title: Prediction of walking disability by disease-related factors in patients with rheumatoid arthritis.
abstract: OBJECTIVE
  To investigate the relationship between disease-related factors and walking disability in different phases of rheumatoid arthritis; and to predict future walking disability in rheumatoid arthritis, using disease-related factors assessed 2 years after diagnosis.
  
  
  METHODS
  A cohort of 848 newly diagnosed patients with rheumatoid arthritis was followed up for a maximum of 8 years. Walking disability and several disease-related and demographic factors were recorded during follow-up. A logistic regression model was used to study associations between walking disability and these factors at different time points. A multilevel logistic regression model for longitudinal data was used to predict walking disability during follow-up from potential predictors at year 2.
  
  
  RESULTS
  Global pain and disease activity were consistently related to walking disability at almost every time point. Significant predictors of future walking disability were: walking disability, knee pain, global pain, the passage of time during follow-up, and age.
  
  
  CONCLUSIONS
  Global pain and disease activity are related to walking disability during the first 8 years of RA. Walking disability, knee pain, and global pain at 2 years follow-up predict walking disability later in the disease. In addition, the risk for walking disability increases during the disease process and with higher age at diagnosis.
authors.affiliation: Jan van Breemen Institute, Center for Rheumatology and Rehabilitation, Jan van Breemenstraat 2, 1056 AB Amsterdam, The Netherland. m.vd.leeden@janvanbreemen.nl
authors.forename: Marike
authors.initials: M
authors.lastname: van der Leeden
authors.forename: Rutger
authors.initials: R
authors.lastname: Dahmen
authors.forename: Jennie
authors.initials: J
authors.lastname: Ursum
authors.forename: Leo D
authors.initials: LD
authors.lastname: Roorda
authors.forename: Dirkjan
authors.initials: D
authors.lastname: van Schaardenburg
authors.forename: Dirk L
authors.initials: DL
authors.lastname: Knol
authors.forename: Joost
authors.initials: J
authors.lastname: Dekker
authors.forename: Martijn P M
authors.initials: MP
authors.lastname: Steultjens
mesh_terms: D000328:Adult; D001172:Arthritis, Rheumatoid / Q000175:diagnosis* / Q000503:physiopathology; D015331:Cohort Studies; D004185:Disability Evaluation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D011379:Prognosis; D016138:Walking / Q000502:physiology