Cost-effectiveness of treatment in adults with blood pressure of 130-139/80-89 mmHg and high cardiovascular risk in China: a modelling study

Association of high-normal blood pressure defined by the 2023 European Society of Hypertension guideline with mortality in the Chinese population: a nationwide, population-based, prospective study of 3.6 million adults

BACKGROUND

The relationship between high-normal blood pressure (BP) and mortality lacks high-quality evidence based on large population cohorts. This study aims to comprehensively investigate the association of high-normal BP and its trajectory with all-cause and cause-specific mortality.

METHODS

In this community-based population cohort from the China Health Evaluation And risk Reduction Through nationwide teamwork (ChinaHEART) project, 3,598,940 participants aged 35-75 years with data for baseline BP were included. High-normal BP was defined as a systolic BP (SBP) of 130-139 mmHg and/or a diastolic BP (DBP) of 85-89 mmHg at baseline. Overall, 78,130 participants with three or more BP measurements were included in the trajectory pattern analysis during the follow-up. Four BP change trajectory patterns were identified.

RESULTS

For the baseline BP analysis, compared with the optimal BP group (SBP < 120 mmHg and DBP < 80 mmHg [18.1%]), participants with high-normal BP (18.7%) had an increase of 4% in all-cause mortality risk (hazard ratio [HR] 1.04, 95% confidence interval [CI] 1.01-1.07) and an increase of 28% in cardiovascular disease (CVD) mortality risk (HR 1.28, 95% CI 1.21-1.34), with the greatest increase in mortality risk observed for hemorrhagic stroke (HR 1.75, 95% CI 1.55-1.98). Among the BP trajectory patterns, compared with participants with optimal-stable BP, those with high-normal-increasing BP had an increase of 35% in all-cause mortality risk (HR 1.35, 95% CI 1.07-1.70) and an increase in CVD mortality risk of 57% (HR 1.57, 95% CI 1.11-2.24), with the greatest increase in mortality risk also observed for hemorrhagic stroke (HR 3.75, 95% CI 1.50-9.34). Approximately 0.7% and 1.6% of all-cause mortality was attributable to high-normal BP at baseline and the high-normal-increasing BP trajectory pattern, respectively.

CONCLUSIONS

Individuals with high-normal BP at baseline exhibited a significantly elevated mortality risk and especially for risk of hemorrhagic stroke mortality during the follow-up. This positive association may be mainly attributed to the "high-normal-increasing" BP change over time.

Cost-Effectiveness of Salt Substitution and Antihypertensive Drug Treatment in Chinese Prehypertensive Adults

BACKGROUND

Recent guidelines recommend antihypertensive drug treatment for prehypertensive individuals with blood pressure between 130/80 and 139/89 mm Hg. This study evaluates the cost-effectiveness of 3 interventions in Chinese prehypertensive adults: salt substitution, antihypertensive drug treatment, and their combination.

METHODS

We developed a Markov cohort model to estimate cardiovascular disease (CVD) events, costs, and quality-adjusted life years (QALYs) over a lifetime. Data from the China Kadoorie Biobank informed the simulation. Costs and utilities were drawn from published sources. We evaluated the cost-effectiveness of salt substitution alone, antihypertensive drug treatment alone, and a combination of the 2, focusing on the overall prehypertensive population, those at high CVD risk, and different starting ages (40, 50, 60, and 70 years). Incremental cost-effectiveness ratios (ICERs) were calculated per QALY gained.

RESULTS

Salt substitution at age 40 years is the only cost-effective strategy for prehypertensive individuals, with an ICER of $6413.62/QALY. For those at high CVD risk, the combination intervention starting at age 40 years is most cost-effective, with an ICER of $2913.30/QALY. Interventions initiated at younger ages yielded greater CVD reductions and lower ICERs. For example, a combined intervention at age 40 years reduces CVD events by 5.3% with an ICER of $2913.30/QALY, compared with 4.9% and $32 635.33/QALY at age 70 years. These results were consistent across sensitivity analyses.

CONCLUSIONS

In China, replacing usual salt with a salt substitute is more cost-effective than treating prehypertensive individuals over the age of 40 years with antihypertensive drugs. Furthermore, starting intervention at a younger age in prehypertensive adults can result in even greater cost savings.

[Comparison of initiation of antihypertensive therapy strategies for primary prevention of cardiovascular diseases in Chinese population: A decision-analytic Markov modelling study]

OBJECTIVE

To evaluate the health benefits and intervention efficiency of different strategies of initiating antihypertensive therapy for the primary prevention of cardiovascular diseases in a community-based Chinese population from the Chinese electronic health records research in Yinzhou (CHERRY) study.

