Clinically Significant Outcome Scores in Orthopaedic Sports Medicine Shoulder and Knee Surgery Are Increasing in Prevalence but Often Reported Incorrectly

Abstract

Purpose: To study the prevalence and quality of application of minimal clinically important difference (MCID), substantial clinical benefit (SCB), patient-acceptable symptomatic state (PASS), and maximum outcome improvement (MOI), reported in the orthopaedic sports medicine knee and shoulder literature in recent years and to bring awareness of proper use of such metrics.

Methods: A literature review of all shoulder and knee articles published from the American Journal of Sports Medicine (AJSM), Journal of Shoulder and Elbow Surgery (JSES), and Arthroscopy from 2016 to 2020 was performed, specifically investigating whether MCID, SCB, PASS, or MOI were used or reported. Additionally, the way these metrics were reported and interpreted was recorded.

Results: Out of 5,039 studies, 889 shoulder and knee studies met the inclusion criteria. Overall, 16.7% reported either MCID, PASS, or SCB. MCID was the most reported across all 3 journals. MCID was reported 12.4% of the time throughout the 5 years. PASS was reported 3.2% and SCB 1.1% of the time over the 5 years. MOI was not reported by any of the journals during this period. There was a statistically significant increase in MCID reporting in 2 of the 3 journals over the 5-year course, Arthroscopy (P = .02) and AJSM (P = .05). There was no statistically significant increase in PASS or SCB reporting rates in all 3 journals. Only 39.1% of studies reported MCID correctly (i.e., defined as the number of individual patients meeting MCID/total patients in the study).

Conclusions: This study shows an increasing trend in the use of clinically significant outcome metrics, such as MCID, for interpretation of patient-reported outcomes; however, these individual metrics are often not being used on the individual level and subsequently not reported accurately. We recommend determining whether the specific metric met the threshold per individual patient and then reporting those as a percentage of the sample population to achieve the full potential of these metrics and translate them accurately across various studies.

Clinical relevance: As the usage of clinically significant outcome metrics rises, so does the need for accurate reporting. These findings will encourage future studies to follow a more standardized format.