High Rate of Overlapping Question Content Among Commonly Used Patient-Reported Outcome Measurements for Anterior Cruciate Ligament Injury

PURPOSE: To precisely compare the questions and content between the most commonly cited knee-specific patient-reported outcome measurements (PROs) for anterior cruciate ligament (ACL) injury. METHODS: A literature review through Medline from November 1, 2018, to November 1, 2020, was performed to find the most cited knee-specific PROs for assessment of ACL injuries. Each question was then classified as 1) identical, similar, or unique; 2) pertaining to 1 of 6 domains (pain, symptoms, functional activities, occupational activities, sports/recreation, and quality of life). The PROs were then compared to each other to assess question overlap and domain coverage. RESULTS: A total of 133 questions were analyzed from the seven most common PROs: International Knee Documentation Committee (IKDC) form, Knee Injury and Osteoarthritis Outcome Score (KOOS), Lysholm Knee Scoring Scale, Tegner Activity Scale, Marx Scale, Knee Outcome Survey (KOS), and Cincinnati Knee Rating System (CKRS). The total distribution of identical (31.6%), similar (31.6%), and unique (36.8%) questions was found to be relatively even. However, this distribution varied within each PRO. KOS and Lysholm had the highest percentages of identical questions (64% and 62.5%, respectively). KOOS had the highest number of unique questions (26/42, 61.9%), while Tegner held the highest percentage (11/16, 68.8%). Sports/recreation was the only domain assessed by all PROs. CONCLUSION: Nearly two-thirds of questions overlap between the commonly used PROs for ACL injury. Although sports/recreation is assessed by all PROs, each has its own pattern of coverage across this and other domains. LEVEL OF EVIDENCE: IV, cross-sectional study.