Table 2.

Multivariable regression model of factors associated with TBI visit charges

Variables	Admitted (95%CI)a	P-value	Discharged/Transferred (95%CI)a	P-value
Age (years)
<3	−44.69 (−48.86–(−40.19))	<0.001	−65.35 (−66.76–(−63.87))	<0.001
3–17	−22.51 (−26.42–(−18.39))	<0.001	−44.22 (−45.66–(−42.73))	<0.001
18–44	Referent		Referent
45–59	−4.89 (−6.14–(−3.62))	<0.001	9.29 (8.24–10.35)	<0.001
≥60	−13.35 (−15.34–(−11.30))	<0.001	14.64 (12.33–16.99)	<0.001
Sex (Male)	3.13 (2.36–3.91)	<0.001	7.34 (6.49–8.20)	<0.001
Insurance status
Private	Referent		Referent
Medicare	−10.85 (−13.20–(−8.43))	<0.001	0.42 (−1.30–2.17)	0.632
Medicaid	−5.32 (−8.29–(−2.25))	0.001	−7.03 (−8.79–(−5.23))	<0.001
Self Pay	−5.22 (−8.64–(−1.67))	0.004	5.22 (2.71–7.79)	<0.001
No Charge/Other	0.70 (−3.64–5.23)	0.757	−6.19 (−9.00–(−3.30))	<0.001
Income
0–25th Percentile	Referent		Referent
25–50th	−1.36 (−5.51–2.98)	0.533	−2.72 (−6.19–0.89)	0.138
51–75th	1.57 (−4.39–7.90)	0.614	−4.65 (−8.50–(−0.63))	0.024
76–100th	−0.70 (−15.74–17.03)	0.933	−11.87 (−19.62–(−3.38))	0.007
[Other (Zip blank or miss]	−13.05 (−19.58–(−6.00))	<0.001	2.21 (−2.83–7.51)	0.396
Region
Northeast	Referent		Referent
Midwest	−2.51 (−13.34–9.68)	0.673	5.69 (−2.09–14.09)	0.156
South	8.09 (−12.30–33.24)	0.466	9.44 (−5.38–26.58)	0.224
West	72.28 (51.26–96.21)	<0.001	9.90 (0.89–19.71)	0.031
Injury Severity Score
ISS ≤ 8	Referent		Referent
ISS 9–15	35.25 (28.98–41.82)	<0.001	87.98 (84.44–91.58)	<0.001
ISS ≥ 16	71.63 (60.74–83.26)	<0.001	105.62 (99.97–111.43)	<0.001
Elixhauser Score	2.05 (1.88–2.22)	<0.001	1.94 (1.71–2.17)	<0.001
Length of Stay (continuous days)	5.75 (5.39–6.11)	<0.001	—	—
Year (continuous)	3.85 (1.97–5.76)	<0.001	8.23 (6.99–9.48)	<0.001
Trauma Center	46.17 (33.20–60.40)	<0.001	21.14 (11.45–31.66)	<0.001
Teaching Hospital	−3.70 (−16.57–11.16)	0.61	6.10 (−3.55–16.72)	0.22
Pediatric Hospital	−35.71 (−52.71–(−12.59))	<0.001	−32.38 (−42.14–(−20.96))	<0.001
Metropolitan Area	71.42 (57.06–87.09)	<0.001	23.99 (16.08–32.43)	<0.001
Hospital ownership
Private, non-profit	Referent		Referent
Private, investor-owned	51.47 (35.20–69.69)	<0.001	69.25 (50.85–89.89)	<0.001
Private, not specified	21.23 (3.21–42.40)	0.019	21.93 (7.68–38.06)	0.002
Government, nonfederal	−2.61 (−14.26–10.61)	0.683	3.92 (−6.15–15.06)	0.460
Government or private	11.53 (−4.28–29.95)	0.162	3.74 (−9.87–19.39)	0.609

^aLog transformed outcome. Associations are presented as percent change compared to reference group. Raw n for “Admitted” model=322,812, weighted n=1,534,983. Raw n for “Discharged/Transferred” model=2,066,630, weighted n=9,353,464. Abbreviations: TBI= traumatic brain injury.