Table 4

PPV for TBI based on a review of ED records with traumatic intracranial injury ICD-10-CM codes*, by study site

Study sites	One shock trauma, one ED in referral centres (Maryland) n=456		Two EDs in university system (Kentucky) n=385		EDs in level I, II, III trauma hospitals (Colorado) n=376‡		EDs in all acute care hospitals (Massachusetts) n=388
Level of certainty of TBI	Count	%	Count	%	Count	%	Count	%
Highest†	400	87.7	285	74.0	280	74.5	273	70.4
Medium	18	3.9	31	8.1	43	11.4	61	15.7
Lowest	17	3.7	43	11.2	36	9.6	41	10.6
Highest + medium levels	418	91.7	316	82.1	323	85.9	334	86.1
All levels of certainty	435	95.3	359	93.3	359	95.5	375	96.6
No TBI documentation	19	4.2	26	6.8	17	4.5	13	3.4

*Intracranial injury ICD-10-CM codes began with ‘S06’ and ‘A’ in seventh character of the code or missing.
†The proportion of highest certainty of TBI is statistically significant by study site. Χ²=44.8266, p<0.0001.
‡Nine of the 385 sampled medical records in Colorado indicated that the patient was not a state resident, was not discharged home, did not have an injury event or was admitted as an inpatient and is not included in this table.
ED, emergency department; ICD-10-CM, International Classification of Diseases, Tenth Revision, Clinical Modification; TBI, traumatic brain injury.