The Short, 5-Item Shoulder Instability–Return to Sport After Injury Score Performs as Well as the Longer Version in Predicting Psychological Readiness to Return to Sport

Abstract

Purpose: To reduce the length of the Shoulder InstabilityeReturn to Sport After Injury (SIRSI) scale and determine thepredictive validity of the short version compared with the original form. Methods: This study included patients whounderwent an arthroscopic Bankart repair or open Latarjet procedure between 2017 and 2019. One group was used forthe SIRSI scale-reduction process, and a second group was used to test the predictive validity of the proposed short SIRSIscale. The Cronbach a value was used to evaluate internal consistency. Validity was determined by calculating the Pearsoncorrelation coefficient with the Western Ontario Shoulder Instability Index scale. Predictive validity was assessed usingreceiver operating characteristic (ROC) curve statistics. Results: A total of 158 patients participated in the scale-reductionprocess, and 137 patients participated in the predictive-validation process. The SIRSI scale was successfully reduced to a5-item scale constructed by 1 underlying factor accounting for 60% of the variance. The short version showed goodinternal consistency (Cronbach a ¼ 0.82) and was highly correlated with the Western Ontario Shoulder Instability Indexscale and the long version. The short SIRSI scores were significantly different between patients who returned to sports andthose who did not. The SIRSI scale had excellent predictive ability for return-to-sport outcomes (area under ROC curve of0.84 for short version [95% confidence interval, 0.7-0.9] and 0.83 for long version [95% confidence interval, 0.7-0.9]).Conclusions: A valid 5-item, short version of the SIRSI scale was successfully developed in our patient population.The short version was found to be as robust as the long scale for discriminating and predicting return-to-sport outcomes.Level of Evidence: Level II, prospective cohort study.