Targeting hypertension screening in low- and middle-income countries: A cross-sectional analysis of 1.2 million adults in 56 countries

Background: As screening programs in low- and middle-income countries (LMICs) usually do not have the resources to screen the entire population, there is a need to target such efforts to easily identifiable priority groups. This study aimed to determine i) how hypertension prevalence in LMICs varies by age, sex, body mass index (BMI), and smoking status, and ii) the ability of different combinations of these variables to accurately predict hypertension.
Methods and Results: We analyzed individual-level, nationally representative data from 1,170,629 participants in 56 LMICs, of whom 220,636 (18.8%) had hypertension. Hypertension was defined as systolic blood pressure (BP) ≥140 mmHg, diastolic BP ≥90 mmHg, or reporting to be taking BP-lowering medication. The shape of the positive association of hypertension with age and BMI varied across world regions. We used logistic regression and random forest models to compute the area under the Receiver Operating Characteristic curve (AUC) in each country for different combinations of age, BMI, sex, and smoking status. The AUC for the model with all four predictors ranged from 0.64 to 0.85 between countries with a country-level mean of 0.76 across LMICs globally. The mean absolute increase in the AUC from the model including only age to the model including all four predictors was 0.05.
Conclusion: Adding BMI, sex and smoking status to age led only to a minor increase in the ability to distinguish between adults with and without hypertension compared to using age alone. Hypertension screening programs in LMICs could use age as a primary variable to target their efforts.