The role of context: neighbourhood characteristics strongly influence HIV risk in young women in Ndola, Zambia.

OBJECTIVES

To examine the effect of neighbourhood socioeconomic factors on human immunodeficiency virus (HIV) prevalence in young women (aged 15-24 years) in Zambia.

METHODS

Re-analysis of a cross-sectional, population-based sero-survey of nearly 2000 adults conducted in 1997/1998 in Ndola, Zambia. Neighbourhood-level socioeconomic status (SES) was defined using the availability of running water and electricity in addition to educational, employment and occupational characteristics of adults older than 24 years. Neighbourhood-level and individual-level risk factors were analysed with a multivariate multilevel logistic regression model using a hierarchical conceptual framework.

RESULTS

Young women living in neighbourhoods of lower or middle SES had higher HIV prevalences than those from higher SES neighbourhoods [lower SES: adjusted odds ratio (OR) 2.4, 95% confidence interval (CI) 1.3-4.5, middle SES: adjusted OR 2.4, 95% CI 1.3-4.7]. Young women living near a market were at increased risk of HIV infection (OR 2.9, 95% CI 1.4-5.9), while proximity to a health centre seemed protective (OR 0.4, 95% CI 0.2-1.0). When controlling for neighbourhood factors, better education was a risk factor for HIV infection (OR 1.5, 95% CI 1.0-2.1), although it was not significant in individual-level analysis.

CONCLUSIONS

Community-level factors are as important as individual-level factors in determining HIV infection in young women. Confining analyses to individual-level factors ignores the underlying causes and the modifying effect of context on individual behaviour and may even lead to different conclusions concerning the role of individual-level factors.