title: Metric attributes of the unified Parkinson's disease rating scale 3.0 battery: part II, construct and content validity.
abstract: This article is the second of a two-part series concerning the metric properties of the following three Parkinson's disease (PD) scales: modified Hoehn and Yahr staging (H&Y), Schwab and England (S&E), and Unified Parkinson's Disease Rating Scale (UPDRS) 3.0. Part II focuses on construct and content validity. To assess construct validity, a sample of 1,136 PD patients completed the above-mentioned PD scales. Correlation coefficients between measures of disability and dysfunction [S&E, UPDRS Activities of Daily Living (ADL), and UPDRS Motor Examination] were |r| = 0.69-0.77, indicating good convergent validity. Results showed that the S&E (F(5,945) = 193.47; P < 0.0001) and UPDRS subscales discriminated between modified H&Y stages (F(20,2784) = 25.28; P < 0.001). A panel of 12 to 13 international experts rated the relevance of the scales and items. This enabled the scales' content validity index to be calculated, which ranged from 41.7% (UPDRS Mentation) to 83.3% (UPDRS Motor Examination). In conclusion, while the modified H&Y, S&E, and UPDRS displayed satisfactory construct validity, the content validity of all scales except UPDRS Motor Examination failed to attain adequate standards.
authors.affiliation: Neuroepidemiology Unit, National Center for Epidemiology, Carlos III Institute of Health, Madrid, Spain.
authors.forename: Maria João
authors.initials: MJ
authors.lastname: Forjaz
authors.forename: Pablo
authors.initials: P
authors.lastname: Martinez-Martin
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009460:Neurologic Examination; D010300:Parkinson Disease / Q000175:diagnosis*; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D014894:Weights and Measures