Table 4.
Polytomous discrimination index, pairwise c-statistics, and Brier score on the updating data after correction for optimism using bootstrapping
| Updating method | PDI | c-statistic FPUL-IUP | c-statistic FPUL-EP | c-statistic IUP-EP | Brier |
|---|---|---|---|---|---|
| Temporal updating (SGH) | |||||
| No updating | 0.87 (0.85–0.90) | 0.99 (0.98–0.99) | 0.92 (0.89–0.94) | 0.89 (0.85–0.93) | 0.172 (0.155–0.190) |
| Intercept recalibration | 0.87 (0.84–0.89) | 0.99 (0.98–0.99) | 0.92 (0.89–0.94) | 0.89 (0.85–0.92) | 0.165 (0.148–0.183) |
| Logistic recalibration | 0.88 (0.85–0.90) | 0.99 (0.98–>0.99) | 0.93 (0.91–0.95) | 0.91 (0.88–0.94) | 0.158 (0.143–0.173) |
| Refitting | 0.88 (0.85–0.90) | 0.99 (0.99–>0.99) | 0.93 (0.91–0.95) | 0.91 (0.88–0.94) | 0.157 (0.141–0.172) |
| Penalized refitting | 0.88 (0.85–0.90) | 0.99 (0.98–>0.99) | 0.93 (0.91–0.95) | 0.91 (0.88–0.94) | 0.158 (0.142–0.172) |
| Refitting + rcs | 0.88 (0.86–0.91) | 0.99 (0.98–>0.99) | 0.93 (0.91–0.95) | 0.92 (0.89–0.95) | 0.153 (0.137–0.168) |
| Extension | 0.89 (0.87–0.92) | 0.99 (0.99–>0.99) | 0.93 (0.92–0.95) | 0.93 (0.90–0.95) | 0.150 (0.135–0.165) |
| Penalized extension | 0.89 (0.87–0.92) | 0.99 (0.99–>0.99) | 0.93 (0.92–0.95) | 0.93 (0.90–0.95) | 0.150 (0.135–0.165) |
| Geographical updating (QCCH) | |||||
| No updating | 0.80 (0.77–0.83) | 0.95 (0.93–0.97) | 0.91 (0.88–0.94) | 0.84 (0.79–0.88) | 0.286 (0.258–0.314) |
| Intercept recalibration | 0.80 (0.77–0.83) | 0.95 (0.93–0.97) | 0.91 (0.88–0.94) | 0.84 (0.79–0.88) | 0.278 (0.247–0.310) |
| Logistic recalibration | 0.80 (0.77–0.83) | 0.96 (0.94–0.97) | 0.93 (0.90–0.95) | 0.84 (0.79–0.88) | 0.267 (0.243–0.291) |
| Refitting | 0.80 (0.77–0.83) | 0.96 (0.94–0.97) | 0.94 (0.92–0.96) | 0.84 (0.80–0.88) | 0.266 (0.243–0.291) |
| Penalized refitting | 0.80 (0.77–0.83) | 0.96 (0.94–0.97) | 0.94 (0.91–0.95) | 0.84 (0.79–0.88) | 0.265 (0.242–0.289) |
| Refitting + rcs | 0.82 (0.79–0.85) | 0.96 (0.94–0.97) | 0.94 (0.92–0.96) | 0.85 (0.81–0.89) | 0.261 (0.237–0.284) |
| Extension | 0.81 (0.78–0.84) | 0.96 (0.94–0.97) | 0.94 (0.92–0.96) | 0.84 (0.80–0.88) | 0.262 (0.238–0.287) |
| Penalized extension | 0.81 (0.78–0.84) | 0.96 (0.94–0.97) | 0.94 (0.92–0.96) | 0.84 (0.80–0.88) | 0.263 (0.239–0.287) |
PDI polytomous discrimination index, FPUL failed pregnancy of unknown location, IUP intra-uterine pregnancy, EP ectopic pregnancy, SGH St. George’s Hospital, QCCH Queen Charlotte’s and Chelsea Hospital, rcs restricted cubic splines