Validation of the Short Form Shoulder Instability Return to Sport After Injury (SIRSI-5) and Its Association With Return to Sports.

Background: Psychosocial readiness is thought to be important in establishing whether athletes are ready to return to sports (RTS). The 5-item Shoulder Instability-Return to Sport After Injury (SIRSI-5) is a short-form version of the 12-item questionnaire (SIRSI-12), which was validated in a postoperative Argentinian population and associated with psychological readiness to RTS. It is unknown if the SIRSI-5 is valid in surgical and nonsurgical populations in other geographic locations. Purpose: To establish whether the SIRSI-5 is valid in another population and if it is associated with RTS. Study Design: Cross-sectional study (diagnosis); Level of evidence, 3. Methods: A total of 79 participants with anterior shoulder instability managed operatively and nonoperatively were included. The SIRSI-5 and SIRSI-12 total scores were calculated. Intraclass correlation coefficients (ICCs) and Pearson correlations assessed convergent validity between SIRSI-5 and SIRSI-12. Logistic regression was used to assess the discrimination ability (leave-one-out cross-validation [LOOCV]) of a preexisting SIRSI-5 cut point score (≥59/100) to determine participants who had returned to their preinjury level of sport. In addition, the discrimination ability (LOOCV) of multivariable machine learning models including age, sex, time since injury (months), SIRSI-5 (continuous score), surgery, and contact/noncontact sport to predict return to preinjury level sport was also assessed. The Youden index was calculated to assess the models' performance. Results: Of the 79 participants, 62 (78.5%) were male and 27 (34%) had been treated surgically. Only 32% (n = 25) of participants had returned to preinjury level sport. The SIRSI-5 and SIRSI-12 were highly correlated ( Conclusion: The SIRSI-5 has excellent convergent validity with the SIRSI-12 to measure psychological readiness to RTS and can be used clinically with less patient burden than the SIRSI-12. However, in a population of surgically and nonsurgically treated contact athletes, the SIRSI-5 with a cut point of ≥59/100 had low levels of prediction accuracy for RTS at preinjury level. The SIRSI-5 should not be utilized in isolation to determine readiness to RTS, and clinicians should consider other factors such as age, type of sport, and time since injury to underpin their clinical reasoning when deciding for RTS.