Minimal clinically important differences (MCID) and patient acceptable symptomatic state (PASS) for visual analog scales (VAS) measuring pain in patients treated for rotator cuff disease
Tashjian, Robert Z.; Deloach, Julia; Porucznik, Christina A.; Powell, Amy P.
Journal of Shoulder & Elbow Surgery
BACKGROUND: The MCID is the smallest difference in an outcome score which a patient perceives as beneficial. The PASS is the score below which patients consider themselves well. The purpose of this study was to determine the MCID and PASS for a visual analog scale (VAS) measuring pain in patients treated for rotator cuff disease. MATERIAL AND METHODS: 81 patients with rotator cuff disease were evaluated after 6 weeks of non-operative treatment with a VAS measuring pain and two transition questions utilized in determining the MCID and PASS. RESULTS: The MCID and PASS were estimated to be 1.4 cm (P = .0255) and 3 cm (95% CI – 22.69, 37.31) on a 10 cm VAS measuring pain, respectively. Age (P = .0492) and hand-dominance (P = .0325) affected the MCID while age (P = .0376) and duration of follow-up (P = .0131) affected the PASS. DISCUSSION: The MCID and PASS estimates provide the basis to determine if statistically significant changes in VAS pain scores after treatment are clinically important and if the treatment allowed patients to achieve a satisfactory state. LEVEL OF EVIDENCE: Level 3; Nonconsecutive series of patients, diagnostic study.