5.4 General physical and mental health
The Short Form-12 Health Survey (SF12) was administered at both baseline and follow up to
facilitate longitudinal comparisons of participants’ self-perceived physical and mental health
status.
5.4.1 Self-perceived physical and mental health status at follow up
Figure 14 SF12 Physical and Mental Component Summary scores at follow up
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The charts in Figure 14 show the distribution of the SF12 Physical Component Summary
(PCS) and Mental Component Summary (MCS) scores at follow up for both the Gulf War
veterans and the comparison group. Higher scores represent higher perceived health status.
The distributions for both the PCS and MCS in both groups were left skewed, with larger
numbers of participants reporting high scores than low scores. The distributions were less
skewed in the Gulf War veteran group, with these participants more likely than the
comparison group participants to report mid-range PCS and MCS scores.
Table 19 SF12 Physical and Mental Component Summary scores at follow up
SF12 subscale
score
Gulf War veterans
(N=670)
mean (sd)
Physical
Component
Summary
Mental
Component
Summary
Comparison group
(N=642)
mean (sd)
mean diff
Adj mean diff (95% CI)
46.68 (10.30)
48.18 (9.76)
-1.50
-1.34 (-2.42, -0.26)
46.12 (11.85)
49.92 (10.67)
-3.80
-3.32 (-4.57, -2.06)
Comparing the two groups on mean PCS and MCS scores at follow up, Table 19 shows that
the Gulf War veterans reported significantly poorer physical health status and mental health
status than the comparison group, with a greater difference found for the mental component
score.
5.4.2 Association between Gulf War-deployment characteristics and
self-perceived physical and mental health in veterans at follow up
The associations between Gulf War deployment characteristics and self-perceived physical
health at follow up, as measured by the SF12 PCS, are shown in Table 20 for male Gulf War
veterans. Significantly poorer self-perceived physical health status at follow up was
associated with older age at deployment and with ranks lower than Officer. There were no
significant differences in self-perceived physical health across Gulf War veterans from
different service branches.
The associations between Gulf War deployment characteristics and self-perceived mental
health at follow up, as measured by the SF12 MCS, are shown in Table 21 for male Gulf
War veterans. None of the differences were statistically significant, however lower self-
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perceived mental health status in ‘other ranks, non-supervisory’ and younger age at
deployment approached statistical significance; p = 0.10 and p = 0.08 respectively.
Table 20 Association between Gulf War-deployment characteristics and SF12 Physical
Component Summary sores at follow up in Gulf War veterans
Gulf War deployment
characteristic
Age at deployment
< 20
20-24
25-34
>=35
Service branch
Navy
Army
Air Force
Rank category
Officer
Other rank-supervisory
Other rank -non supervisory
Mean SF12 PCS score for Gulf War veterans at follow up
N
mean (sd)
diff
Adj diff (95% CI)
58
165
351
96
47.28 (9.80)
48.13 (10.49)
46.54 (10.11)
44.34 (10.66)
0.00
0.85
-0.74
-2.94
0.00
-0.47 (-3.65, 2.71)
-3.70 (-7.19, -0.21)
-7.11 (-11.10, -3.12)
577
44
49
46.73 (10.33)
44.85 (10.20)
47.75 (9.97)
0.00
-1.87
1.02
0.00
-2.01 (-5.20, 1.18)
0.43 (-2.34, 3.21)
142
341
186
49.36 (9.53)
45.83 (10.24)
46.20 (10.69)
0.00
-3.53
-3.16
0.00
-4.55 (-6.46, -2.65)
-6.78 (-9.47, -4.08)
Table 21 Association between Gulf War-deployment characteristics and SF12 Mental
Component Summary sores at follow up in Gulf War veterans
Gulf War deployment
characteristic
Age at deployment
< 20
20-24
25-34
>=35
Service branch
Navy
Army
Air Force
Rank category
Officer
Other rank-supervisory
Other rank -non supervisory
Mean SF12 MCS score for Gulf War veterans at follow up
N
mean (sd)
diff
Adj diff (95% CI)
58
165
351
96
41.23 (11.85)
45.71 (12.67)
46.63 (11.40)
47.93 (11.41)
0.00
4.48
5.40
6.70
0.00
3.32 (-0.46, 7.10)
3.05 (-1.05, 7.16)
3.93 (-0.84, 8.69)
577
44
49
45.97 (11.85)
48.46 (11.90)
45.84 (11.84)
0.00
2.49
0.14
0.00
1.78 (-1.98, 5.55)
-1.15 (-4.69, 2.38)
142
341
186
47.49 (11.77)
47.03 (11.38)
43.45 (12.42)
0.00
-0.45
-4.04
0.00
-0.27 (-2.66, 2.12)
-2.91 (-6.34, 0.51)
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5.4.3 Change in self-perceived physical and mental health status
since baseline
In both study groups, participants’ self-perception of their physical health, as represented by
their PCS scores, and mental health, as represented by their MCS scores, decreased in the
period from baseline to follow up. These differences within groups across time were
statistically significant. Additional analysis showed that there was no difference between the
two groups in regard to change over time on either subscale (PCS: diff -0.67, adj diff -0.67,
95% CI -1.69, 0.35; MCS: diff -0.36; adj diff -0.16, 95% CI (-1.45, 1.13).
Table 22 SF12 Physical and Mental Component Summary mean scores at baseline and follow
up for participants who completed the SF12 at both time points
PCS
MCS
Baseline
mean (sd)*
49.41 (9.07)
48.07 (10.86)
Gulf War veterans (N=652
Follow up
mean diff (95% CI)
mean (sd)*
-2.68 (-3.38, -1.97)
46.72 (10.29)
-1.80 (-2.69, -0.91)
46.18 (11.85)
Baseline
mean (sd)*
50.34 (8.71)
51.56 (9.12)
Comparison group (N=624)
Follow up
mean diff (95% CI)
mean (sd)*
-2.01 (-2.72, -1.29)
48.32 (9.70)
-1.64 (-2.55, -0.73)
50.03 (10.61)
* Includes only those participants who also completed the SF12 at follow up
5.4.4 Key findings
In both study groups, participants completing the SF12 were more likely to report high selfperceived physical and mental health scores than low scores. However, Gulf War veteran
participants were more likely than the comparison group participants to report mid-range
physical health and mental health scores. Comparing the two groups on SF12 mean PCS
and MCS scores, Gulf War veterans reported significantly poorer physical health status and
significantly poorer mental health status than the comparison group, with the greater
difference being for the mental component scale.
Amongst Gulf War veterans, poorer self-perceived physical health status at follow up, but not
mental health status, was associated with older age at deployment and with ranks lower than
Officer. There were no significant differences in self-perceived physical or mental health at
follow up across Gulf War veterans from different service branches.
In both study groups, participants’ self-perception of their physical health and mental health
declined in the time period from baseline to follow up to a similar degree.
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