Association of workplace and population characteristics with prevalence of hypertension among Brazilian industry workers: a multilevel analysis

BACKGROUND: Exposure to risk factors for hypertension may be influenced by the characteristics of the workplace, where workers spend most of their daily time. OBJECTIVES: To evaluate the association between features of the companies, particularly the presence of facilities to provide meals, and of population characteristics and the prevalence of hypertension, taking into account individual risk factors for hypertension. MATERIAL AND METHODS: This multilevel analysis was based on a cross-sectional study with individual and company data from the SESI (Serviço Social da Indústria–Social Service of Industries) study and population-based data from the national census statistics. Workers aged ≥15 years were randomly selected from small (20–99), medium (100–499) and large (≥500 employees) companies per state using multistage sampling. Logistic regression was used to analyse the association between hypertension and individual, workplace and population variables, with odds ratios (ORs; 95% CI) adjusted for three-level variables. RESULTS: 4818 Workers from 157 companies were interviewed and their blood pressure, weight and height were measured. Overall, 77% were men, aged 35.4 ±10.7 years, with 8.7 ±4.1 years of schooling and mostly worked in companies with a staff canteen (66%). Besides individual characteristics—being male, ageing, low schooling, alcohol abuse and higher BMI—a workplace with no staff canteen (OR=1.28; 95% CI 1.08 to 1.52), small companies (OR=1.31; 95% CI 1.07 to 1.60) and living in cities with higher economic inequality (OR=1.47; 95% CI 1.23 to 1.76) were associated with a higher risk for hypertension. CONCLUSION: Among Brazilian workers, the prevalence of hypertension is associated with individual risk factors, lack of a canteen at the workplace, small companies and higher economic inequalities of cities. These three-level characteristics help to interpret differences in the prevalence of hypertension between regions or countries.