9. General health
- 9.1 Aim
- 9.2 Research questions
- 9.3 Definitions of general health outcomes
- 9.4 Results
- 9.5 Discussion
9.1 Aim
The aim of this analysis is to investigate whether male Australian Defence Force personnel who served in the Gulf War have a higher rate of adverse general health outcomes than the comparison group; and, if so, whether these effects are associated with exposures and experiences that occurred in the Gulf War?
9.2 Research questions
1. Do Australian Gulf War veterans have more self-reported health symptoms than the comparison group?
2. Do Australian Gulf War veterans have more self-reported doctor diagnosed or treated medical conditions that were first diagnosed in 1991 or later than the comparison group?
3. Do Australian Gulf War veterans have more self-reported hospitalisations, functional impairment due to illness or injury, and current use of medication than the comparison group?
4. Do Australian Gulf War veterans have poorer general physical and mental health as measured by the SF-12 Health Survey than the comparison group?
5. Do Australian Gulf War veterans have poorer physical health status as measured by body mass index, waist circumference, waist-to-hip ratio, blood pressure, and a fitness test than the comparison group?
6. Where differences in risk of general health outcomes occur between Gulf War veterans and the comparison group, are these associated with exposures and experiences that occurred in the Gulf War?
9.3 Definitions of general health outcomes
These analyses were based on a number of self-reported general health measures such as symptoms and medical conditions, the Short-Form-12 Health Survey (SF-12) and objective physical examination measures such as body mass index (BMI), waist-to-hip ratio (WHR), blood pressure and a fitness test.
In the following description of the definitions used for measuring general health outcomes, the location of the relevant sections and questions of the postal questionnaire (eg G20. Recent health symptoms, q1-63) or medical examination data collection booklet are referred to.
9.3.1 Self-reported symptom definitions
To report the prevalence of self-reported symptoms in the past (G20. Recent health symptoms, q1-63), the response categories for each symptom were combined in two different ways:
- affected subjects were those who reported ‘mild’, ‘moderate’ or ‘severe’ symptoms (‘Mild, moderate or severe = Total Yes’). Non-affected subjects were those who responded ‘not at all’ (‘Not at all = No’);
- affected subjects were those who reported ‘moderate’ or ‘severe’ symptoms (‘Moderate or severe = Yes’). Non-affected subjects were those who responded ‘not at all’ or reported ‘mild’ symptoms (‘Not at all or mild = No’).
9.3.2 Self-reported medical conditions definitions
To report the prevalence of self-reported doctor diagnosed or treated medical conditions (G21. Diagnosed or treated medical conditions, q1-61), information on each reported medical condition was combined with reported year of first diagnosis in two different ways:
- affected subjects were those who reported having first been diagnosed with or treated for the condition in 1991 or later. Non-affected subjects reported never having been diagnosed with or treated for the condition. Subjects who reported being first diagnosed with or treated for the condition prior to 1991 were excluded from this analysis;
- affected subjects were those who reported having been first diagnosed with or treated for the condition in 1991 or later, and the diagnosis they reported was rated by a HSA doctor as ‘possible’ or ‘probable’. Non-affected subjects either reported never having been diagnosed with or treated for the condition, or reported having been first diagnosed with or treated for the condition in 1991 or later but the diagnosis they reported was rated by a HSA doctor as ‘non-medical’ or ‘unlikely’. Subjects who reported having been first diagnosed with or treated for the condition prior to 1991 were excluded from this analysis.
Correct classification of subjects as affected or non-affected depended critically on the accuracy of recall of events that occurred as many as 10 years previously. Restricting the self-reported medical conditions to those assessed by a HSA doctor as being a ‘possible’ or ‘probable’ diagnosis, rather than ‘non-medical’ or ‘unlikely’, was an attempt to improve the accuracy of classification (see chapter 5 for more detail on the ratings).
9.3.3 Hospitalisations, functional impairment and current use of medication
Hospitalisations were defined as:
- a positive response to question G23. “During the past twelve months have you been hospitalised overnight or longer because of illness or injury?”.
Functional impairment was defined as:
- a positive response to question G24. “Thinking back over the past two weeks, did you stay in bed or at home all or part of any day because you did not feel well or as a result of illnesses or injury?”
Current use of any medication was defined as:
- a positive response to question G25. “Are you currently taking any medicines including tablets, creams, inhalers, or other drugs?”
9.3.4 SF-12 Health Survey scoring
The SF-12 Health Survey physical (PCS-12) and mental (MCS-12) component summary scales were scored using US norm-based methods, with separate weights for the physical and mental scales.[258] Both summary scales use the same items but different weights. These weights were constructed by the developers of the SF-12 to produce PCS-12 and MCS-12 scores that would have a mean of 50 and a standard deviation of 10, if applied to the US general population.[258] If desired, scores can be interpreted in terms of the US general population mean of 50. US population norms were used in this report to allow results to be compared with other studies. The items in the scale refer to the four weeks prior to the completion of the questionnaire. The higher the score, the better the physical or mental health status.
