title: Different hip and knee priority score systems: are they good for the same thing?
abstract: OBJECTIVE
  The aim of the present study was to compare two priority tools used for joint replacement for patients on waiting lists, which use two different methods.
  
  
  METHODS
  Two prioritization tools developed and validated by different methodologies were used on the same cohort of patients. The first, an IRYSS hip and knee priority score (IHKPS) developed by RAND method, was applied while patients were on the waiting list. The other, a Catalonia hip-knee priority score (CHKPS) developed by conjoint analysis, was adapted and applied retrospectively. In addition, all patients fulfilled pre-intervention the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Correlation between them was studied by Pearson correlation coefficient (r). Agreement was analysed by means of intra-class correlation coefficient (ICC), Kendall coefficient and Cohern kappa. The relationship between IHKPS, CHKPS and baseline WOMAC scores by r coefficient was studied.
  
  
  RESULTS
  The sample consisted of 774 consecutive patients. Pearson correlation coefficient between IHKPS and CHKPS was 0.79. The agreement study showed that ICC was 0.74, Kendall coefficient 0.86 and kappa 0.66. Finally, correlation between CHKPS and baseline WOMAC ranged from 0.43 to 0.64. The results according to the relationship between IHKPS and WOMAC ranged from 0.50 to 0.74.
  
  
  CONCLUSIONS
  Results support the hypothesis that if the final objective of the prioritization tools is to organize and sort patients on the waiting list, although they use different methodologies, the results are similar.
authors.affiliation: Research Unit, Hospital of Basurto, Bilbao, Bizkaia, Spain. antonio.escobarmartinez@osakidetza.net
authors.forename: Antonio
authors.initials: A
authors.lastname: Escobar
authors.forename: Jose Maria
authors.initials: JM
authors.lastname: Quintana
authors.forename: Mireia
authors.initials: M
authors.lastname: Espallargues
authors.forename: Alejandro
authors.initials: A
authors.lastname: Allepuz
authors.forename: Berta
authors.initials: B
authors.lastname: Ibañez
mesh_terms: D019644:Arthroplasty, Replacement, Hip; D019645:Arthroplasty, Replacement, Knee; D006801:Humans; D020380:Needs Assessment / Q000592:standards* / Q000706:statistics & numerical data; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013030:Spain; D014850:Waiting Lists