Secondhand Smoke: Prevalence, Validation and Effects

The US Surgeon General has reported that secondhand smoke (SHS) exposure has deleterious health effects. However, individuals are frequently unaware of their SHS exposure and well validated self-report measures are not readily available. The aim of this study is to validate self-reported SHS exposure by comparing reported responses with salivary cotinine and hair nicotine levels. This study is currently in its pilot phase. A telephone interview assessing a range of SHS exposure sources, respiratory symptoms and quality of life as measured by the EuroQol-5D has been completed in 100 self-reported non-smokers recruited from the Florida 2010 Behavioral Risk Factor Surveillance System Study. Following the interview, each participant was asked to mail a hair and saliva sample to the research office in the prepaid envelope provided. Participants were re-interviewed and re-sampled in order to determine test-retest reliability. Average self-reported secondhand smoke exposure time is 2.18 hours/day. Respiratory symptom questions based on the previous 30 days demonstrated good reliability; weighted kappa statistics ranged from 0.40-0.77. Twelve-month history of respiratory disorders and EQ5D measures also exhibited good reliability with weighted kappa statistics ranging from 0.54-1.00 and 0.50-0.71 respectively.Results indicate that test-retest reliability of SHS exposure, respiratory symptom and EQ-5D measures meet established standards of validity for survey research. The next critical phase of the pilot will be to correlate exposure, disease and quality of life measures with biomarkers of SHS exposure to establish a short and valid protocol for assessing exposure in population-based studies where collection of biological samples is unfeasible.