It Is as It Was: MDS‐UPDRS Part III Scores Cannot Be Combined with Other Parts to Give a Valid Sum

Goetz, Christopher G.; Choi, Dongrak; Guo, Yuanyuan; Stebbins, Glenn T.; Mestre, Tiago; Luo, Sheng

doi:10.1002/mds.29279

Cited by 10 publications

(10 citation statements)

References 17 publications

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“…Moreover, even with the very large data set of this study, the failure of the basic summing strategy for other combinations of MDS-UPDRS Parts (eg, Parts 1 + 2 + 3, Parts 2 + 3 + 4, and Parts 1 + 2 + 3 + 4) should convince the field that such outcomes cannot be utilized in a valid manner in research or clinical practice. 32 This study builds on our previous work that identified the two-domain factor structure, tremor and nontremor, of Part 3 items of MDS-UPDRS. 5 The current study confirmed the stable structure clinimetrically sound regardless of the data collection method.…”

Section: Discussionmentioning

confidence: 95%

“…Our two‐domain solution was a clear best fit for handing the full item bank of Parts 2 + 3, and this finding was not only confirmed by our analysis but also amplified by the failure of both the unidimensional and the three‐dimensional solutions. Moreover, even with the very large data set of this study, the failure of the basic summing strategy for other combinations of MDS‐UPDRS Parts (eg, Parts 1 + 2 + 3, Parts 2 + 3 + 4, and Parts 1 + 2 + 3 + 4) should convince the field that such outcomes cannot be utilized in a valid manner in research or clinical practice 32 …”

Section: Discussionmentioning

confidence: 99%

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Using Movement Disorder Society Unified Parkinson's Disease Rating Scale Parts 2 and 3 Simultaneously: Combining the Patient Voice with Clinician Ratings

et al. 2023

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A BS TRACT: Background: Regulatory recommendations favor outcomes combining objective and patient input. The Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS), the most commonly used scale in Parkinson's disease (PD), includes patient and investigator ratings in distinct parts, but original clinimetric analyses failed to confirm the validity of combining parts by simple summing. Objectives: The aim was to develop clinimetrically valid constructs for combining patient-reported Part 2 and investigator-rated Part 3 MDS-UPDRS scores. Methods: Using 7888 MDS-UPDRS scores, we assessed construct validity of combined Part 2 and Part 3 items using exploratory factor analysis (EFA) and graded item response theory (IRT) with threshold criteria: comparative fit index ≥0.9 (EFA) and discrimination parameters ≥0.65 (IRT). Results: The direct sum of Parts 2 + 3 failed to meet the threshold for a valid outcome of PD severity (comparative fit index, CFI = 0.855). However, a two-domain construct combining item scores for tremor and non-tremor domains from Parts 2 and 3 confirmed validity, meeting both EFA and IRT criteria as distinct but correlated indices of disease severity (CFI = 0.923; discrimination mean 2.197 AE 0.480 [tremor] and 1.737 AE 0.344 [non-tremor] domains). Conclusions: The sum of Parts 2 + 3 is not clinimetrically sound. However, considering tremor and non-tremor items of both Parts 2 and 3 as two outcomes results in a valid summary of PD motor severity that leverages simultaneous patient-and investigator-derived measures. This analytic application addresses regulatory prioritizations and retains the well-validated MDS-UPDRS items. In future interventional trials, we suggest that tremor and non-tremor components of PD motor severity from Parts 2 + 3 be monitored and analyzed to accurately detect objective changes that integrate the patient's voice.

