Table 3:

Interobserver agreement and univariate correlation of variables for brain injury (n = 4060)

Characteristic	Brain injury, no. (%) of patients		p value	κ value n = 336^*
Characteristic	Yes n = 197	No n = 3863	p value	κ value n = 336^*
Findings from the CATCH rule
GCS score < 15 at 2 h after injury	20.3	5.2	< 0.001	0.69
Suspected open or depressed skull fracture	25.4	2.5	< 0.001	0.34
Worsening headache, n = 3401^†	11.7	4.8	< 0.001	0.66
Irritability on examination	40.6	7.2	< 0.001	0.61
Signs of basal skull fracture	14.2	1.1	< 0.001	0.77
Large and boggy scalp hematoma	31.5	4.6	< 0.001	0.59
Dangerous mechanism: motor vehicle related, fall from elevation > 3 ft or 5 stairs, fall from bicycle with no helmet	64.5	29.2	< 0.001	NA
Other findings
Witnessed loss of consciousness	31.5	29.6	0.6	0.61
Disorientation or confusion (witnessed)	49.7	51.4	0.7	0.51
Amnesia before impact > 30 min, n = 1677^†	43.8	25.7	< 0.001	0.61
Amnesia after impact > 30 min, n = 1684^†	51.4	34.4	0.003	0.60
Vomiting ≥ 2 episodes	47.2	36.3	0.002	0.99
Vomiting ≥ 3 episodes	43.7	28.4	< 0.001	0.84
Vomiting ≥ 4 episodes	37.1	20.3	< 0.001	0.84
Any headache	54.3	52.3	0.6	0.66
Any scalp hematoma	64.0	30.3	< 0.001	0.58
Lethargy on examination	44.2	12.9	< 0.001	0.61
Initial ED GCS score of 13	13.7	1.7	< 0.001	0.69

Note: CATCH = Canadian Assessment of Tomography for Childhood Head injury, ED = emergency department, GCS = Glasgow Coma Scale, NA = not applicable.
↵* Weighted κ. The interobserver agreement is reported using data from the cases (n = 336) with 2 independent physician assessors.
↵† Data applicable to some patients only.