title: Prognosis of Pain and Physical Functioning in Patients With Knee Osteoarthritis: A Systematic Review and Meta-Analysis.
abstract: OBJECTIVE
  To systematically summarize the literature on the course of pain in patients with knee osteoarthritis (OA), prognostic factors that predict deterioration of pain, the course of physical functioning, and prognostic factors that predict deterioration of physical functioning in persons with knee OA.
  
  
  METHODS
  A search was conducted in PubMed, CINAHL, Embase, Psych-INFO, and SPORTDiscus up to January 2014. A meta-analysis and a qualitative data synthesis were performed.
  
  
  RESULTS
  Of the 58 studies included, 39 were of high quality. High heterogeneity across studies (I(2)  >90%) and within study populations (reflected by large SDs of change scores) was found. Therefore, the course of pain and physical functioning was interpreted to be indistinct. We found strong evidence for a number of prognostic factors predicting deterioration in pain (e.g., higher knee pain at baseline, bilateral knee symptoms, and depressive symptoms). We also found strong evidence for a number of prognostic factors predicting deterioration in physical functioning (e.g., worsening in radiographic OA, worsening of knee pain, lower knee extension muscle strength, lower walking speed, and higher comorbidity count).
  
  
  CONCLUSIONS
  Because of high heterogeneity across studies and within study populations, no conclusions can be drawn with regard to the course of pain and physical functioning. These findings support current research efforts to define subgroups or phenotypes within knee OA populations. Strong evidence was found for knee characteristics, clinical factors, and psychosocial factors as prognostics of deterioration of pain and physical functioning.
authors: Amsterdam Rehabilitation Research Centre, Reade, Amsterdam, The Netherlands.
authors: Mariëtte
authors: M
authors: de Rooij
authors: Amsterdam Rehabilitation Research Centre, Reade, and VU University Medical Centre, EMGO Institute, Amsterdam, The Netherlands.
authors: Marike
authors: M
authors: van der Leeden
authors: VU University Medical Centre, EMGO Institute, Amsterdam, The Netherlands.
authors: Martijn W
authors: MW
authors: Heymans
authors: Amsterdam Rehabilitation Research Centre, Reade, Amsterdam, The Netherlands.
authors: Jasmijn F M
authors: JF
authors: Holla
authors: University of Jyväskylä and Jyväskylä Central Hospital, Jyväskylä, Finland.
authors: Arja
authors: A
authors: Häkkinen
authors: VU University Medical Centre, EMGO Institute, Amsterdam, The Netherlands.
authors: Willem F
authors: WF
authors: Lems
authors: Amsterdam Rehabilitation Research Centre, Reade, Amsterdam, The Netherlands.
authors: Leo D
authors: LD
authors: Roorda
authors: University Medical Centre Utrecht, Utrecht, The Netherlands.
authors: Cindy
authors: C
authors: Veenhof
authors: University of Alberta, Edmonton, Alberta, Canada.
authors: Diana C
authors: DC
authors: Sanchez-Ramirez
authors: VU University Medical Centre, EMGO Institute, Amsterdam, The Netherlands.
authors: Henrica C W
authors: HC
authors: de Vet
authors: VU University Medical Centre, EMGO Institute, Amsterdam, The Netherlands.
authors: Joost
authors: J
authors: Dekker
mesh_terms: D018771:Arthralgia / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D001696:Biomechanical Phenomena; D018450:Disease Progression; D005260:Female; D006304:Health Status; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008297:Male; D020370:Osteoarthritis, Knee / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D010147:Pain Measurement; D010641:Phenotype; D011379:Prognosis; D011859:Radiography; D012307:Risk Factors