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Section: Discussionmentioning

confidence: 95%

Section: Discussionmentioning

confidence: 99%

Using Movement Disorder Society Unified Parkinson's Disease Rating Scale Parts 2 and 3 Simultaneously: Combining the Patient Voice with Clinician Ratings

et al. 2023

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“…2 Accordingly, in PD, it may reflect the inflammation accompanying neurodegeneration or other pathogenic factors acting within the olfactory system or at a more general level. 3,4 The higher expression in patients with constipation and severe gastrointestinal troubles suggests that the PD-associated bowel inflammation 5 might promote SP expression locally, 6 systemically, or within the vagus nerve pathway in particular, accounting for the overexpression in the olfactory structures that indeed are functionally and anatomically connected. 1,7 Then, the absence of case-control difference in NK1R levels probably underlines the role of SP as an inducible mediator and also excludes an increased expression to compensate for the loss of receptors.…”

Section: Olfactory Neuron Substance P Is Overexpressed In Parkinson's...mentioning

confidence: 99%

“…2 Using a large, independently collected database of MDS-UPDRS ratings, 3 we previously reconsidered the original recommendations and focused on Part 3 (Motor Examination), attempting to sum Part 3 scores with any of the patient-derived Parts (1 and 2). 4 However, this summing strategy failed for Part 3, 5 although more complex item response theory (IRT) modeling can provide a combined Part 2/3 index of tremor and non-tremor severities. 6 In this report, we investigate whether the patient-derived MDS-UPDRS Parts assessing non-motor (Part 1) and motor (Part 2) functional impact of PD can be summed to render a summary score for motor and non-motor experiences of PD from a patient perspective.…”

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confidence: 99%

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Summing MDS‐UPDRS Parts 1 + 2 (Non‐motor and Motor Experience of Daily Living): The Patient's Voice

et al. 2023

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Outcome Selection for Research Studies in Movement Disorders

Fox

2024

Movement Disord Clin Pract

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Choosing the correct outcome measure for any clinical research study in the field of movement disorders depends on the disease being studied and the research question being asked.The clinical features of the movement disorder will impact which outcome measure; when it will be measured and how it will be measured. For example, clinical studies investigating Parkinson's disease (PD) requires knowledge of the myriad of motor and non-motor features of the disease, not only in choosing the correct scale but also the potential impact of other disease features on the proposed outcome measures. The heterogeneity of PD will also affect the type of outcome measure if focussed on one component of the disease for example, tremor versus non-tremor dominant. Outcomes used in dystonia need to be tailored to the body distribution of dystonia such as focal or generalized, as well as other components such as pain and tremor. Some movement disorders are progressive and worsen over time, such that the outcome measure used will impact the trial design. Thus, in early untreated PD, studies using a motor score (eg, MDS-UPDRS III) as a surrogate for "disease progression" when investigating a potential neuroprotective agent, could require a trial to last months to years as the change in MDS-UPDRS III in the early stages of disease is small and non-linear (eg, 3-4 points/year). 1 While later in the disease, the same outcome, MDS UPDRS III, is a measure of symptomatic effects of an intervention and a shorter duration of trial is sufficient. Likewise the effect of symptomatic medications needs to be incorporated into any study investigating potential disease-modification in PD when the MDS-UPDRS is used as an outcome measure. Other challenges to take into consideration include knowledge of the natural history of the movement disorder such as fluctuations in symptoms. This may occur with disorders such as Tics and Tourette's syndrome, and truly paroxysmal movement disorders that may impact the timing and type of outcome measure used. Likewise, fluctuations or changes in symptoms due to symptomatic therapy in PD with motor and non-motor fluctuations is also a major variable to consider when choosing an outcome measure. The natural history of other symptoms in PD may also fluctuate, including psychosis, dyskinesia and many non motor issues that may impact type and timing of outcome measures. 2 Thus knowledge of the seminology is key to designing and incorporating the correct outcome measures.

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It Is as It Was: MDS‐UPDRS Part III Scores Cannot Be Combined with Other Parts to Give a Valid Sum

Cited by 10 publications

References 17 publications

Using Movement Disorder Society Unified Parkinson's Disease Rating Scale Parts 2 and 3 Simultaneously: Combining the Patient Voice with Clinician Ratings

Using Movement Disorder Society Unified Parkinson's Disease Rating Scale Parts 2 and 3 Simultaneously: Combining the Patient Voice with Clinician Ratings

Summing MDS‐UPDRS Parts 1 + 2 (Non‐motor and Motor Experience of Daily Living): The Patient's Voice

Outcome Selection for Research Studies in Movement Disorders

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