Table 1. .

Sample sizes for population and subgroups in training and test datasets

Sample	Training set (n = 250)		Test set (n = 44)
	Total	Subgroup	Total	Subgroup
Range	17–1305	8–653	8–477	1–185
Mean	126.7	50.0	96.6	38.1
Median	77	29	39	20
Studies with n ≤ 50	80 (32.0%)	192 (76.8%)	23 (52.3%)	35 (79.6%)
Studies with n ≤ 30	24 (9.6%)	136 (54.4%)	14 (31.8%)	28 (63.6)
Studies with n ≤ 20	3 (1.2%)	82 (32.8%)	8 (18.2%)	22 (50.0%)