Escobar, AntonioBilbao, AmaiaBertrand, Maria LMoreta, JesúsFroufe, Miquel AColomina, JordiMartınez-Cruz, OlgaPerera, Robert ARiddle, Daniel L2023-02-092023-02-092021-03-29http://hdl.handle.net/10668/17422To test the validity of a second-generation appropriateness system in a cohort of patients undergoing total knee arthroplasty (TKA). We applied the RAND/UCLA Appropriateness Method to derive our second-generation system and conducted a prospective study of patients diagnosed with knee osteoarthritis in eight public hospitals in Spain. Main outcome questionnaires were the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Short-Form-12 (SF-12), and the Knee Society Score satisfaction scale (KSS), completed before and 6 months after TKA. Baseline, changes from baseline to 6 months (journey outcome), and 6-month scores (destination outcome) were compared according to appropriateness category. Percentage of patients attaining the minimal clinically important difference (MCID) and responders according to Outcome Measures in Rheumatology-Osteoarthritis Research Society (OMERACT-OARSI) criteria were also reported. A total of 282 patients completed baseline and 6-month questionnaires. Of these, 142 (50.4%) were classified as Appropriate, 90 (31.9%) as Uncertain, and 50 (17.7%) as Inappropriate. Patients classified as Appropriate had worse preoperative pain, function, and satisfaction (p The validity of our second-generation appropriateness system was generally supported. The findings highlight a critical issue in TKA healthcare: whether TKA appropriateness should be driven by the extent of improvement, by patient final state, or by both.enAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/AppropriatenessKneeOsteoarthritisOutcome measuresQuality of lifeSurgeryAgedArthroplasty, Replacement, KneeFemaleHumansKnee JointMaleMiddle AgedOsteoarthritis, KneeOutcome Assessment, Health CarePatient SatisfactionProspective StudiesQuality Assurance, Health CareQuality of LifeSpainSurveys and QuestionnairesTime FactorsTreatment Outcomeresearch article33781327open access10.1186/s13018-021-02371-z1749-799XPMC8006353https://josr-online.biomedcentral.com/counter/pdf/10.1186/s13018-021-02371-zhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC8006353/pdf