes per square metre (kg/m²), according to the 2018 Chinese guidelines) [4], those with optimal BP or elevated BP levels (n = 9563, defined as SBP<130 mm Hg and DBP<80 mm Hg), leaving 34 093 participants in the study population. A flowchart of sample selection is shown in Figure S1 in the Online Supplementary Document, and baseline characteristics of study participants are shown in Table S1 in the Online Supplementary Document.