Effects of Smoking on Subjective and Objective Measures of Pain Intensity, Functional Impairment and Health-related Quality of Life in Lumbar Degenerative Disc Disease

Abstract

BACKGROUND Numerous studies assessed the effects of smoking on lumbar degenerative disc disease (DDD); they focused on patient-reported outcomes measures (PROMs) and yielded conflicting results. METHODS In this two-center study on consecutive patients receiving surgical treatment for lumbar DDD, subjective functional impairment (SFI) in terms of PROMs including visual analog scale back and leg pain, Roland-Morris, Oswestry Disability Index, Euro-Qol, Short Form-12 physical component summary was determined at baseline, three days, six weeks, six months and one year postoperatively. Age- and sex-adjusted T-scores of objective functional impairment (OFI) were determined using the Timed Up and Go (TUG) test up to six weeks postoperatively. The responder status was defined by the minimal clinically important difference. RESULTS A total of n=375 patients were analyzed (n=96 (25.6%) smokers and n=279 (74.4%) non-smokers). SFI on any of the PROMs before treatment was similar in smokers and non-smokers. Smokers were more likely to have OFI in univariate logistic regression analysis (95% confidence interval (95%CI) 1.31-3.37, p=0.002). In multivariate analysis, however, this relationship became insignificant (95%CI 0.85-2.38, p=0.184). The smoking status had no predictive capacity on the six-week SFI or OFI responder status, and there were no differences in any of the PROMs until the one-year follow-up. CONCLUSIONS PROMs measuring SFI for pain intensity, functional impairment and health-related quality of life were similar in smokers and non-smokers before surgery for lumbar DDD, as well as postoperatively. The smoking status has negligible impact on the TUG test, which appears to be a robust assessment tool for OFI.