Table 2.

Methodological decisions to improve quality in prediction models

Criteria17	Methodological decisions to improve quality
Study design
Inception cohort	Clear description of population. Clear description of the participants at baseline.
Source population	Clear description of population. Clear description of sampling frame and recruitment (method and timing).
Inclusion and exclusion criteria	Clarity of eligibility criteria.
Prospective design	Clarity of study design
Study attrition
No of drop-outs	Adequate participation rate. Clear description of attempts to collect information on participants who dropped out.
Information provided on method of management of missing data	Appropriate methods of imputation of missing data.
Predictive factors
All predictive factors described used to develop the model	Clear definition of predictive factors. An adequate proportion of participants has completed data for the predictive factor.
Standardised or valid measurements	The measurement of the predictive factor is reliable and valid. The measurement of the predictive factor is the same for all participants.
Linearity assumption studied	Linearity of data will be reported.
No dichotomisation of predictive variables	Continuous variables will be reported.
Data presentation all predictive factors	Complete data will be presented.
Outcome measures
Description of outcome measures	The outcome is clearly defined.
Standardised or valid measurements	The measurement of the outcome is reliable and valid. The measurement of the outcome is the same for all participants.
Data presentation of most important outcome measures	Complete data will be presented.
Analysis
Presentation of univariate crude estimates	An appropriate strategy for model building is described. An adequate statistical model described.
Sufficient numbers of subjects per variable	Adequate data will be presented.
Selection method of variables explained	Sufficient data will be presented to enable assessment of the adequacy of the analytic strategy. All results will be reported.
Presentation of multivariate estimates	An appropriate strategy for model building is described. An adequate statistical model described.
Clinical performance/validity
Clinical performance	Clinical performance of the model will be reported.
Internal validation	Internal validation will be reported
External validation	Not a focus of this study