Evidence for the association between the frailty index and cardiovascular disease (CVD) is inconclusive, and this association has not been evaluated in Chinese adults. We aim to examine the association between the frailty index and CVD among middle-aged and older Chinese adults. We conducted cross-sectional and cohort analyses using nationally representative data from the China Health and Retirement Longitudinal Study (CHARLS). From 2011 to 2018, 17,708 participants aged 45 years and older were included in the CHARLS. The primary outcome was CVD events (composite of heart disease and stroke). Multivariable adjusted logistic regression and Cox proportional hazards models were used to estimate the association between the frailty index and CVD in cross-sectional and follow-up studies, respectively. A restricted cubic spline model was used to characterize dose–response relationships. A total of 16,293 and 13,580 participants aged 45 years and older were included in the cross-sectional and cohort analyses, respectively. In the cross-sectional study, the prevalence of CVD in robust, pre-frailty and frailty was 7.83%, 18.70% and 32.39%, respectively. After multivariable adjustment, pre-frailty and frailty were associated with CVD; ORs were 2.54 (95% confidence interval [CI], 2.28–2.84) and 4.76 (95% CI, 4.10–5.52), respectively. During the 7 years of follow-up, 2122 participants without previous CVD developed incident CVD; pre-frailty and frailty were associated with increased risk of CVD events; HRs were 1.53 (95% CI, 1.39–1.68) and 2.17 (95% CI, 1.88–2.50), respectively. Furthermore, a stronger association of the frailty index with CVD was observed in participants aged <55, men, rural community-dwellers, BMI ≥ 25, without hypertension, diabetes or dyslipidemia. A clear nonlinear dose–response pattern between the frailty index and CVD was widely observed (p < 0.001 for nonlinearity), the frailty index was above 0.08, and the hazard ratio per standard deviation was 1.18 (95% CI 1.13–1.25). We observed the association between the frailty index and CVD among middle-aged and elderly adults in China, independent of chronological age and other CVD risk factors. Our findings are important for prevention strategies aimed at reducing the growing burden of CVD in older adults.

Background: The most effective way to prevent hepatitis B virus (HBV) infection is vaccination. Synthesized data on vaccination coverage in adults against hepatitis B in China are scarce. We aimed to estimate the hepatitis B vaccination rate in adults in China. Methods: We searched PubMed, EMBASE, Cochrane Library, China National Knowledge Infrastructure, WanFang, and Sinomed databases for observational studies published between 1 January 2011 and 1 October 2021. Data were extracted using a standardized form to estimate the pooled vaccination coverage rate and 95% confidence intervals (CI) based on inclusion and exclusion criteria. Subgroup analysis was employed to explore heterogeneity. This study is registered in PROSPERO, CRD42021293175. Results: We identified 5128 records, of which 21 articles that included 34,6571 adults. The pooled coverage rate and 95% confidence intervals were 26.27% and 22.73–29.82%, respectively. The pooled coverage rates were 22.06% (95% CI: 15.35–28.78%), 33.81% (95% CI: 28.77–38.85%) and 23.50% (95% CI: 17.37–29.64%) in eastern China, central China and western China, respectively. Furthermore, males had a pooled hepatitis B vaccination coverage rate of 23.47% (95% CI: 15.61–31.33%), whereas, in females, the coverage rate was 26.60% (95% CI: 18.73–34.47%). The pooled hepatitis B vaccination coverage rate in the age group younger than 40 years was 36.93% (95% CI: 28.35–45.50%), while in the ≥40-year-old group, the pooled hepatitis B vaccination coverage rate was 17.09% (95% CI: 10.18–24.00%). The pooled hepatitis B vaccination coverage rate in urban areas (40.29%, 95% CI: 20.91–59.67%) was higher than in rural areas (16.54%, 95% CI: 7.80–25.29%). The average weighted, pooled hepatitis B vaccination coverage rate was 26.53% (20.25–32.81%) in 2011–2015 and 26.12% (22.04–30.20%) in 2016–2021. Conclusions: This systematic review provides the hepatitis B vaccination coverage rate of adults in China (26.27%). The low prevalence of vaccine-mediated immunity among adults in China underscores the urgent need for targeted immunization strategies for vulnerable Chinese adults to ensure progress toward the target of eliminating hepatitis B by 2030.

Hepatitis B vaccination coverage rates are low throughout most populations in China. Factors influencing low coverage rates, including population-specific hepatitis B vaccination barriers, may inform policies that promote vaccination. A cross-sectional survey of residents from 43 communities assessed their vaccination status and identified associated factors via uni- and multivariable logistic regression and subgroup analyses. In total, 11,280 of 36,007 respondents received a hepatitis B vaccine, indicating a 31.33% coverage rate. Multivariable logistic regression revealed non-Beijing (odds ratio (OR) = 0.81; 95% confidence interval (CI): 0.76–0.85) and residents who self-rated their health as very healthy (OR = 0.82; 95% CI: 0.68–0.99) were unlikely to be vaccinated. Farmers (OR = 1.68; 95% CI: 1.51–1.86), commerce and service workers (OR = 1.82; 95% CI, 1.63–2.04), government employees (OR = 1.56; 95% CI: 1.38–1.77), professionals and technicians (OR = 1.85; 95% CI: 1.63–2.09), and students (OR = 1.69; 95% CI: 1.10–2.59) had increased hepatitis B vaccination rates. The multivariable assessment revealed hepatitis B vaccination coverage rates are associated with confirmed or suspected family cases, vaccination unwillingness or uncertainty, and unawareness of its prevention of the hepatitis B virus. Low hepatitis B vaccination coverage rates among Beijing subpopulations highlight the need for improved strategies, including those that target specific populations.

Evidence on the effectiveness of hepatitis B virus (HBV) infection screening and vaccination programs remains rare in China. We used a quasi-experimental method, propensity score matching, to evaluate the effects of a community-based HBV infection detection combined with vaccination (HBVIDV) program in a pilot. Data were retrieved from the HBVIDV program implemented between July 2019 and June 2020. Outcomes were the difference between the treatment and control groups in hepatitis B vaccination (≥1 dose), hepatitis B vaccine series completion (≥3 doses), and serologic evidence of vaccine-mediated immunity. Altogether, 26,180 individuals were included, where 6160 (23.5%) individuals were assigned to the treatment group, and 20,020 (76.5%) individuals were assigned to the control group. After propensity score matching, 5793 individuals were matched. The rates of hepatitis B vaccination, hepatitis B vaccine series completion, and prevalence of vaccine-mediated immunity in the treatment and control groups were 29.0% vs. 17.8%, 22.1% vs. 13.1%, and 38.2% vs. 27.6%, respectively. The HBVIDV program was significantly associated with increased hepatitis B vaccination rate (OR, 1.884, 95% CI 1.725–2.057), hepatitis B vaccine series completion rate (OR, 1.872, 95% CI 1.696–2.065), and prevalence of vaccine-mediated immunity (OR, 1.623, 95% CI 1.501–1.755). The greater magnitude of association between HBVIDV program and outcomes was observed among adults aged 35–54 years and adults who live in rural areas. The HBVIDV program was effective in increasing the hepatitis B vaccination rate, hepatitis B vaccine series completion rate, and prevalence of vaccine-mediated immunity among adults in the pilot. Further focusing the program on special populations and regions may produce more effective results.