Validation of the Visual Analogue Scale in the Cervical Spine

• Objective: The Visual analogue scale (VAS) is frequently used to measure treatment outcome in patients with cervical spine disorders. The minimum clinically important difference (MCID) is the smallest change in a score that has clinical importance to the patient. Although it has been established for other medical fields, knowledge of the VAS MCID for the cervical spine is sparse, and it has rarely been considered in relation to measurement noise. The goals in this study were as follows: 1) to validate the VAS-neck and VAS-arm instruments for the cervical spine (e.g. repeatability); 2) to investigate the possible influence of predictive factors and the Hospital Anxiety and Depression Scale (HADS) score on repeatability; and 3) to compute the MCID with five different methods.Methods: A post hoc analysis of a prospective randomized controlled trial with 151 patients undergoing surgery for cervical radiculopathy due to degenerative disc disease (DDD) was performed. Information on age, sex, smoking habits, exercise and employment status, HADS score, and VAS-neck and VAS-arm scores was gathered before surgery and after 1 year. The VAS was applied twice on every occasion with 15 minutes in-between. Repeatability and the association with predictors and HADS score were analyzed using the one-sample t-test, linear regression models and Spearman correlation. The MCID was calculated with the following methods: average change, change difference, receiver operating characteristic curve, effect size, and minimum detectable change (MDC).Results: The repeatability in VAS-neck was 8.1 mm and in VAS-arm 10.4 mm. Less consistent values on the VAS correlated to female sex and higher values on HADS. For VAS-neck the MCID ranged from 4.6 to 21.4 and for VAS-arm it ranged from 1.1 to 29.1. The highest MCID came from the MDC method, which was the only method that gave values above the measurement noise in both VAS-neck and VAS-arm.Conclusions: Measurement noise in VAS-neck and VAS-arm for the cervical spine was influenced by female sex and HADS score. The only method to compute MCID that consistently gave results above the measurement noise in VAS-neck and VAS-arm was the MDC. 

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Ortopedi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Orthopaedics (hsv//eng)

Nyckelord

Visual analogue scale

Minimum clinically important difference

Cervical degenerative disc disease

Surgical treatment

Hospital anxiety and depression scale.

Orthopaedics

Ortopedi

Publikations- och innehållstyp

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