External Validation of the Minimum Clinically Important Difference in the Timed-up-and-go Test After Surgery for Lumbar Degenerative Disc Disease

Abstract

Objective. The aim of this study was to provide external validation of the minimum clinically important difference (MCID) of the Timed-up-and-go (TUG) test. Summary of Background Data. The TUG test is one of the best explored and most frequently applied objective task-based functional outcome measure in patients with lumbar degenerative disc disease (DDD). The increased use of the TUG test is based on its solid psychometric properties; however, an external validation of the originally determined MCID is lacking. Methods. Forty-nine patients with lumbar DDD, scheduled for elective spine surgery, were assessed pre-and 6-weeks (W6) postoperative. MCID values were calculate for raw TUG test times (seconds) and standardized TUG z scores using three different computation methods and the following established patient-reported outcome measures (PROMs) as anchors: Visual Analog Scales (VAS), Core Outcome Measures Index Back, Zurich Claudication Questionnaire (ZCQ).Results. The three computation methods generated a range of MCID values, depending on the PROM used as anchor, from 0.9 s (z score of 0.3) based on the VAS leg pain to 3.0 seconds (z score of 2.7) based on the ZCQ physical function scale. The average MCID of the TUG test across all anchors and computation methods was 2.1 s (z score of 1.5). According to the average MCID of raw TUG test values or TUG z scores, 41% and 43% of patients classified as W6 responders to surgery, respectively. Conclusion. This study confirms the ordinally reported TUG MCID values in patients undergoing surgery for lumbar. A TUG test time change of 2.1 seconds (or TUG z score change of 1.5) indicates an objective and clinically meaningful change in functional status. This report facilitates the interpretation of TUG test results in clinical routine as well as in research.

Effects of a home-based, exergaming intervention on physical function and pain after total knee replacement in older adults: a randomised controlled trial

“…The TUG MCIC has not been validated in patients with TKR. However, at 4 months, the mean change in the IG was similar to the TUG MCIC in lumbar surgery patients37 and thus may also support the observed early satisfaction. Moreover, gamification may affect patients’ expectations and experience of TKR and, thus, overall satisfaction 38…”

Effects of Exercise on Patients Important Outcomes in Older People With Sarcopenia: An Umbrella Review of Meta-Analyses of Randomized Controlled Trials

“…To assess if the effect is important to patients in the study, we used the minimally important difference (MID) of important sarcopenic outcomes. The MID for grip strength, walking speed, and a TUG test time were 5.0 kg (grip strength) (28), 0.10 m/s (walking speed) (29), 2.1 s (TUG test time) (30), respectively.…”

Is telehealth an effective and feasible option for improving falls-related outcomes in community-dwelling adults with neurological conditions? A systematic review and meta-analysis

“…Similarly, five of six comparator interventions were found to lead to statistically significant improvements in balance. Published minimal clinically important difference scores in neurological populations for Berg balance scale are between three 68 and five points, 69 and for timed up and go test, >2.1 s. 70,71 Following six of 10 telehealth interventions, 50,51,55,59,64,67 the magnitude of improvement in Berg balance scale scores may be considered clinically meaningful, compared to three of seven comparator interventions. 50,51,67 For timed up and go test scores, two out of four telehealth interventions 52,67 and one of three comparator interventions 67 led to meaningful improvements (Figures 1A and 1B in the Supplementary File).…”