title: Symptom Co-occurrences Associated with Smoking in Individuals with Relapsing-Remitting Multiple Sclerosis.
abstract: BACKGROUND
  The impact of tobacco on the multiple sclerosis (MS) disease process and symptoms is complex and not clearly understood. Tobacco may be used to self-treat some symptoms but also seems to intensify others. Studies to date have not characterized co-occurring symptoms (symptom patterns) and their association with tobacco use.
  
  
  METHODS
  This study describes tobacco use in patients with relapsing-remitting MS and associated symptoms and symptom co-occurrences. In this cross-sectional study, 101 participants with an average age of 43 years completed a survey adapted from the Behavioral Risk Factor Surveillance System and the revised MS-Related Symptom Checklist. Data reduction was performed using factor analysis on the 43 items of the checklist, and linear regression was used to detect associations between symptom clusters (factors) and smoking.
  
  
  RESULTS
  Using the factor analysis result, the linear regression analysis found that tobacco use is positively associated with co-occurring symptoms and symptoms of factor 1: Mental/Emotional (anxiety, loneliness, depression, and difficulty sleeping) and factor 4: Neuro/Autonomic (urinary).
  
  
  CONCLUSIONS
  Smoking is associated with patterns of symptoms. The study of MS and tobacco use over time will allow determination of the temporal pattern of tobacco use and MS symptoms.
authors.forename: Pamela
authors.initials: P
authors.lastname: Newland
authors.forename: Louise
authors.initials: L
authors.lastname: Flick
authors.forename: Hong
authors.initials: H
authors.lastname: Xian
authors.forename: Florian P
authors.initials: FP
authors.lastname: Thomas