Inter and intra-rater reliability and minimal detectable difference of movement disorder-childhood rating scale

BACKGROUND: Movement Disorder-Childhood Rating Scales (MD-CRS) have been designed in two forms (0-3 and 4-18 years) to accurately evaluate various movement disorders in children. AIM: The aim of this study is to evaluate the MD-CRS reliability when used by clinicians and professionals of rehabilitation after a one-day training on scoring it. DESIGN: This is a measurement-focused study of video-recorded sessions. SETTING: Video session carried out inpatient and outpatient. POPULATION : Children with different types of movement disorders. METHODS: After brief training in scoring MD-CRS, five health professionals (a resident doctor, a child neurologist and three physical therapists) independently scored 40 patient videotapes, of children with movement disorders for inter-rater reliability. In addition, the resident doctor scored 80 videos of 40 patients evaluated twice for intra-rater reliability. Reliability was assessed by Intraclass Correlation Coefficient (ICC) and was calculated separately for the two forms of the scale and for each score (Index I, Index II and Global Index). Standard Error of Measurement (SEM) and Minimal Detectable Difference (MDD) were also calculated. RESULTS: For both forms, inter-rater reliability of Global Index and Index I were good with an ICC ranged between 0.83 and 0.95. Instead, results of Index II were substantially moderate for both forms, with an ICC of 0.53 and 0.57, respectively. Intra-rater reliability for all Indexes in both forms was substantial or almost perfect, with values of ICCs ranging from 0.74 to 0.99. MDD values were between 0.05 and 0.17. CONCLUSIONS : MD-CRS 0-3 and MD-CRS 4-18 remain reliable clinical measurement tools for evaluation of movement disorders in developmental age when used by clinicians and professionals of rehabilitation after a specific short training. CLINICAL REHABILITATION IMPACT: MD-CRS 0-3 and MD-CRS 4-18 appear to be a promising outcome measurement tool in large scale studies with children and adolescents affected by various movement disorders either to verify natural history of the disorder or to plan pharmacological and/or surgical intervention programs.