Validation of a Respiratory Symptom Questionnaire in Adolescent Smokers.

Cigarette smoking remains one of the world’s leading causes of premature death. More than 5 million smokers die every year from smoking-related disease.1 Most smokers began smoking in adolescence, with 88% of current smokers reporting that they began smoking before age 18.1 Thus, adolescence is a crucial time in the development of smoking behavior. Adolescent smokers exhibit significant withdrawal symptoms and other evidence of nicotine dependence despite a tendency for adolescents to be lighter and more intermittent smokers.2–7 In addition to dependence and withdrawal, smoking also creates physical symptoms, particularly respiratory issues such as cough and production of phlegm.8 Evidence indicates that adolescent smokers show decreased lung function as well as decreased gain in expected lung function over time, and adolescent smokers are at risk for developing chronic cough and production and expulsion of phlegm.9–13 Daily adolescent smokers are also more likely to perceive their own general health - including respiratory health - to be poorer when compared to peers who have never tried cigarettes, and to endorse more health complaints in general.14,15 Therefore, even at this early stage, the health of adolescent smokers begins to diverge from their non-smoking peers. Thus, tracking and understanding adolescents’ respiratory symptoms, and in particular their smoking-related respiratory symptoms, is an important part of characterizing the sequelae of smoking in this population. For adolescents and adult smokers, the landscape of available products is also changing rapidly. Emerging tobacco products are changing our understanding of nicotine and tobacco use. E-cigarettes, dissolvable tobacco products, and very low nicotine cigarettes all deliver nicotine in very different ways, and current smokers may shift their behavior to these products in part due to concerns over health. Adult e-cigarette users, in particular, report that they switch from traditional to electronic cigarettes in part due to respiratory issues, and that e-cigarettes result in decreased cough and breathing issues compared to traditional cigarettes.16 However, the extent to which these products may affect respiratory symptoms in adolescents is unclear. A validated measure of respiratory symptoms in adolescent smokers would allow for harmonization of data across studies tracking the health effects of these new products, and allow for comparison of symptom alleviation in both adolescents and adults. In turn, this type of research could inform policies regarding the regulation of tobacco products. One self-report instrument that has been used widely for measuring general respiratory symptoms in adults is the American Thoracic Society Questionnaire (ATSQ).17 The ATSQ is an 8-item querying coughing, wheezing, phlegm production, shortness of breath, and other symptoms. The ATSQ has been used less frequently to assess respiratory symptoms specifically as they relate to smoking; however, several relevant studies have been conducted. In young adults, smokers have been found to endorse 5 of 8 distinct symptoms on average, and ATSQ scores have been shown to decrease significantly following 2 weeks of smoking abstinence, indicating criterion validity.18,19 In adolescents, a small study of 28 smokers and 18 nonsmokers showed that ATSQ scores were higher among smokers, and that smokers endorsed specific items (morning cough, shortness of breath when walking and during exercise, and getting tired easily) at significantly higher rates than nonsmokers.10 The ATSQ also has been reported to correlate with a single-item self-report of cigarettes per day in adolescent smokers.7 To date the ATSQ has not been throughly validated in a sample of adolescent smokers, and its psychometric properties and relationship to biomarkers of smoking have not been reported. Furthermore, the relationship between the ATSQ and validated measures of smoking behavior and dependence in adolescents has not been explored. The aim of the current study was to extend the limited literature on ATSQ scores in this population by validating the ATSQ in 2 studies of adolescents. We hypothesized that respiratory symptoms, as indexed by the ATSQ, would be reported at higher rates and with greater severity among smokers compared to matched nonsmokers, and that higher ATSQ scores would be associated with higher rates of smoking (indexed by self-report and biomarkers) and dependence. The ATSQ is a comparatively short, easily self-administered questionnaire. If validated, it would provide a practical instrument for assessing baseline levels of respiratory symptoms related to smoking in adolescents, and for evaluating changes in symptoms as a result of changes in product use patterns or cessation.