Table 6.

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

Study sites	One shock trauma, one ED in referral centres (Maryland) n=428		Two EDs in university system (Kentucky) n=385		EDs in level I, II, III trauma hospitals (Colorado) n=368*		EDs in all acute care hospitals (Massachusetts) n=388
Level of certainty of TBI	Count	%	Count	%	Count	%	Count	%
Highest‡	232	54.2	219	56.9	286	77.7	259	66.8
Medium	12	2.8	16	4.2	25	6.8	59	15.2
Lowest	47	11.0	41	10.7	21	5.7	40	10.3
Highest + medium levels	244	57.0	235	61.0	311	84.5	318	82.0
All levels of certainty	291	68.0	276	71.7	332	90.2	358	92.3
No TBI documentation	111	25.9	109	28.3	36	9.8	30	7.7

*Skull fracture ICD-10-CM diagnosis codes beginning with ‘S02.0’, ‘S02.1’, ‘S02.8’ or ‘S02.91’ in any diagnosis field and seventh character of ‘A’ ‘B’ or missing. The billing record could not also have an intracranial injury code beginning with ‘S06’.

†The proportion of highest certainty of TBI is statistically significant by study site. Χ²=57.0761, p<0.0001.

‡Seventeen 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 are excluded.

ED, emergency department; ICD-10-CM, International Classification of Diseases, Tenth Revision, Clinical Modification; TBI, traumatic brain injury.