Secondhand smoke exposure and validity of self-report in low-income women and children in India

Abstract

Background: There is limited validation of self-reported measures for secondhand smoke (SHS) exposure in low- and middle-income countries. We evaluated the validity of standard self-reported measures among women and children in urban India. Methods: Structured questionnaires were administered, and household air and hair samples were analyzed for nicotine concentration. Results: In total, 141 households of 70 child and 71 adult participants were included. Air nicotine was detected in 72 (51%) homes, and 35 (75%) child and 12 (56%) adult participants had detectable hair nicotine. Correlation between air and hair nicotine was significant in children (r = 0.5; P = .0002) but not in adults (r = -0.1; P = .57). Poor correlation was found between self-reported measures of exposure and both air and hair nicotine. No questions were significantly correlated with hair nicotine, and the highest-magnitude correlation with air nicotine was for how often someone smoked inside for adults (r = 0.4; P = .10) and for home preparation of mishri (a smokeless tobacco product prepared for consumption by roasting) for children (r = 0.4; P = .39). The highest value for sensitivity by using air nicotine as the gold standard was for whether people smelled other families preparing mishri (47%; 95% confidence interval: 31-62) and prepared mishri in their own homes (50%; 95% confidence interval: 19-81). Conclusions: These results raise caution in using or evaluating self-reported SHS exposure in these communities. More appropriate questions for this population are needed, including mishri preparation as a source of SHS exposure.