Clustering of chronic non-communicable disease risk factors among selected Asian populations: levels and determinants

Background: The major chronic non-communicable diseases (NCDs) operate through a cluster of common risk factors, whose presence or absence determines not only the occurrence and severity of the disease, but also informs treatment approaches. Primary prevention based on mitigation of these common risk factors through population-based programmes is the most cost-effective approach to contain the emerging epidemic of chronic NCDs. Objectives: This study was conducted to explore the extent of risk factors clustering for the major chronic NCDs and its determinants in nine INDEPTH Health and Demographic Surveillance System (HDSS) sites of five Asian countries. Design: Data originated from a multi-site chronic NCD risk factor prevalence survey conducted in 2005. This cross-sectional survey used a standardised questionnaire developed by the WHO to collect core data on common risk factors such as tobacco use, intake of fruits and vegetables, physical inactivity, blood pressure levels, and body mass index. Respondents included randomly selected sample of adults (25-64 years) living in nine rural HDSS sites in Bangladesh, India, Indonesia, Thailand, and Vietnam. Results: Findings revealed a substantial proportion (> 70%) of these largely rural populations having three or more risk factors for chronic NCDs. Chronic NCD risk factors clustering was associated with increasing age, being male, and higher educational achievements. Differences were noted among the different sites, both between and within country. Conclusions: Since there is an extensive clustering of risk factors for the chronic NCDs in the populations studied, the interventions also need to be based on a comprehensive approach rather than on a single factor to forestall its cumulative effects which occur over time. This can work best if it is integrated within the primary health care system and the HDSS can be an invaluable epidemiological resource in this endeavor.