Urban-rural and gender differences in tobacco and alcohol use, diet and physical activity among young black South Africans between 1998 and 2003.

BACKGROUND: Non-communicable chronic diseases (NCDs) have increased in South Africa over the past 15 years. While these usually manifest during mid-to-late adulthood, the development of modifiable risk factors that contribute to NCDs are usually adopted early in life.

OBJECTIVE: To describe the urban-rural and gender patterns of NCD risk factors in black adolescents and young adults (15- to 24-year-olds) from two South African Demographic and Health Surveys conducted 5 years apart.

DESIGN: An observational study based on interviews and measurements from two cross-sectional national household surveys. Changes in tobacco and alcohol use, dietary intake, physical inactivity, and overweight/ obesity among 15- to 24-year-olds as well as urban-rural and gender differences were analysed using logistic regression. The 'Surveyset' option in Stata statistical software was used to allow for the sampling weight in the analysis.

RESULTS: Data from 3,186 and 2,066 black 15- to 24-year-old participants in 1998 and 2003, respectively, were analysed. In males, the prevalence of smoking (1998: 21.6%, 2003: 19.1%) and problem drinking (1998: 17.2%, 2003: 15.2%) were high and increased with age, but in females were much lower (smoking - 1998: 1.0%, 2003: 2.1%; problem drinking - 1998: 4.2%, 2003: 5.8%). The predominant risk factors in females were overweight/obesity (1998: 29.9%, 2003: 31.1%) and physical inactivity (2003: 46%). Urban youth, compared to their rural counterparts, were more likely to smoke (odds ratio (OR): 1.39, 95% confidence interval (CI): 1.09-1.75), have high salt intake (OR: 1.75, 95% CI: 1.12-2.78), be overweight/obese (OR: 1.39, 95% CI: 1.14-1.69), or be physically inactive (OR: 1.45, 95% CI: 1.12-1.89). However, they had lower odds of inadequate micronutrient intake (OR: 0.46, 95% CI 0.34-0.62), and there was no overall significant urban- rural difference in the odds for problem drinking but among females the odds were higher in urban compared to rural females.

CONCLUSION: Considering that the prevalence of modifiable NCD risk factors was high in this population, and that these may persist into adulthood, innovative measures are required to prevent the uptake of unhealthy behaviours, and regular surveillance is needed.