Table 2 Summary of modelling methods and validation

From: Systematic review of prognostic models in Parkinson’s disease

Author/year

Methods to handle missing data

Modelling method

Calibration; discrimination methods

Model performance

Model presentation (sufficient/insufficient for model use in practice)

Almeida 20167

Complete case

Cox regression

Not done; C-statistic

Good discrimination (AUC around 0.8)

Only coefficients (insufficient)

Ashburn 20018

Not stated

Logistic regression

Not done; Not done

Not reported

Only coefficients (insufficient)

Custodio 20169

Not stated

Logistic regression

H-L test; C-statistic

Limited statistical power on calibration; good discrimination (AUC = 0.93)

Only coefficients (insufficient)

Duncan 201510

Complete case

Logistic regression

H-L test & calibration table; C-statistic

Limited statistical power on calibration; good discrimination (AUC = 0.83)

Only coefficients (insufficient)

Ehgoetz Martens 201811

Not stated

Logistic regression

H-L test; Not done

Limited statistical power on calibration

Full equation (sufficient)

Exarchos 201212

Not stated

Decision tree

Not done; not done

Not reported

No information (insufficient)

Gervasoni 201513

Complete case

Logistic regression

Not done; C-statistic

Fair to good discrimination (AUC = 0.72–0.84)

Only coefficients (insufficient)

Gu 202014

Multiple imputation

XGBoost & logistic regression

Calibration plot & H-L test; C-statistic

Good calibration in logistic regression and underpredicted in XGBoost; good discrimination both models (AUC > 0.9)

Full equation (sufficient)

Kelly 201915

Complete case

Cox regression

Not done; C-statistic

Fair discrimination (AUC = 0.68)

Not applicable (external validation study)

Kerr 201016

Not stated

Logistic regression

Not done; C-statistic

Fair discrimination (AUC = 0.74)

No information (insufficient)

Lindholm 201617

Not stated

Logistic regression

H-L test; not done

Limited statistical power for calibration; not reported.

Only coefficients (insufficient)

Liu 201718

Complete case

Frailty Cox model

Not done; C-statistic

Good discrimination in global cognitive impairment and dementia (AUC > 0.8)

Online risk calculator available (sufficient)

Lo 201919

Not stated

Random forest

Not done; C-statistic

Good discrimination in all 6 outcomes (AUC around 0.8)

No information (insufficient)

Macleod 201820

Single imputation

Weibull model

Calibration plot; C-statistic

Good calibration, fair discrimination (AUCs around 0.75)

Full equation (sufficient)

Mak 201421

Not stated

Logistic regression

Not done; Not done

Not reported

Subset equation of full model (insufficient)

Paul 201322

Single imputation

Logistic regression

H-L test & calibration table; C-statistic

Limited power for calibration; good discrimination (AUC around 0.8)

Only coefficients (insufficient)

Phongpreecha 202023

Restricted Boltzmann machine

Generalised multitask

Not done; C-statistic

Unclear discrimination performance (range of C-statistics only)

No information (insufficient)

Pouwels 201324

Not stated

Cox regression

Not done; C-statistic

Fair discrimination (AUC around 0.7)

No information (insufficient)

Redensek 201925

Complete case

Cox regression

Not done; C-statistic

Fair discrimination (AUC around 0.7)

Only coefficients (insufficient)

Schapira 201226

Not stated

Cox regression

Not done; C-statistic

Fair discrimination

Full equation and online risk calculator (sufficient)

Schrag 201727

Single imputation

Logistic regression

H-L test; C-statistic

Limited power for calibration; good discrimination (AUC around 0.8)

Full equation (sufficient)

Velseboer 201628

Multiple imputation

Logistic regression

Calibration plot & slope and H-L test; C-statistic

Good calibration; fair discrimination in internal validation (AUC = 0.75) and good discrimination in external validation (AUC = 0.85)

Full equation (sufficient)

Wang 201729

Complete case

Joint modelling

Not done; C-statistic

Fair discrimination (AUC = 0.75–0.79)

Full equation (sufficient)

Wang 201730

Not stated

Bayesian linear mixed-effects model

Not done; C-statistic

Good discrimination (AUC = 0.99)

Full equation (sufficient)

Ye 201731

Not stated

Cox regression

Not done; C-statistic

Good discrimination (IAUC = 0.79)

Only coefficients (insufficient)

  1. AUC area under the receiver-operator curve, H-L Hosmer-Lemeshow, IAUC incremental Area Under Curve.