The PROMIS®-Plus-Osteoarthritis of the Knee (OAK) Profile Measure integrates generic and condition-specific content to enhance relevance and efficiency.

Abstract

OBJECTIVE\nThe Patient-Reported Outcomes Measurement Information System® (PROMIS®)-Plus-Osteoarthritis of the Knee (OAK) profile integrates universal PROMIS items with knee-specific items across 13 domains. We evaluated the psychometric properties of a subset of six domains associated with quality of life in people with OAK.\n\n\nSTUDY DESIGN AND SETTING\nIn a cross-sectional study of OAK patients (n=600), we estimated reliability using Pearson and Spearman correlations with Knee Injury and Osteoarthritis Outcome Score (KOOS) subscores and known-groups validity with PROMIS Global Health. Measure responsiveness was tested via paired t-tests in a longitudinal study (n=238), pre/post total knee replacement.\n\n\nRESULTS\nAcross the six domains, internal consistency reliability (Cronbach s alpha) was 0.77-0.95 and test-retest reliability (intraclass correlation coefficients) was ≥0.90. Correlations with KOOS subscores and PROMIS Global supported convergent and divergent validity. Known-groups validity testing revealed better scores in all domains for high vs. low global status groups, and knee-specific items added value in physical function and pain. All domains reflected (p<0.001) better health status scores at follow up.\n\n\nCONCLUSION\nThe six PROMIS-Plus-OAK profile domains demonstrated good psychometric characteristics. The measure integrates universal and knee-specific content to provide enhanced relevance, measurement precision and efficient administration for patient care and clinical research.