Development and validation of prognostic survival models in newly diagnosed Parkinson’s disease

Angus D Macleod, Ingvild Dalen, Ole-Bjørn Tysnes, Jan Petter Larsen, Carl E Counsell

Research output: Contribution to journalArticle

3 Citations (Scopus)
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Abstract

OBJECTIVE: The objective of this study was to develop valid prognostic models to predict mortality, dependency, and "death or dependency" for use in newly diagnosed Parkinson's disease (PD).

METHODS: The models were developed in the Parkinsonism Incidence in North-East Scotland study (UK, 198 patients) and validated in the ParkWest study (Norway, 192 patients), cohorts that attempted to identify and follow-up all new PD cases in the study area. Dependency was defined using the Schwab & England scale. We selected variables measured at time of diagnosis to include in the models. Internal validation and external validation were performed by calculating C-statistics (discrimination) and plotting observed versus predicted risk in quantiles of predicted risk (calibration).

RESULTS: Older age, male sex, increased severity of axial features, and Charlson comorbidity index were independent prognostic factors in the mortality model. Increasing age, higher smoking history, increased severity of axial features, and lower MMSE score were independent predictors in the models of dependency and "death or dependency." Each model had very good internal calibration and very good or good discrimination (internal and external C-statistics for the models were 0.73-0.75 and 0.68-0.78, respectively). Although each model clearly separated patients into groups according to risk, they tended to overestimate risk in ParkWest. The models were recalibrated to the baseline risk in the ParkWest study and then calibrated well in this cohort.

CONCLUSIONS: We have developed prognostic models for predicting medium-term risk of important clinical outcomes in newly diagnosed PD. These models have validity for use for stratification of randomization, confounder adjustment, and case-mix correction, but they are inadequate for individualized prognostication. © 2017 International Parkinson and Movement Disorder Society.

Original languageEnglish
Pages (from-to)108-116
Number of pages9
JournalMovement Disorders
Volume33
Issue number1
Early online date4 Oct 2017
DOIs
Publication statusPublished - Jan 2018

Fingerprint

Parkinson Disease
Survival
Calibration
Risk Adjustment
Mortality
Parkinsonian Disorders
Scotland
Norway
Random Allocation
England
Comorbidity
Smoking
History
Dependency (Psychology)
Incidence

Keywords

  • Journal Article
  • Parkinson's disease
  • prognosis
  • mortality
  • dependency

Cite this

Development and validation of prognostic survival models in newly diagnosed Parkinson’s disease. / Macleod, Angus D; Dalen, Ingvild; Tysnes, Ole-Bjørn; Larsen, Jan Petter; Counsell, Carl E.

In: Movement Disorders, Vol. 33, No. 1, 01.2018, p. 108-116.

Research output: Contribution to journalArticle

Macleod, Angus D ; Dalen, Ingvild ; Tysnes, Ole-Bjørn ; Larsen, Jan Petter ; Counsell, Carl E. / Development and validation of prognostic survival models in newly diagnosed Parkinson’s disease. In: Movement Disorders. 2018 ; Vol. 33, No. 1. pp. 108-116.
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note = "Acknowledgments We would like to thank study participants, study personnel, and study funders. Funding agencies: The Parkinsonism Incidence in North-East Scotland (PINE) study was supported by Parkinson's UK (Grants G-0502, G-0914, G-1302), the Scottish Chief Scientist Office (CAF 12/05), the British Medical Association (BMA) Doris Hillier award, RS Macdonald Trust, the Bupa Foundation, National Health Service (NHS) Grampian endowments, NHS R&D, and SPRING. The ParkWest study was supported by the Research Council of Norway (Grant 177966), the Western Norway Regional Health Authority (Grants 911218 and 911949), and the Norwegian Parkinson's Disease Association.",
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T1 - Development and validation of prognostic survival models in newly diagnosed Parkinson’s disease

