Hypertension care cascade in Chile: a serial cross-sectional study of national health surveys 2003-2010-2017

BACKGROUND: Trend data on hypertension prevalence and attainment indicators at each step of the care cascade (awareness, treatment, control) are required in Chile. This study aims to quantify trends (2003–2017) in prevalence and in the proportion of individuals with hypertension attaining each step of the care cascade among adults aged 17 years or older, and to assess the impact of lowering the blood pressure (BP) thresholds used to define elevated BP on these indicators. METHODS: We used data from 2003, 2010, and 2017 Chilean national health surveys. Each year we assessed levels of (1) mean systolic (SBP) and diastolic (DBP) blood pressure, (2) hypertension prevalence (BP ≥ 140/90 mmHg or use of antihypertensive treatment), and (3) awareness, treatment, and control. Logistic regression on pooled data was used to assess trends in binary outcomes; linear regression was used to assess trends in continuous SBP and DBP. We compared levels of hypertension prevalence using two sources to ascertain antihypertensive treatment (self-reported versus medicine inventory). The 2017 American College of Cardiology/American Heart Association (ACC/AHA) guidelines were used to re-define hypertension using lower thresholds (BP ≥ 130/80 mmHg). RESULTS: Hypertension prevalence was 34.0, 32.0 and 30.8% in 2003, 2010 and 2017, respectively. Levels of treated- and controlled-hypertension were significantly higher in 2017 than in 2003 (65% versus 41% for treatment, P < 0.001; 34% versus 14% for control, P < 0.001), while levels of awareness were stable (66% versus 59%, P = 0.130). Awareness, treatment, and control levels were higher among females in 2003, 2010, and 2017 (P < 0.001). Mean SBP and DBP decreased over the 15-year period, except for SBP among females on treatment. Adopting the 2017 ACC/AHA guidelines would increase hypertension prevalence by 17 and 55% in absolute and relative terms, respectively. CONCLUSIONS: Chile has experienced a positive population-wide lowering in blood pressure distribution which may be explained partly by a significant rise in levels of treated- and controlled-hypertension since 2003. Lowering the thresholds used to define elevated BP would substantially increase the financial public health challenge of further improving attainment levels at each step of the care cascade. Innovative and collaborative strategies are needed to improve hypertension management, especially among males.