Study objective: To describe the relationship between cigarette smoking and quality of life (QOL) among lung cancer survivors as measured by the lung cancer symptom scale (LCSS).
Design and setting: The LCSS was mailed to eligible patients (1,506 patients) between 1999 and 2002. LCSS scores (total and individual QOL components) were compared among different groups of cigarette smokers via univariate independent group testing and multivariate linear models. The modeling process examined group differences adjusted for age, gender, stage, and time of LCSS assessment. LCSS scores were transformed onto a scale of 0 to 100 points in which higher LCSS scores corresponded to a lower QOL. A 10-point difference between groups was defined a priori as being clinically significant.
Results: At the time of lung cancer diagnosis, 18% of the patients were never-smokers, 58% were former smokers, and 24% were current smokers. Among survey respondents completing the LCSS at follow-up assessment (1,028 respondents), the mean age was 65.2 years (SD, 10.8 years) and 45% were women. Thirty percent of baseline current smokers continued to smoke at the time of the follow-up assessment (ie, persistent smokers). The adjusted mean total LCSS scores for never-smokers and persistent smokers were 17.6 (SD, 4.02) and 28.7 (SD, 5.09), respectively (p < 0.0001). Seven of the individual LCSS QOL components (ie, appetite, fatigue, cough, shortness of breath, lung cancer symptoms, illness affecting normal activities, and overall QOL) were clinically and statistically (p < 0.001) different between never-smokers and persistent smokers. No clinically significant differences were noted for pain or hemoptysis. Former smokers had intermediate LCSS scores. No dose-response trends were observed between the number of packs of cigarettes smoked per day or the total number of pack-years smoked and the adjusted scores.
Conclusion: The hypothesized relationship between smoking status and QOL was supported by this correlational study. Our findings suggest that persistent cigarette smoking after a lung cancer diagnosis negatively impacts QOL scores.