Decision tree for surgery.

<p>Decision tree for surgery.</p

Performance of risk matrix in derivation and validation cohort for disabling disease and reoperation (% [CI 95%]).

<p>Performance of risk matrix in derivation and validation cohort for disabling disease and reoperation (% [CI 95%]).</p

Decision tree for reoperation.

<p>Decision tree for reoperation.</p

Baseline characteristics and comparison between the derivation and the validation cohorts.

<p>Baseline characteristics and comparison between the derivation and the validation cohorts.</p

Decision rules and proportion and confidence intervals of outcomes observed.

<p>Decision rules and proportion and confidence intervals of outcomes observed.</p