STEPS Survey of non-communicable diseases, mental health, oral health and injuries in Tanzania: methodology and study population

Abstract

Introduction: The burden of non-communicable diseases (NCDs) remains a public health concern in Tanzania, contributing to high morbidity and mortality. STEPS surveys conducted in 2011 and 2012 in Zanzibar and mainland Tanzania indicated a high prevalence of NCDs and related risk factors. This paper describes the methodology of the 2023 STEPS survey on NCD risk factors and presents the baseline characteristics of the survey respondents. 

Objectives: The survey was conducted to provide nationally representative data on the NCD risk factors in Tanzania, Mainland, and Zanzibar

Methods: The survey was a household-based study that employed a three-stage cluster sampling design. The target population consisted of all individuals, both women and men, aged 18 to 69 years, who were usual residents of the selected households. The Tanzania Population and Housing Census 2022 was used as the sampling frame for the 2022/2023 STEPS survey. The overall estimated sample size was 4,320 respondents (Mainland = 3,780 and Zanzibar = 540). Data were collected on the levels of major NCD risk factors, including physical inactivity, unhealthy dietary practices, smoking, harmful alcohol consumption, depression, and overweight/obesity, using the standardized WHO STEPS methodology. Data were collected electronically using Open Data Kit (ODK)-based eSTEPS software. The survey was conducted from September 2022 to September 2023. Ethical approval to conduct the study was obtained from the National Health Research Ethics Committee for Tanzania Mainland, the Zanzibar Health Research Ethics Committee, and the Second Vice President's Office for Zanzibar.

Results: Estimates of NCD prevalence and associated risk factors and determinants will be reported.

Conclusion: This survey highlighted the prevalence estimates of hypertension, diabetes, mental health issues and depression, road traffic injuries, non-road traffic accidents, and the burden of cardiovascular risks in Tanzania. Risk factor analysis identified and quantified common behaviours and conditions that increase the likelihood of developing non-communicable diseases. Analysing these risk factors will help identify high-risk groups and inform targeted prevention strategies.