Characteristics of included studies*
| First author (year)ref | Country (Study duration) | Age range (years) | Male, n (%) | Injury type | Injury severity |
| Albrecht (2018)24 | USA (NR) | ≥18 | 783 (72.2) | Isolated TBI | n (%): AIS 3=262 (24), AIS 4=466 (43), AIS ≥5=356 (33) |
| Bakke (2016)25 | Norway (1 year) | ≥18 | 618 (62.0) | Mixed injuries | NR |
| Banks (2019)26 | USA (1 January 2012–21 December 2016) | ≥16 | 16 035 (75.4) | Mixed injuries | Median ISS (IQR)=5 (2–11) |
| Benson (2018)27 | USA (2007–2012) | ≥18 | 22 891 (80.7) | Mixed injuries requiring laparotomy | Mean ISS (SD)=20.2 (15) |
| Bernier (2016)28 | USA (January 1992–December 2009) | ≥18 | 8389 (70.2) | Moderate to severe TBI | NR |
| Bjarkø (2019)29 | Norway (1 October 2004–30 September 2014) | ≥16 | 365 (74) | Moderate to severe TBI | Median GCS score (IQR)=8 (4–12) |
| Bogstrand (2011)30 | Norway (December 2007–December 2008) | ≥18 | 762 (59.9) | Mixed injuries | NR |
| Chippendale (2017)31 | USA (November 2013–May 2015) | >55 | 299 (42.1)† | Mixed injuries | NR |
| Chuang (2016)32 | Taiwan (January 1 2009–December 31 2013) | NR | 1194 (45.4) | n(%): head/neck=585 (22), face=166 (6), thorax=194 (7), abdomen=147 (6), extremity=2009 (76) | Median ISS (range): obese=9 (1–45), normal=9 (1–50) |
| Cordovilla-Guardia (2017)33 | Spain (32 non-consecutive months between November 2011 and March 2015) | 16–70 | 194 (80.2) | Mixed injuries | Median ISS (IQR)=19 (14–26) |
| Cordovilla-Guardia (2018)34 | Spain (31 non-consecutive months between November 2011 and June 2015) | 16–70 | 612 (65.88) | Mixed injuries | n (%): Mild (ISS 1–8)=698 (75.1), moderate (ISS 9–15)=161 (17.3), severe (ISS ≥16)=70 (7.5) |
| Dorji (2017)35 | Bhutan (April 8 2015–October 21 2015) | NR | NR | Mixed injuries | n (%): No apparent injury=36 (11), minor or superficial=144 (43), moderate=147 (43), severe=8 (2) |
| Ekeh (2014)36 | USA (January 2006–December 2010) | ≥65 | 728 (55.9)* | Mixed injuries | Mean ISS (SD): Substance use=12.8 (8.8), no substance use=14.3 (9.2) |
| Forson (2016)37 | Ghana (November 3 2014–April 11 2015) | ≥18 | 756 (70) | Mixed injuries | n (%) maximum AIS≥3=311 (28.7) |
| Martin et al (2017)39 | USA (September 2013–March 2015) | >17 | 6810 (66.8) | Blunt trauma | Mean ISS (SD)=11 (10) |
| McAllister (2013)40 | UK (January 2011–January 2012) | >16 | NR | Maxillofacial injuries | NR |
| McLaughlin (2017)41 | USA (March 2012–May 2014) | ≥18 | 233 (61.5) | Mixed injuries | Mean ISS (SD)=12.1 (8.3) |
| Nguyen (2014)42 | USA (January 1 2010–December 31 2012) | ≥15 | 349 (78.3) | TBI | Mean ISS (SD)=20.8 (10.9) |
| Nweze (2016)43 | USA (January 2013–December 2013) | 15–70 | 527 (71.4) | Mixed injuries | Mean ISS (SD)=7.37 (7.01) |
| Pandit (2014)44 | USA (2007–2010) | ≥18 | 16 045 (66.9) | Isolated severe blunt TBI | AIS≥4 |
| Peng (2016)45 | Taiwan (January 1 2009–December 31 2014) | 20–65 | 6934 (62.8) | Mixed injuries | Median ISS (IQR): Intoxicated=10 (5.17), not intoxicated=5 (4.9) |
| Rundhaug (2015)46 | Norway (October 2004–October 2011) | 16–70 | 206 (77.7) | Moderate to severe TBI | Median ISS (IQR): BAC measured=25 (17-32), BAC not measured=25 (17-29) |
| Staton (2018)47 | Tanzania (August 5 2013–July 21 2014) | ≥18 | 394 (76.4) | n(%): Fracture=185 (35.8), Dislocation=80 (15.5), Open wound=197 (38.2), Bruise=111 (22.5), Concussion=149 (28.9), Organ injury=56 (10.9) | Mean Kampala Trauma Score (SD)=14.3 (0.9) |
| Strong (2016)48 | USA (January 1997–December 2008) | ≥18 | 4980 (66.8) | Hip fractures=578 (7.7) | n(%): ISS 1–8=3,849 (51.0), ISS 9–15=1,651 (21.9), ISS 16–24=1,050 (13.9), ISS 25–49=663 (8.8), ISS ≥50=32 (0.4), ISS missing=296 (3.9) |
| Talving (2010)49 | USA (2003) | 18–64 | 692 (84.9) | Severe isolated TBI | Mean ISS (SD): 7.5 (6.8) |
| Valdez (2016)50 | USA (1 January 2012–31 December 2012) | ≥18 | 977 (70.0) | Mixed injuries | Mean ISS (SD)=7.5 (6.8) |
| Ye (2013)53 | Canada (1989–2009) | NR | NR | NR | NR |
| USA (1985–1996) | |||||
| Brazil (2001) | |||||
| Argentina (2001) | |||||
| Dominican Republic (2010–2011) | |||||
| Guatemala (2010–2011) | |||||
| Guyana (2010–2011) | |||||
| Mexico (1986–2002) | |||||
| Nicaragua (2010–2011) | |||||
| Panama (2010–2011) | |||||
| Yue (2017)51 | USA (2010–2012) | ≥18 | 72 (67.3) | Blunt, uncomplicated mild TBI | n (%): GCS 13=5 (4.7), GCS 14=33 (30.8), GCS 15=69 (64.5) |
| Yue (2020)52 | USA (2010–2012) | ≥16 | NR (68.4) | TBI | n (%): GCS<15=71 (53.4), GCS 15=60 (45.1) |
*See online supplemental appendix C for additional study characteristics including socioeconomic status, non-acute AOD use, injury type and injury severity.
†Some values were estimated using available data.
AIS, Abbreviated Injury Scale; BAC, blood alcohol concentration; GCS, Glasgow Coma Scale; ISS, Injury Severity Score; NR, not reported; TBI, traumatic brain injury.