To investigate the reliability and validity of the Perceive, Recall, Plan and Perform System of Task Analysis (PRPP-Assessment) by parent-provided videos of children with mitochondrial disorders.Methods
Videos of 13 children performing 3–7 activities each were the subject of study, resulting in 65 activities. These were scored using the PRPP-Assessment by 11 raters. Internal consistency was calculated with Cronbach’s alpha. Intra-rater reliability was evaluated by Bland-Altman Plots on 44 PRPP-Assessment scores. Inter-rater reliability was calculated with ICCAgreement on 128 PRPP-Assessment scores. Construct validity was assessed by comparing the PRPP-Assessment scores to the Canadian Occupational Performance Measure using Cohen’s Kappa. PRPP-Assessments scores were evaluated with a multi-faceted Rasch Analysis.Results
Internal consistency was high (0.92). Intra-rater reliability was sufficient to be good (92–96% within the 95%-Limits of the Agreement). The ICCAgreement for stage 1 Mastery Score showed acceptable inter-rater reliability (0.646). Stage 2 of the PRPP-Assessment showed low ICCs due to a lack of variability within the sample. Four out of six hypotheses on validity were accepted. Rasch's analysis demonstrated sound goodness-of-fit, and supported the validity of the PRPP-Assessment.Conclusion
The PRPP-Assessment by parent-provided videos in this heterogenic group showed sufficient to good psychometric properties. In practice, careful task selection and formulating criterion is recommended.