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. 2020 Dec 22;3(12):e2030824. doi: 10.1001/jamanetworkopen.2020.30824

Table 1. Characteristics of the Sample.

Characteristic Participants, No. (%) Test statistic (χ2 or F) P value
TBI (n = 69) Control (n = 70)
Age, mean (SD), y 50.0 (10.3) 49.9 (11.9) 0.001a .97
Women 7 (10.1) 15 (21.4) 3.32b .07
Education level, mean (SD)c 6.7 (1.8) 6.8 (1.8) 0.12a .73
Hypertension 25 (36) 27 (39) 0.08b .78
Diabetes 13 (19) 12 (17) 0.07b .80
Hazardous drinking or alcohol use disorder 26 (38) 22 (31) 0.61b .44
Posttraumatic stress disorder 6 (9) 4 (6) 0.46b .50
TBI severity score, mean (SD) 2.3 (2.7) NA NA NA

Abbreviations: NA, not applicable; TBI, traumatic brain injury.

a

F test was used for numeric variables.

b

χ2 test was used for categorical variables.

c

Education level was coded as follows: 1 = less than 8 years, 2 = some high school, 3 = graduated high school, 4 = general education diploma, 5 = work toward associate’s degree, 6 = completed associate’s degree, 7 = work toward bachelor’s degree, 8 = completed bachelor’s degree or higher, 9 = other.