Validation of the Stanmore percentage of normal shoulder assessment

Abstract

Background and Purpose: The Stanmore Percentage of Normal Shoulder Assessment (SPONSA) is a patient-reported outcome measure (PROM). The score assesses pain, range of movement, strength, stability and function of the shoulder. The aim of this work was to formally validate the SPONSA. Materials and Methods: Validation of this score was carried out by measuring reproducibility, construct validity and sensitivity to change. Time to completion was also recorded. The Oxford Shoulder Score (OSS) and Constant Score (CS) were used for comparison. These assessments were performed with 61 individuals undergoing shoulder interventions. Results: There was excellent preoperative reproducibility in both intra- and inter-observer groups. The SPONSA had a 0.79 correlation with the OSS and 0.78 with the CS. The overall effect size of the SPONSA was 0.72, which was comparable to OSS (0.65) and greater than CS (0.34), implying equal or better sensitivity to change. Conclusions: The SPONSA is practical and quick to perform and also a reproducible and a sensitive instrument. This simple PROM is a commendable addition to the existing validated scoring methods for the shoulder. Level of Evidence: I; testing of previously developed diagnostic criteria on consecutive patients (with universally applied reference "gold" standard).