Table 1 Summary of the characteristics of the validation methods (OTU: Observation Time Uncertainty, TTE: Time-To-Event)

Raw coverage

Based on the reported and non pre-processed data

A graphical check can easily be performed to assess the quality of the coverage

Does not take into account the OTU

Strongly dependent on the width of the predicted interval

Does not rely on a statistical test

Juncture

Takes into consideration the OTU

A graphical check can easily be performed to see how well the observed and predicted intervals overlap

Strongly dependent on the width of both observed and predicted intervals

A minimal overlap between the two intervals is enough to consider the predictions as validated for a given time point

Does not rely on a statistical test

Bootstrapped log-rank (without OTU)

Based on a statistical test frequently used in a TTE context

Combined with a bootstrap approach to avoid an excess of statistical power

Does not take into account the OTU

Credibility of the result if the proportional hazards assumption is not met

Bootstrapped log-rank (with OTU)

Based on a statistical test frequently used in a TTE context

Combined with a bootstrap approach to avoid an excess of statistical power

Takes into consideration the OTU

Credibility of the result if the proportional hazards assumption is not met

Bootstrapped combination of weighted log-ranks (without OTU)

Based on an improved version of the log-rank test, more robust in case of non-proportional hazards

Combined with a bootstrap approach to avoid an excess of statistical power

Does not take into account the OTU

Can be overly sensitive to minor differences because of its design

Bootstrapped combination of weighted log-ranks (with OTU)

Based on an improved version of the log-rank test, more robust in case of non-proportional hazards

Combined with a bootstrap approach to avoid an excess of statistical power

Same as above

Takes into consideration the OTU

Can be overly sensitive to minor differences because of its design