title: Effects of Smoking on Subjective and Objective Measures of Pain Intensity, Functional Impairment, and Health-Related Quality of Life in Lumbar Degenerative Disk Disease.
abstract: BACKGROUND
  Numerous studies assessed the effects of smoking on lumbar degenerative disk disease (DDD); they focused on patient-reported outcome measures (PROMs) and yielded conflicting results.
  
  
  METHODS
  In this 2-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-5D, and a Short-Form 12 physical component summary was determined at baseline, 3 days, 6 weeks, 6 months, and 1 year postoperatively. Age- and sex-adjusted T-scores of objective functional impairment (OFI) were determined using the Timed Up and Go test up to 6 weeks postoperatively. The responder status was defined by the minimal clinically important difference.
  
  
  RESULTS
  We analyzed 375 patients (n = 96 [25.6%] smokers and n = 279 [74.4%] nonsmokers). SFI on any of the PROMs before treatment was similar in smokers and nonsmokers. Smokers were more likely to have OFI in univariate logistic regression analysis (95% confidence interval 1.31-3.37, P = 0.002). In multivariate analysis, however, this relationship became insignificant (95% confidence interval 0.85-2.38, P = 0.184). The smoking status had no predictive capacity on the 6-week SFI or OFI responder status, and there were no differences in any of the PROMs until the 1-year follow-up.
  
  
  CONCLUSIONS
  PROMs measuring SFI for pain intensity, functional impairment, and health-related quality of life were similar in smokers and nonsmokers before surgery for lumbar DDD, as well as postoperatively. The smoking status has negligible impact on the Timed Up and Go test, which appears to be a robust assessment tool for OFI.
authors.affiliation: Department of Neurosurgery, Cantonal Hospital, St. Gallen, Switzerland. Electronic address: holger.joswig@gmail.com.
authors.forename: Holger
authors.initials: H
authors.lastname: Joswig
authors.affiliation: Department of Neurosurgery and Faculty of Medicine, University Hospital, Geneva, Switzerland.
authors.forename: Martin N
authors.initials: MN
authors.lastname: Stienen
authors.affiliation: Department of Neurology, School of Medicine and Public Health, University of Newcastle, Callaghan, Australia.
authors.forename: Nicolas R
authors.initials: NR
authors.lastname: Smoll
authors.affiliation: Department of Neurosurgery and Faculty of Medicine, University Hospital, Geneva, Switzerland.
authors.forename: Marco V
authors.initials: MV
authors.lastname: Corniola
authors.affiliation: Department of Neurosurgery, Cantonal Hospital, St. Gallen, Switzerland.
authors.forename: Ivan
authors.initials: I
authors.lastname: Chau
authors.affiliation: Department of Neurosurgery and Faculty of Medicine, University Hospital, Geneva, Switzerland.
authors.forename: Karl
authors.initials: K
authors.lastname: Schaller
authors.affiliation: Department of Neurosurgery, Cantonal Hospital, St. Gallen, Switzerland.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Hildebrandt
authors.affiliation: Department of Neurosurgery and Faculty of Medicine, University Hospital, Geneva, Switzerland.
authors.forename: Oliver P
authors.initials: OP
authors.lastname: Gautschi
mesh_terms: D000203:Activities of Daily Living; D015984:Causality; D015897:Comorbidity; D004651:Employment / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D055959:Intervertebral Disc Degeneration / Q000453:epidemiology* / Q000523:psychology / Q000601:surgery*; D008159:Lumbar Vertebrae / Q000601:surgery; D008297:Male; D010146:Pain / Q000453:epidemiology* / Q000517:prevention & control* / Q000523:psychology; D010147:Pain Measurement / Q000379:methods / Q000706:statistics & numerical data*; D015995:Prevalence; D011788:Quality of Life / Q000523:psychology*; D012307:Risk Factors; D012720:Severity of Illness Index; D012907:Smoking / Q000453:epidemiology* / Q000523:psychology; D013557:Switzerland / Q000453:epidemiology; D016896:Treatment Outcome
keywords: Lumbar degenerative disk disease; Objective functional impairment; Patient-reported outcome measures; Smoking; Subjective functional impairment; Timed Up and Go test