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, double dagger 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.