Individual-level and community-level factors for 10-year cardiovascular disease risk in Ethiopia: a retrospective, population-based, cross-sectional, observational study.

Background: No study has quantified the 10-year cardiovascular disease (CVD) risk in individuals without previous CVD in Ethiopia using the latest 2019 WHO CVD risk equation. Our study aimed to quantify the proportion of the Ethiopian population with at least a 10% risk of developing primary CVD in the following 10 years, and to identify variations in risk associated with individual-level and community-level factors.

Methods: This retrospective, population-based, cross-sectional, observational study used data on Ethiopians aged 40-69 years from across enumeration areas sampled in the WHO STEPwise Approach to Noncommunicable Disease Risk Factor Surveillance (STEPS) national survey. The survey was conducted between April 14 and June 26, 2015. The outcome variable was 10-year CVD risk, calculated using the 2019 WHO CVD risk equation. Risk factors used to calculate 10-year CVD risk were age, smoking status, systolic blood pressure, history of diabetes, and total cholesterol. Participants with missing data on risk factors were excluded, as were pregnant individuals and those with a history of CVD. Multilevel regression analyses were used to identify individual-level and community-level factors associated with 10-year primary CVD risk.

Findings: Of 2658 Ethiopian participants from 453 enumeration areas included in the analysis (1207 [45·4%] male and 1451 [54·6%] female), 7·3% (95% CI 6·3-8·2) had a 10-year CVD risk of at least 10%. Overall, 10-year CVD risk was higher in urban residents (β coefficient percentage 0·88%, 95% CI 0·60-1·15; p<0·0001) versus rural residents, in participants who were retired or unable to work (0·50, 0·05-0·96; p=0·028) versus working or unemployed participants, and in participants with low physical activity (0·46, 0·16-0·76; p=0·0021) versus participants with high physical activity. The odds of 10-year CVD risk of at least 10% were higher in those with primary education or less (adjusted odds ratio 4·14; 95% CI 1·25-13·68; p=0·021) or with secondary education (4·04, 1·15-14·10; p=0·028) versus participants educated to at least college status; in urban residents (2·03, 1·26-3·27; p=0·0031) versus rural residents; in those who were retired or unable to work (2·01, 1·15-3·49; p=0·014) versus those who were working or unemployed but able to work; and in those with low physical activity (2·35, 1·47-3·76; p<0·0001) versus those with high activity. Communities living in climates with higher water vapour pressure had higher overall 10-year CVD risk than those with lower water vapour pressure (β coefficient percentage 1·56%, 95% CI 0·68 to 2·43; p<0·0001), whereas those in hotter climates had lower risk than those in cooler climates (-0·07, -0·14 to -0·01; p=0·023).

Interpretation: This study shows variations in CVD risk with individual-level and community-level factors in the Ethiopian population in 2015. Priority populations for the assessment of CVD risk and early intervention include individuals in urban areas, those who are retired or unable to work, individuals with low physical activity and lower education, as well as communities experiencing inherently higher water vapour pressure and cooler climates.

Funding: None.