Table 3.
Results of the random-effects meta-analysis: pooled c-statistic ranging from largest to smallest validation cohort
| Risk score characteristics | Development | Validation | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Original sample size | N of events | Original c-statistic | Model type | Time frame |
N of studiesb (N of validations) |
Sample size | N of events | Pooled c-statistic | |
| CHA2DS2-VASc | 1084 | 25 | 0.61 | Risk score | 1 year | 82 (n = 135) | 3 229 267 | 169 199 | 0.644 (0.635–0.653) |
| CHADS2 | 1733 | 94 | 0.82 | Risk score | 1 year | 46 (n = 68) | 1 479 228 | 71 644 | 0.658 (0.644–0.672) |
| ATRIA | 10 927 | 685 | 0.73 | Risk score | 1 year | 11 (n = 24) | 562 443 | 45 444 | 0.683 (0.658–0.708) |
| AFI | 5955 | 208 | — | Risk score | 1 year | 7 (n = 12) | 153 530 | 6879 | 0.598 (0.558–0.636) |
| GARFIELD-AF | 38 935 | 511 | 0.69 | Formula | 1 year | 4 (n = 13) | 149 848 | 5427 | 0.707 (0.676–0.737) |
| SPAF | 2012 | 130 | — | Risk score | 1 year | 5 (n = 5) | 116 864 | 3778 | 0.650 (0.564–0.726) |
| Modified-CHADS2 | 51 807 | 5526 | 0.72 | Risk score | 5 years | 5 (n = 10) | 109 313 | 10 083 | 0.715 (0.674–0.754) |
| Framingham | 705 | 83 | 0.66 | Risk score | 5 years | 6 (n = 8) | 95 145 | 2716 | 0.633 (0.602–0.662) |
| The ABC stroke risk score | 27 929 a | 391 | 0.68 | Risk score | 1 year | 5 (n = 11) | 40 340 | 1441 | 0.678 (0.658–0.697) |
| GARFIELD-AF II | 52 032 | 957 | 0.68 | Formula | NA | 1 (n = 2) | NA | NA | 0.690 (0.672–0.707) |
NA, data not available. Note that the number of validations slightly differs with Figure 3 since some validations needed to be excluded from the random effect meta-analysis due to studies omitting confidence intervals.
a
Person years.
b
Validation studies were included if discrimination measures (c-statistic) together with confidence intervals were available.