Validation of a UPDRS-/MDS-UPDRS-based definition of functional dependency for Parkinson's disease

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Ramsay, N
Macleod, AD
Alves, G
Camacho, M
Forsgren, L
Lawson, RA
Maple-Grødem, J
Tysnes, OB
Williams-Gray, CH
Yarnall, AJ
Counsell, CE
Rachael A Lawson
Guido Alves, S
Khoo, TK
et al.
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Introduction: Functional dependency in basic activities of daily living (ADLs) is a key outcome in Parkinson's disease (PD). We aimed to define dependency in PD, using the original and MDS versions of the Unified Parkinson's Disease Rating Scale (UPDRS). Methods: We developed two algorithms to define dependency from items of UPDRS Part 2 and MDS-UPDRS Part 2 relating to basic ADLs (feeding, dressing, hygiene and walking, and getting out of a chair). We validated both algorithms using data from 1110 patients from six community-based PD incidence cohorts, testing concurrent validity, convergent validity, and predictive validity. Results: Our optimal algorithm showed high specificity and moderate to high sensitivity versus Schwab & England <80% (specificity 95% [95% confidence interval (CI) 93–97] and sensitivity 65% [95% CI 55–73] at baseline; 88% [95% CI 85–91] and 85% [95% CI 79–97] respectively at five-years follow-up). Convergent validity was demonstrated by strong associations between dependency defined by the algorithm and cognition (MMSE), quality of life (PDQ39), and impairment (UPDRS part 3) (all p < 0.001). Algorithm-defined dependency status also predicted mortality: HR for mortality in those dependent vs independent at baseline was 1.6 (95%CI 1.2–2.1) and in those dependent vs independent at five-years’ follow-up was 2.2 (1.6–3.0). Discussion: We have demonstrated the concurrent validity, convergent validity, and predictive validity of a UPDRS-/MDS-UPDRS-based algorithm to define functional dependency in PD. This can be used for studying dependency in any study where UPDRS or MDS-UPDRS part 2 data have been collected.

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Parkinsonism and Related Disorders

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© 2024. This manuscript version is made available under the CC-BY-NC-ND 4.0 license

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Ramsay, N; Macleod, AD; Alves, G; Camacho, M; Forsgren, L; Lawson, RA; Maple-Grødem, J; Tysnes, OB; Williams-Gray, CH; Yarnall, AJ; Counsell, CE; Rachael A Lawson, ; Guido Alves, S; Khoo, TK, Validation of a UPDRS-/MDS-UPDRS-based definition of functional dependency for Parkinson's disease, Parkinsonism and Related Disorders, 2020, 76, pp. 49-53