Table 2.

Univariate Effect of Clinical Presentation of Traumatic Brain Injury on the Rate of Hydrocephalus

Characteristic	N	Hydrocephalus, n (%)	P Value
Total (N)	1,244,087	930 (0.07)
Clinical presentation (loss of consciousness)			<0.0001
None	674,148	380 (0.06)
Brief (<1 hour)	171,957	107 (0.06)
Moderate (1–24 hours)	1773	<11
Prolonged (≥24 hours), baseline return	673	23 (3.42)
Prolonged (≥24+ hours), no baseline return	3649	81 (2.23)
Other	391,888	334 (0.09)
Type of traumatic brain injury			<0.0001
Concussion	1,157,346	325 (0.03)
Laceration/contusion	17,517	55 (0.31)
Subarachnoid hemorrhage	11,875	121 (1.02)
Subdural hemorrhage	17,566	279 (1.59)
Extradural hemorrhage	3360	28 (0.83)
Other	36,423	123 (0.34)
Nature of injury			<0.0001
Open	2222	34 (1.54)
Closed	1,241,866	896 (0.07)
Cause of injury			<0.0001
Motor vehicle accident	126,742	156 (0.12)
Fall	377,556	253 (0.07)
Blunt trauma by person/object	385,234	121 (0.03)
Firearm	1022	23 (2.28)
Cycling incident	32,327	17 (0.05)
Shaken baby syndrome	128	14 (10.94)