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

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.

Keywords: Minimal clinical important difference (MCID), patient acceptable symptomatic state (PASS), outcome, visual analogue scale (VAS), pain, rotator cuff