Association between household air pollution and neonatal mortality: an analysis of Annual Health Survey results, India.

ABSTRACT

Background: In India, household air pollution (HAP) is one of the leading risk factors contributing to the national burden of disease. Estimates indicate that 7.6% of all deaths in children aged under 5 years in the country can be attributed to HAP. This analysis attempts to establish the association between HAP and neonatal mortality rate (NMR). Methods: Secondary data from the Annual Health Survey, conducted in 284 districts of nine large states covering 1 404 337 live births, were analysed. The survey was carried out from July 2010 to March 2011 (reference period January 2007 to December 2009). The primary outcome was NMR. The key exposure was the use of firewood/crop residues/cow dung as fuel. The covariates were sociodemographic factors (place of residence, literacy status of mothers, proportion of women aged less than 18 years who were married, wealth index); health-system factors (three or more antenatal care visits made during pregnancy; institutional deliveries; proportion of neonates with a stay in the institution for less than 24 h; percentage of neonates who received a check-up within 24 h of birth); and behavioural factors (initiation of breast feeding within 1 h). Descriptive analysis, with district as the unit of analysis, was performed for rural and urban areas. Bivariate and multivariable linear regression analysis was carried out to investigate the association between HAP and NMR. Results: The mean rural NMR was 42.4/1000 live births (standard deviation [SD] = 11.4/1000) and urban NMR was 33.1/1000 live births (SD=12.6/1000). The proportion of households with HAP was 92.2% in rural areas, compared to 40.8% in urban areas, and the difference was statistically significant (P < 0.001). HAP was found to be strongly associated with NMR after adjustment (β = 0.22; 95% confidence interval [CI] = 0.09 to 0.35) for urban and rural areas combined. For rural areas separately, the association was significant (β = 0.30; 95% CI = 0.13 to 0.45) after adjustment. In univariable analysis, the analysis showed a significant association in urban areas (β = 0.23; 95% CI = 0.12 to 2.34) but failed to demonstrate an association in multivariable analysis (β = 0.001; 95% CI = –0.15 to 0.15). Conclusion: Secondary data from district level indicate that HAP is associated with NMR in rural areas, but not in urban areas in India.