The Development and Evaluation of a Disease-specific Quality-of-Life Questionnaire for Disorders of the Rotator Cuff: The Western Ontario Rotator Cuff Index

TLDR

The study aimed to develop a valid, reliable quality‑of‑life questionnaire for patients with rotator cuff disease. The authors designed and validated the instrument through item generation, reduction, pretesting, reliability assessment, and construct validation in a specific patient cohort. The resulting 21‑item Western Ontario Rotator Cuff Index demonstrated strong construct validity, excellent 2‑week reliability (ICC 0.96), and greater responsiveness than existing shoulder measures.

Abstract

Objective The purpose of this study was to develop a valid and reliable disease-specific quality-of-life measurement tool for patients with rotator cuff disease. Design Health-related quality-of-life measurement tool development. Methods Methodology for the development and evaluation of the tool included the following: 1) identification of a specific patient population, 2) generation of potential items, 3) item reduction, 4) pretesting the prototype instrument, 5) determination of reliability, and 6) validation. Results The final instrument, the Western Ontario Rotator Cuff Index, ‡ has 21 items representing five domains, each with a Visual Analog Scale–type response option. Construct validation demonstrated that this instrument correlated predictably with other measurement tools (Disabilities of the Arm, Shoulder, and Hand outcome measure; American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form; University of California Los Angeles Shoulder Rating Scale; Constant Score; Rowe; Sickness Impact Profile; Short Form 36; and range of motion; 21 of 21 correlations within 0.19). Reliability was very high at 2 weeks, with an intraclass correlation coefficient of 0.96 and was more responsive (sensitive to change) than the other five shoulder measurement tools, global health instruments, and range of motion. Conclusions This measurement tool can be used as the primary outcome in clinical trials evaluating treatments in this patient population, although its features are equally attractive for monitoring patients' progress in clinical practice.