Validity of self-reported adult secondhand smoke exposure

Exposure of adults to secondhand smoke (SHS) has immediate adverse effects on the cardiovascular system and causes coronary heart disease. The current study evaluated brief self-report screening measures for accurately identifying adult cardiology patients with clinically significant levels of SHS exposure in need of intervention.

A cross-sectional study conducted in a university-affiliated cardiology clinic and cardiology inpatient service.

Participants were 118 non-smoking patients (59% male, mean age=63.6 years, SD=16.8) seeking cardiology services.

Serum cotinine levels and self-reported SHS exposure in the past 24 h and 7 days on 13 adult secondhand exposure to smoke (ASHES) items.

A single item assessment of SHS exposure in one's own home in the past 7 days was significantly correlated with serum cotinine levels (r=0.41, p<0.001) with sensitivity ≥75%, specificity >85% and correct classification rates >85% at cotinine cut-off points of >0.215 and >0.80 ng/mL. The item outperformed multi-item scales, an assessment of home smoking rules, and SHS exposure assessed in other residential areas, automobiles and public settings. The sample was less accurate at self-reporting lower levels of SHS exposure (cotinine 0.05-0.215 ng/mL).

The single item ASHES-7d Home screener is brief, assesses recent SHS exposure over a week's time, and yielded the optimal balance of sensitivity and specificity. The current findings support use of the ASHES-7d Home screener to detect SHS exposure and can be easily incorporated into assessment of other major vital signs in cardiology.