Background Place-based characteristics have been implicated as determinants of socioeconomic inequalities in cardiovascular-related health risk factors (such as hypertension) and in use of healthcare services. In Chile, one-third of adults are hypertensive. Chilean evidence has documented inequalities in hypertension by various measures of individual socioeconomic position (SEP). However, more research is needed to assess the contribution of area-level contextual factors such as income inequality on hypertension management inequalities.

Methods Data came from the Chilean Health Surveys (2003, 2010, 2017: N=13,605 participants aged 17 years and older). Our outcomes were hypertension and management indicators (e.g. treatment among hypertensives). Hypertension was defined as SBP/DBP of at least 140/90 mmHg or use of antihypertensive medication. Years of formal education was our chosen measure of individual SEP; at the county-level, the Gini coefficient was used as an index of income inequality. Our models, adjusted for the complex survey design, were age (categorized as 17–64 or 65+ years) -and gender-specific. We compared two models. First, a fixed model assessed inequalities using individual-level SEP. Secondly, multilevel analyses assessed inequalities using individual-level SEP after adjustment for the Gini coefficient. Inequalities were summarised using the Slope and Relative Indices of Inequality (SII and RII, respectively). For brevity, we report only the RII (values above 1 indicate higher outcomes amongst those with lower education).

Results Hypertension prevalence was 34.0% (95% CI: 31.6–36.4), 32.0% (29.9–34.2) and 30.8% (28.7–32.9) in 2003, 2010 and 2017, respectively. Levels of treatment among hypertensives was 38.5% (34.9–42.3), 56.5% (52.3–60.6) and 65.2% (61.2–68.9) in 2003, 2010 and 2017, respectively. Inequalities in hypertension were higher in 2017 after adjustment for the Gini coefficient. For example, in the fixed-effects model, the RII for hypertension among persons aged below 65 years was 2.9 (95% CI: 1.6–5.2) and 5.8 (2.5–9.7) for males and females, respectively. After adjustment for the Gini coefficient, the RII increased to 4.2 (2.6–6.6) and 6.3 (3.9–10.1) for males and females, respectively. Inequalities in treatment among older hypertensive females were similar in magnitude before and after adjustment for the Gini coefficient, with an estimated RII of 0.6 (0.5–0.8) and 0.7 (0.5–0.8) respectively.

Conclusion Multilevel analyses are required to better estimate inequalities. Chile currently needs interventions to improve the management of hypertension and simultaneously, decrease inequalities, first, in hypertension prevalence among younger males and females and, secondly, in its management among older hypertensive females.

The Chilean National Health Surveys 2003–2010–2017 were funded by the Chilean Ministry of Health.

This study is part of Alvaro Passi-Solar’s PhD research, funded by the Chilean Ministry of Education (ANID-Conicyt).