Pathways linking relative deprivation to blood pressure control: the mediating role of depression and medication adherence among Chinese middle-aged and older hypertensive patients

BACKGROUND: Studies have demonstrated that individuals of low socioeconomic status have higher blood pressure. Yet, whether socioeconomic inequality would influence blood pressure control and the underlying mechanisms associated with socioeconomic inequality in blood pressure control are unknown. Central to socioeconomic inequality is relative deprivation. We aim to examine the association between relative deprivation and blood pressure control and to investigate the pathways of the association among middle-aged and older adults with hypertension. METHODS: Data were collected from the 2020 Household Health Interview Survey in Taian City, Shandong province. This study included 2382 eligible respondents aged 45 years and older with a diagnosis of hypertension. Our primary outcome was dichotomous blood pressure control. Relative deprivation was calculated with the Deaton Index. Depressive symptoms and medication adherence were considered as mediators. Multivariable binary logistic regression models were used to estimate the effect of relative deprivation on blood pressure control. The “KHB-method” was used to perform mediation analysis. RESULTS: Among 2382 middle-aged and older adults with hypertension, the mean age was 64.9 years (SD 9.1), with 61.3% females. The overall proportion of participants with uncontrolled blood pressure was 65.1%. Increased relative deprivation was likely to have higher odds of uncontrolled blood pressure (OR: 2.35, 95%CI: 1.78–7.14). Furthermore, depressive symptoms and medication adherence partially mediated the overall association between relative deprivation and blood pressure control, with depressive symptoms and medication adherence explaining 5.91% and 37.76%, respectively, of the total effect of relative deprivation on blood pressure control. CONCLUSIONS: Individual relative deprivation could threaten blood pressure control among middle-aged and older hypertension patients through the mechanisms of depression and medication adherence. Hence, improving blood pressure control may require more than just health management and education but fundamental reform of the income distribution and social security system to narrow the income gap, reducing relative economic deprivation. Additionally, interventions tailoring psychological services and medication adherence could be designed to reduce the harmful effect of relative deprivation on blood pressure control among disadvantaged individuals.