Minimal clinically important difference (MCID) and minimal detectable change (MDC) of Spinal Cord Ability Ruler (SCAR)

Abstract

Study design: Retrospective cohort study.

Objectives: To find minimal clinically important difference (MCID) and minimal detectable change (MDC) of Spinal Cord Ability Ruler (SCAR) in Thai participants with spinal cord injury (SCI).

Setting: Rehabilitation ward at Maharaj Nakorn Chiang Mai Hospital.

Methods: Data of individuals with SCI who were not diagnosed with central cord syndrome and were admitted for the first time for rehabilitation were analyzed. Upper extremities motor score, self-care and mobility items of Spinal Cord Independence Measure version III were collected and used to calculate SCAR difference between data on date of admission and discharge. MCID and MDC were calculated by distribution-based method and categorized for each subgroup according to SCI characteristics.

Results: From data of 311 individuals, MCID of SCAR is approximately 4 for individual with tetraplegia AIS A, B, C; and individual with AIS D at any level, and 2 for individual with paraplegia AIS A, B, C. MDC of SCAR should be 1 for individual with tetraplegia AIS A, B, C; and individual with AIS D at any level and 0.5 for individual with paraplegia AIS A, B, C.

Conclusion: This study provides MCID and MDC of SCAR in each subgroup. These values could be used as a benchmark for clinicians and researchers to determine whether participant has significant improvement or not after receiving an intervention.