. Author manuscript; available in PMC: 2016 Aug 4.

Published in final edited form as: Methods Inf Med. 2015 May 29;54(4):328–337. doi: 10.3414/ME14-01-0093

Table 2.

Linkage status by match variable, validation linkage

	Linked^a N = 218	Unlinked^a N = 28	overall P	test (if not exact)
Administrative variables
Demographics
Age, years (median(IQR))	6 (3–12)	5 (1.5–10.5)	0.22	ranksum
Admission year, mode (%)	2008 (33)	2008 (36)	0.34
Discharge year, mode (%)	2008 (30)	2008 (36) b	0.22
Male, n (%)	131(60)	20(71)	0.31
Insurance type, mode (%)	“other”, (43)	“insurance”, (50)	0.11
Race/ethnicity, mode (%)	“white”, (61)	“white”, (71)	0.24
Missing, n (%)	52(24)	6(21)
Hospital Course
ICU admission, n (%)	217 (100)	27 (96)	0.22
ICU days, median (IQR)	3 (1–8)	1 (1–2)	< 0.001	ranksum
Missing, n (%)	1 (0)	1 (4)
Hospital LOS, days(median (IQR))	9 (4–17)	4 (2.5–5)	< 0.001	ranksum
Discharge disposition, mode (%)	“home”, (66)	“home”, (93)	0.04
ICD-9-CM variables
Injury Severity
Injury Mechanism, mode (%)	“MVT”, (38)	“other” (39)	0.04
Injury Severity Score (ISS)	17 (10–27)	9 (9–16)	< 0.001	ranksum
Body region AIS scores
Head, mode (%)	3 (39)	3 (43)	0.31
Number Non-Head AIS ≠ 0, median (IQR)	1 (0–2)	0 (0–1)	< 0.001	ranksum
Procedures^c
Total count, median (IQR)	1 (0–2)	1 (0–1)	0.06	ranksum