Reporting performance of prognostic models in cancer: a review

Table 3 Model performance on data used to develop model and usability* (n = 42)

	Articles with risk groups (n = 36)	Articles with PI but no risk groups (n = 6**)
Presentation of discrimination of model predictions†
KM for risk groups	34	NA
Nomogram	2	4
Other graphical	2	2
% survival probability at fixed time††	22	0
Index of discrimination (see below)	9	2
Log rank	17	NA
Unspecified P-value	6	0
No presentation	0	0
Index of discrimination$
c-index	7	1
R squared or goodness of fit or Brier score	1	1
D	0	0
Other - K (Begg), sensitivity and specificity	2	0
Reclassification of patient risk	0	0
Calibration
Yes	1	1
No	35	5
Model usability from article$$
Prognostic score or risk group can be assigned	33	6
Survival presented for risk group and/or prognostic score	36	5
Instructions for use suitable for physicians included	3	3

* Five articles did not develop PI or use risk groups.
**Four of six articles had some commonality: three articles included the same author, one the same department.
†More than one option possible.
†† All articles have either KM or % survival by risk group.
$ Two articles with risk groups report two indices of discrimination.
$$ Four articles are unusable, lacking one or other criteria.

ISSN: 1741-7015