title: Women in Charnley class C fail to improve in mobility to a higher degree after total hip replacement.
abstract: BACKGROUND
  The Charnley comorbidity classification organizes patients into 3 classes: (A) 1 hip involved, (B) 2 hips involved, and (C) other severe comorbidities. Although this simple classification is a known predictor of health-related quality of life (HRQoL) after total hip replacement (THR), interactions between Charnley class, sex, and age have not been investigated and there is uncertainty regarding whether A and B should be grouped together.
  
  
  METHODS
  We selected a nationwide cohort of patients from the Swedish Hip Arthroplasty Register operated with THR due to primary osteoarthritis between 2008 and 2010. For estimation of HRQoL, we used the generic health outcome questionnaire EQ-5D of the EuroQol group. This consists of 2 parts: the EQ-5D index and the EQ VAS estimates. We modeled the EQ-5D index and the EQ VAS against the self-administered Charnley classification. Confounding was controlled for using preoperative HRQoL values, pain, and previous contralateral hip surgery.
  
  
  RESULTS
  We found that women in class C had a poorer EQ-5D outcome than men. This effect was mostly due to the fact that women failed to improve in the mobility dimension; only 40% improved, while about 50% of men improved. Age did not interact with Charnley class. We also found that the classification performed best without splitting or aggregating classes.
  
  
  CONCLUSIONS
  Our results suggests that the self-administered Charnley classification should be used in its full capacity and that it may be interesting to devote special attention to women in Charnley class C.
authors: Swedish Hip Arthroplasty Register , Gothenburg.
authors: Max
authors: M
authors: Gordon
authors: Paolo
authors: P
authors: Frumento
authors: Olof
authors: O
authors: Sköldenberg
authors: Meridith
authors: M
authors: Greene
authors: Göran
authors: G
authors: Garellick
authors: Ola
authors: O
authors: Rolfson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000145:classification* / Q000534:rehabilitation*; D015897:Comorbidity; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D051346:Mobility Limitation; D009043:Motor Activity; D015207:Osteoarthritis, Hip / Q000453:epidemiology / Q000534:rehabilitation* / Q000601:surgery*; D011446:Prospective Studies; D011788:Quality of Life; D020127:Recovery of Function; D012042:Registries; D012720:Severity of Illness Index; D017678:Sex Distribution; D013548:Sweden / Q000453:epidemiology