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 Instability-Return to Sport After Injury (SIRSI) scale and determine the predictive validity of the short version compared with the original form.

Methods: This study included patients who underwent an arthroscopic Bankart repair or open Latarjet procedure between 2017 and 2019. One group was used for the SIRSI scale-reduction process, and a second group was used to test the predictive validity of the proposed short SIRSI scale. The Cronbach α value was used to evaluate internal consistency. Validity was determined by calculating the Pearson correlation coefficient with the Western Ontario Shoulder Instability Index scale. Predictive validity was assessed using receiver operating characteristic (ROC) curve statistics.

Results: A total of 158 patients participated in the scale-reduction process, and 137 patients participated in the predictive-validation process. The SIRSI scale was successfully reduced to a 5-item scale constructed by 1 underlying factor accounting for 60% of the variance. The short version showed good internal consistency (Cronbach α = 0.82) and was highly correlated with the Western Ontario Shoulder Instability Index scale and the long version. The short SIRSI scores were significantly different between patients who returned to sports and those who did not. The SIRSI scale had excellent predictive ability for return-to-sport outcomes (area under ROC curve of 0.84 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.