An economic analysis of persons with prolonged cough in rural northern Vietnam.

SETTING: Epidemiological surveillance in the Bavi district, northern Vietnam. OBJECTIVE: To compare the prevalences of prolonged cough across socio-economic groups defined by income, expenditure and official classification. To investigate inequalities using the Illness Concentration Index. DESIGN: Interviews in 11,547 randomly selected households with 35,832 persons aged 15 years or more. Prolonged cough was identified in 559 persons (1.5%). RESULTS: Differences between cough prevalences were found for all socio-economic indicators, but were less clear for expenditure. Lower economic groups reported higher prevalences than higher groups, and prevalences were higher among the elderly. Male was similar to female prevalence. The illness gap between the poor and rich was wider for men. The Illness Concentration Index confirmed these findings. CONCLUSION: Inequalities were found when using both different socio-economic indicators and different analysis approaches.