Page 128 - 2020 JSOM Winter

TABLE 2 Anatomic Distribution of Frostbite Injuries in Various Studies
Frostbite
Feet/Toes Hands/Finger Head/Face
Study Sample Cases (n) (%) (%) (%) Other
SMs treated in 48th Surgical Hospital (8th Army)
Vester and Ekman (1953) 281 62 29 9 0
28
in Korea, Winter 1950–1951
Sumner et al (1974) US Soldiers at Fort Wainwright, AK 1967–1970 292 28 25 41 7
26
Rosen et al (1991) Norwegian Soldiers, 1986–1989 40 57 37 6 0
29
Ervasti et al (1991) Reindeer herders in Finland (1-year incidence) 453 6 17 73 4
36
Valnicek et al * (1993) Hospital admissions in central Canada, 1969–1979 125 48 41 4 7
30
31
Lehmuskallio et al (1995) Finnish Conscripts, 1976–1989 2,054 NR NR 45 NR
Himalayan mountaineers treated in Pakistan
Hashmi et al (1998) 1,500 64 32 3 1
32
hospitals, 1985–1994
Cattermole (1998) British Antarctic Survey Personnel, 1986–1995 61 27 21 47 3
37
Juopperi et al (2002) Hospital admissions in Finland, 1986–1995 1,212 61 34 5 0
33
Ervasti et al (2004) Finnish conscripts (lifetime occurrence) 2,555 22 32 46 0
38
Mountaineers in Tehran, Iran (frostbite in last
39
Harirchi et al (2005) 469 24 18 49* 0
2 years)
Gallea et al (2014) Competitors in Iditarod Sled Dog Race, AK, 2010 20 45 35 20 0
34
Heil et al (2016) British Army, 2002–2015 149 45 53 2 0
35
DMED data Clinically diagnosed cases, US Army, 2015–2019 757 41 38 8 13
*Estimated from data in article.
AK = Alaska, DMED = Defense Medical Epidemiology Database, NR = not reported, SM = Service Member, US = United States.
were compiled by sex, age, race, and military service for the Observational studies were considered only when they included
years 1997 to 2015. Incidence rates were calculated using the both frostbite cases and non-cases (i.e., had a control group).
entire population for each group (e.g., for women, incidence Many studies 30,42,43 examine factors among frostbite victims
rate = new female cases (n)/female population (n) × 100,000 only, and these are not appropriate because it is not known
per year). Figure 3 shows the overall incidence by sex, age, whether the incidence among cases might be similar to that of
race, service branch, and rank. Incidence was about 1.7 times non-cases for a particular factor.
higher for women compared with men (Figure 3A). Incidence
declined with age (Figure 3B). Blacks had an incidence rate Comparisons can be made from the literature regarding the
about 2.7 times higher than those of white or other ethnic- military frostbite risk factors mentioned above and in Figure 3.
ities (Figure 3C). The Army had the highest incidence rate Male sex has been associated with more frostbite risk in civil-
and the Navy the lowest, with the Army rate more than 7 ian samples, 33,44 and why this differs from the military (Figure
times higher than that of the Navy (Figure 3D). Incidence was 3A) is not clear. Data on age are not consistent; one popu-
highest in the lower ranks and decreased as rank increased lation-based study in Finland showed risk increasing with
(Figure 3E). age, while another showed risk of mild frostbite generally
33
decreasing with age. The higher risk among Blacks has been
44
A number of other studies have examined other risk factors duplicated in a number of military investigations. 26,45–47 During
for frostbite in military and civilian samples. Many stud- experimental cold exposure, Blacks (compared with whites)
ies 6,40,41 look at risk factors for any cold injury, but only stud- have a more protracted peripheral vasoconstriction, fewer va-
ies that have specifically addressed frostbite are included here. soconstriction/vasodilation cycles, less rapid rewarming, and

FIGURE 3 Incidence of frostbite in the
United States Military (1997–2015) by
sex (A), age (B), ethnicity (C), service (D),
and rank (E).
AF = Air Force, E = enlisted ranks,
MC = Marine Corps, O = officer ranks.

126 | JSOM Volume 20, Edition 4 / Winter 2020