Abstract
BACKGROUND: Health concordance within couples presents a promising opportunity to design interventions for disease management, including hypertension. We compared the concordance of prevalent hypertension within middle-aged and older heterosexual couples in the United States, England, China, and India. METHODS AND RESULTS: Cross-sectional dyadic data on heterosexual couples were used from contemporaneous waves of the HRS (US Health and Retirement Study, 2016/17, n=3989 couples), ELSA (English Longitudinal Study on Aging, 2016/17, n=1086), CHARLS (China Health and Retirement Longitudinal Study, 2015/16, n=6514), and LASI (Longitudinal Aging Study in India, 2017/19, n=22389). Concordant hypertension was defined as both husband and wife in a couple having hypertension. The prevalence of concordant hypertension within couples was 37.9% (95% CI, 35.8–40.0) in the United States, 47.1% (95% CI, 43.2-50.9) in England, 20.8% (95% CI, 19.6–21.9) in China, and 19.8% (95% CI, 19.0–20.5) in India. Compared with wives married to husbands without hypertension, wives married to husbands with hypertension were more likely to have hypertension in the United States (prevalence ratio, 1.09 [95% CI, 1.01- 1.17), England (prevalence ratio, 1.09, 95% CI, 0.98–1.21), China (prevalence ratio, 1.26 [95% CI, 1.17-1.35), and India (prevalence ratio, 1.19 [95% CI, 1.15-1.24]). Within each country, similar associations were observed for husbands. Across countries, associations in the United States and England were similar, whereas they were slightly larger in China and India. CONCLUSIONS: Concordance of hypertension within heterosexual couples was consistently observed across these 4 socially and economically diverse countries. Couple-centered interventions may be an efficient strategy to prevent and manage hypertension in these countries.
Generated Summary
This cross-sectional study investigated spousal concordance of hypertension among heterosexual couples in the United States, England, China, and India, using population-representative data. The study aimed to compare the prevalence of concordant hypertension and its associations within and between these countries, focusing on sex differences and the potential for couple-centered interventions. The research utilized data from the HRS (US Health and Retirement Study), ELSA (English Longitudinal Study on Aging), CHARLS (China Health and Retirement Longitudinal Study), and LASI (Longitudinal Aging Study in India), employing cross-sectional dyadic data. The methodology involved defining concordant hypertension, assessing prevalence, and analyzing associations between couples’ hypertension status. Statistical analyses included Poisson regression with logarithmic link function and robust standard errors to estimate prevalence ratios, along with adjustments for individual, spousal, and household characteristics. The study examined sex differences in associations and country-level variations, using generalized estimating equations and incorporating complex survey designs.
Key Findings & Statistics
- The prevalence of concordant hypertension within couples was 37.9% (95% CI, 35.8–40.0) in the United States, 47.1% (95% CI, 43.2-50.9) in England, 20.8% (95% CI, 19.6–21.9) in China, and 19.8% (95% CI, 19.0–20.5) in India.
- The prevalence of hypertension among wives was lower than among husbands across countries.
- Compared with wives married to husbands without hypertension, wives married to husbands with hypertension were more likely to have hypertension in the United States (prevalence ratio, 1.09 [95% CI, 1.01- 1.17]), England (prevalence ratio, 1.09, 95% CI, 0.98–1.21), China (prevalence ratio, 1.26 [95% CI, 1.17-1.35]), and India (prevalence ratio, 1.19 [95% CI, 1.15-1.24]).
- Compared with husbands who had wives without hypertension, husbands who had wives with hypertension were more likely to have hypertension in the United States (PR, 1.06 [95% CI, 1.00-1.13]), England (PR, 1.05 [95% CI, 0.96–1.16]), China (PR, 1.26 [95% CI, 1.18-1.35]), and India (PR, 1.20 [95% CI, 1.12–1.28]).
- No sex differences were observed in the magnitude of associations for hypertension when comparing husbands and wives.
- Comparing husbands to wives, the difference in association (in multiplicative scale; exponent of interaction term) was 0.92 (95% CI, 0.83-1.02) in the United States, 0.95 (95% CI, 0.82–1.10) in England, 0.94 (95% CI, 0.85–1.04) in China, and 0.97 (95% CI, 0.92–1.03) in India.
- Across countries, the difference in association, compared with the United States, was 0.97 (95% CI, 0.88–1.11) in England, 1.13 (95% CI, 1.01–1.26) in China, and 1.19 (95% CI, 1.08–1.31) in India; among husbands, the difference in association was 0.98 (95% CI, 0.88–1.11) in England, 1.18 (95% CI, 1.07–1.29) in China, and 1.20 (95% CI, 1.11–1.30) in India.
Other Important Findings
- Major variations in household and individual characteristics were observed across countries, with the mean age ranging from 51.1 (India) to 72.5 (England) among wives and 57.2 (India) to 74.2 (England) among husbands.
- Distributions of systolic and diastolic blood pressure varied among wives and husbands by country.
- Associations of hypertension status within couples remained consistent when analyses were stratified by residence, household wealth quintile, marriage length, age groups, and education levels.
Limitations Noted in the Document
- The study’s cross-sectional design limits the ability to assess changes in spousal concordance over time.
- Hypertension was defined based on a single time point of blood pressure measurement, which may not fully capture the prevalence as clinical guidelines recommend multiple measurements.
- The study acknowledges the potential for statistical artifacts due to similar marginal prevalence of hypertension among spouses and between countries.
- The study primarily focused on primary hypertension related to lifestyle and excluded those with hypertension secondary to other disease processes.
Conclusion
The study’s findings highlight a significant prevalence of concordant hypertension among couples across the United States, England, China, and India. The consistent associations observed within each country, along with the high prevalence of hypertension overall, suggests that couple-based interventions could be a valuable approach to hypertension management. The observation that spousal concordance was slightly stronger in China and India, compared to the United States and England, suggests that cultural contexts may play a role in the dynamics of health within couples. The study implies that implementing couple-based screening, offering joint treatment plans, and encouraging couples to manage their health together could lead to better outcomes. As the study notes, the potential number of people with spousal concordance in hypertension would likely be very large given the increasing prevalence of hypertension. This reinforces the potential for population-level improvements through couple-centered interventions. In discussing the observed associations, the study highlights that the mechanisms of assortative mating or cohabitation may be at play, influencing the likelihood of couples sharing similar health profiles. The authors emphasize that interventions targeting couples could improve hypertension diagnosis and management. The study recognizes the potential for couple-based strategies to achieve better diagnostic and treatment outcomes, especially in settings where hypertension is an emerging public health issue. Furthermore, the results of the study suggest that screening married couples and designing couple-based interventions around the family unit may improve hypertension diagnosis and management. The consistent associations observed across various socioeconomic subgroups strengthen the findings, pointing to the broad applicability of couple-focused approaches.