Association Between Cigarette Smoking and Functional Health Status: An Office-Based
Survey of Primary Care Patients
Thomas Franck
Preceptors: Stephen Rothemich, M.D. and Bob Johnson, Ph.D.
Advisor: Paul Mazmanian, Ph.D.
Objective: The purpose of this study was to determine the relationship between cigarette smoking and quality of life in primary care patients in the outpatient setting. More specifically, the aim of this study was to test the hypothesis that cigarette smoking is associated decreased levels of self-perceived functional health status, both in the physical realm and the emotional realm.
Methods: Design: This study was a cross-sectional survey of 3,995 patients visiting five primary care practices. Patients completed a self-administered, structured questionnaire which contained the SF-367 (Medical Outcomes Trust, Boston, MA) functional health status instrument as well as questions about demographics and tobacco use.
Setting: The study involved five independent family practice clinics located in Richmond, Virginia and the surrounding metropolitan area. The practices are participants in a practice-based research network developed by the Department of Family Practice at Virginia Commonwealth University.
Main Outcome Measure: The main outcome was functional health status as measured by the SF-36, including scores on eight domains and two summary measures (physical composite score and mental composite score).
Results: With respect to current smoking status, the unadjusted functional status scores were significantly lower in the current smokers than in the nonsmokers for each of the 8 domains and 2 summary measures of the SF-36 (p <=0.002). After adjusting for practice site and potential demographic confounders using multiple regression, these differences diminished and even lost statistical significance (p>=0.05) for 2 of the physical domains and the physical composite score; but they remained statistically significant for all of the mental domains and the mental composite score (p < 0.001). Comparing ever-smokers with never-smokers gave results similar to the above, with the following exceptions: after adjustment, the difference between ever-smokers and never-smokers remained significant for physical composite score (p = 0.007) but lost significance for the domain of emotional role limitations (p = 0.063).
Conclusions: Cigarette smoking is associated with impaired physical and mental functional health status among primary care patients, even after factoring out differences in demographics and practice sites. This association appears to be stronger and broader across the mental domains than the physical domains. The exact meaning of this association is unclear and a cause-effect relationship cannot be concluded from this cross-sectional study; a longitudinal study applied to the same setting as above is suggested.
