Table 3.

Correlation between monthly trauma volume and other survey variables.

Cut-off value of trauma volume (person/month)	Low volume		High volume
	Number of months	Positive rate of HCTs	Number of months	Positive rate of HCTs	Overall performance
	n	mean (SD)	n	mean (SD)	P value∗	AUC	P value
1100	0	—	20	29.13 (3.44)	—	—	—
1150	1	29.1	19	29.13 (3.53)	0.994	0.421	0.795
1200	3	32.4 (3.3)	17	28.55 (3.21)	0.072	0.804	0.101
1250	7	29.83 (3.49)	13	28.74 (3.49)	0.517	0.549	0.721
1300	13	30.12 (3.09)	7	27.27 (3.49)	0.076	0.703	0.143
1350	14	30.15 (2.97)	6	26.73 (3.49)	0.038	0.762	0.070
1400	18	30.02 (2.79)	2	24.03 (2.03)	0.002	0.972	0.032
1450	19	29.34 (3.39)	1	25	0.228	0.895	0.193
1500	20	29.13 (3.44)	0	—	—	—	—

HCT: head computed tomography.

^∗Correlation is significant at the 0.05 level (2-tailed).