AU - Macleod, Angus D

AU - Dalen, Ingvild

AU - Tysnes, Ole-Bjørn

AU - Larsen, Jan Petter

AU - Counsell, Carl E

N1 - Acknowledgments We would like to thank study participants, study personnel, and study funders. Funding agencies: The Parkinsonism Incidence in North-East Scotland (PINE) study was supported by Parkinson's UK (Grants G-0502, G-0914, G-1302), the Scottish Chief Scientist Office (CAF 12/05), the British Medical Association (BMA) Doris Hillier award, RS Macdonald Trust, the Bupa Foundation, National Health Service (NHS) Grampian endowments, NHS R&D, and SPRING. The ParkWest study was supported by the Research Council of Norway (Grant 177966), the Western Norway Regional Health Authority (Grants 911218 and 911949), and the Norwegian Parkinson's Disease Association.

PY - 2018/1

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N2 - OBJECTIVE: The objective of this study was to develop valid prognostic models to predict mortality, dependency, and "death or dependency" for use in newly diagnosed Parkinson's disease (PD).METHODS: The models were developed in the Parkinsonism Incidence in North-East Scotland study (UK, 198 patients) and validated in the ParkWest study (Norway, 192 patients), cohorts that attempted to identify and follow-up all new PD cases in the study area. Dependency was defined using the Schwab & England scale. We selected variables measured at time of diagnosis to include in the models. Internal validation and external validation were performed by calculating C-statistics (discrimination) and plotting observed versus predicted risk in quantiles of predicted risk (calibration).RESULTS: Older age, male sex, increased severity of axial features, and Charlson comorbidity index were independent prognostic factors in the mortality model. Increasing age, higher smoking history, increased severity of axial features, and lower MMSE score were independent predictors in the models of dependency and "death or dependency." Each model had very good internal calibration and very good or good discrimination (internal and external C-statistics for the models were 0.73-0.75 and 0.68-0.78, respectively). Although each model clearly separated patients into groups according to risk, they tended to overestimate risk in ParkWest. The models were recalibrated to the baseline risk in the ParkWest study and then calibrated well in this cohort.CONCLUSIONS: We have developed prognostic models for predicting medium-term risk of important clinical outcomes in newly diagnosed PD. These models have validity for use for stratification of randomization, confounder adjustment, and case-mix correction, but they are inadequate for individualized prognostication. © 2017 International Parkinson and Movement Disorder Society.

AB - OBJECTIVE: The objective of this study was to develop valid prognostic models to predict mortality, dependency, and "death or dependency" for use in newly diagnosed Parkinson's disease (PD).METHODS: The models were developed in the Parkinsonism Incidence in North-East Scotland study (UK, 198 patients) and validated in the ParkWest study (Norway, 192 patients), cohorts that attempted to identify and follow-up all new PD cases in the study area. Dependency was defined using the Schwab & England scale. We selected variables measured at time of diagnosis to include in the models. Internal validation and external validation were performed by calculating C-statistics (discrimination) and plotting observed versus predicted risk in quantiles of predicted risk (calibration).RESULTS: Older age, male sex, increased severity of axial features, and Charlson comorbidity index were independent prognostic factors in the mortality model. Increasing age, higher smoking history, increased severity of axial features, and lower MMSE score were independent predictors in the models of dependency and "death or dependency." Each model had very good internal calibration and very good or good discrimination (internal and external C-statistics for the models were 0.73-0.75 and 0.68-0.78, respectively). Although each model clearly separated patients into groups according to risk, they tended to overestimate risk in ParkWest. The models were recalibrated to the baseline risk in the ParkWest study and then calibrated well in this cohort.CONCLUSIONS: We have developed prognostic models for predicting medium-term risk of important clinical outcomes in newly diagnosed PD. These models have validity for use for stratification of randomization, confounder adjustment, and case-mix correction, but they are inadequate for individualized prognostication. © 2017 International Parkinson and Movement Disorder Society.

KW - Journal Article

KW - Parkinson's disease

KW - prognosis

KW - mortality

KW - dependency

U2 - 10.1002/mds.27177

DO - 10.1002/mds.27177

M3 - Article

VL - 33

SP - 108

EP - 116

JO - Movement Disorders

JF - Movement Disorders

SN - 0885-3185

IS - 1

ER -