METHODS

A decision-analytic Markov model was used to simulate and compare different antihypertensive initiation strategies, including: Strategy 1, initiation of antihypertensive therapy for Chinese adults with systolic blood pressure (SBP) ≥140 mmHg (2020 Chinese guideline on the primary prevention of cardiovascular diseases); Strategy 2, initiation of antihypertensive therapy for Chinese adults with SBP ≥130 mmHg; Strategy 3, initiation of antihypertensive therapy for Chinese adults with SBP≥140 mmHg, or with SBP between 130 and 140 mmHg and at high risk of cardiovascular diseases (2017 American College of Cardiology/American Heart Association guideline for the prevention, detection, evaluation, and management of high blood pressure in adults); Strategy 4, initiation of antihypertensive therapy for Chinese adults with SBP≥160 mmHg, or with SBP between 140 and 160 mmHg and at high risk of cardiovascular diseases (2019 United Kingdom National Institute for Health and Care Excellence guideline for the hypertension in adults: Diagnosis and management). The high 10-year cardiovascular risk was defined as the predicted risk over 10% based on the 2019 World Health Organization cardiovascular disease risk charts. Different strategies were simulated by the Markov model for ten years (cycles), with parameters mainly from the CHERRY study or published literature. After ten cycles of simulation, the numbers of quality-adjusted life years (QALY), cardiovascular events and all-cause deaths were calculated to evaluate the health benefits of each strategy, and the numbers needed to treat (NNT) for each cardiovascular event or all-cause death could be prevented were calculated to assess the intervention efficiency. One-way sensitivity analysis on the uncertainty of incidence rates of cardiovascular disease and probabilistic sensitivity analysis on the uncertainty of hazard ratios of interventions were conducted.

RESULTS

A total of 213 987 Chinese adults aged 35-79 years without cardiovascular diseases were included. Compared with strategy 1, the number of cardiovascular events that could be prevented in strategy 2 increased by 666 (95% UI: 334-975), while the NNT per cardiovascular event prevented increased by 10 (95% UI: 7-20). In contrast to strategy 1, the number of cardiovascular events that could be prevented in strategy 3 increased by 388 (95% UI: 194-569), and the NNT per cardiovascular event prevented decreased by 6 (95% UI: 4-12), suggesting that strategy 3 had better health benefits and intervention efficiency. Compared to strategy 1, although the number of cardiovascular events that could be prevented decreased by 193 (95% UI: 98-281) in strategy 4, the NNT per cardiovascular event prevented decreased by 18 (95% UI: 13-37) with better efficiency. The results were consistent in the sensitivity analyses.

CONCLUSION

When initiating antihypertensive therapy in an economically developed area of China, the strategy combined with cardiovascular risk assessment is more efficient than those purely based on the SBP threshold. The cardiovascular risk assessment strategy with different SBP thresholds is suggested to balance health benefits and intervention efficiency in diverse populations.

Cost-Effectiveness of a Multicomponent Primary Care Intervention for Hypertension

BACKGROUND

The SingHypertension primary care clinic intervention, which consisted of clinician training in hypertension management, subsidized single-pill combination medications, nurse-delivered motivational conversations and telephone follow-ups, improved blood pressure control and cardiovascular disease (CVD) risk scores relative to usual care among patients with uncontrolled hypertension in Singapore. This study quantified the incremental cost-effectiveness, in terms of incremental cost per unit reduction disability-adjusted life years, of SingHypertension relative to usual care for patients with hypertension from the health system perspective.

METHODS AND RESULTS

We developed a Markov model to simulate CVD events and associated outcomes for a hypothetical cohort of patients over a 10-year period. Costs were measured in US dollars, and effectiveness was measured in disability-adjusted life years averted. We present base-case results and conducted deterministic and probabilistic sensitivity analyses. Based on a willingness-to-pay threshold of US $55 500 per DALY averted, SingHypertension was cost-effective for patients with hypertension (incremental cost-effectiveness ratio: US $24 765 per disability-adjusted life year averted) relative to usual care. This result held even if risk reduction was assumed to decline linearly to 0 over 10 years but not sooner than 7 years. Incremental cost-effectiveness ratios were most sensitive to the magnitude of the reduction in CVD risk; at least a 0.13% to 0.16% point reduction in 10-year CVD risk is required for cost-effectiveness. Probabilistic sensitivity analysis indicates that SingHypertension has a 78% chance of being cost-effective at the willingness-to-pay threshold.

CONCLUSIONS

SingHypertension represents good value for the money for reducing CVD incidence, morbidity, and mortality and should be considered for wide-scale implementation in Singapore and possibly other countries.

REGISTRATION INFORMATION

REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02972619.