9.3.5 Physical health status definitions
9.3.5.1 Body mass index
Body mass index (BMI) was defined as the weight in kilograms divided by the square of the height in metres (kg/m2) and classified according to the categories used by the National Nutrition Survey.[289]
| Categories | BMI kg/m2 | Risk of related health problems |
|---|---|---|
| Underweight |
<18.5
|
Low (but risk of other clinical problems increased) |
| Normal range |
18.5-<20.0 20-<25.0
|
Average |
| Overweight: |
>= 25.0
|
|
| Pre-obese |
25.0-<30.0
|
Increased |
| Obese class 1 |
30.0-<35.0
|
Moderate |
| Obese class 2 |
35.0-<40.0
|
Severe |
| Obese class 3 |
>= 40.0
|
Very severe |
9.3.5.2 Waist circumference and waist-to-hip ratio
Waist circumference, an indicator of increased risk of obesity related complications,[288, 292] was categorised as:
- ‘increased risk’ - >94 cm
- ‘substantially increased risk’ - >102 cm
Waist-to-hip ratio (WHR) was calculated by dividing each participant’s waist measurement by his hip measurement. A WHR of >0.9 was used to define those at health risk from having a central body fat distribution.[287]
9.3.5.3 Blood pressure
The average of the participant’s two systolic and diastolic blood pressure readings were categorised as representative of normal, high-normal or hypertensive blood pressure[294, 295] according to the categories shown inTable 9.2.
| Category | Systolic (mmHg) | Diastolic (mmHg) | |
|---|---|---|---|
| Normal |
<130
|
and
|
<85
|
| Optimal |
<120
|
and
|
<80
|
| High-normal |
130-139
|
or
|
85-89
|
| Hypertension |
>= 140
|
or
|
>= 90
|
| Grade 1 hypertension (mild) |
140-159
|
or
|
90-99
|
| Grade 2 hypertension (moderate) |
160-179
|
or
|
100-109
|
| Grade 3 hypertension (severe) |
>= 180
|
or
|
>= 110
|
| Isolated systolic hypertension |
>= 140
|
and
|
<90
|
Where a participant’s average systolic and diastolic blood pressure fell into two different categories, the higher category was applied. For example, if a participant’s average diastolic blood pressure was 88 mmHg and average systolic blood pressure was 145 mmHg, he would be categorised as Grade 1 hypertension.
9.3.6 Gulf War exposure measures
Where differences in risk of general health outcomes exist between Gulf War veterans and the comparison group, the analysis will investigate associations with several measures of exposure. The analysis will investigate whether risk of symptoms and medical conditions in either study group differs across subcategories of age, service type and rank. The analysis will also investigate whether risk of general health outcomes within the Gulf War veterans group differs according to the following exposures:
- Deployment completed before or after 17 January 1991 when the air strikes commenced
- Number of immunisations and clustering of immunisations
- Pyridostigmine bromide
- Antimalarials
- Anti-biological warfare tablets
- Pesticides/insecticides
- Repellents
- Being in an area where chemical weapons had been used
- Depleted Uranium
- Military Service Experience questionnaire score.
9.4 Results
9.4.1 Symptoms
Table 9.3 presents the prevalence of self-reported symptoms in the past month according to the two definitions of ‘mild, moderate or severe = Total Yes’ and ‘moderate or severe = Yes’, and ordered by decreasing prevalence in the Gulf War veteran group. The most common symptoms reported by Gulf War veterans were neuropsychological and musculoskeletal in nature. Gulf War veterans reported all symptoms more frequently than the comparison group, and this difference was statistically significant for all symptoms except those of low back pain, persistent cough, toothache, tender or painful swelling of lymph glands in neck, armpit or groin, vomiting, unintended weight loss greater than 4kg, and seizures or convulsions. The OR is a ratio that compares the odds that the symptom was reported by Gulf War veterans with the odds that members of the comparison group reported the symptom. When calculated with adjustment for these factors, the odds ratio (crude OR) is referred to in the tables as the adjusted odds ratio (Adj OR). Adjustment for potential confounders (age, service type, rank, marital status and education) made minor differences to the value of the odds ratio (OR).
Although there were some slight variations in the order, symptoms that were commonly reported by the Gulf War veteran group were also commonly reported by the comparison group (Figure 9.1).
Figure 9.1 Self-reported symptoms in last month by Gulf War deployment status
When only moderate or severe symptoms were considered (Table 9.3), the proportions of both groups reporting symptoms decreased to approximately one-quarter to one-half of those reporting ‘not at all or mild’ symptoms, and even more for some symptoms; indicating that the self-reported symptoms were dominated by relatively mild symptoms. For all symptoms except the rare conditions of skin ulcers and seizures or convulsions, the proportion of Gulf War veterans reporting symptoms remained higher than that of the comparison group. For most individual symptoms, the adjusted odds ratios for moderate and severe symptoms were higher than the adjusted odds ratios for any reported symptoms, indicating that when Gulf War veterans reported symptoms, they were more severe in nature. When moderate or severe symptoms only were considered, the adjusted odds ratios decreased for a number of symptoms (ringing in the ears, chest pain, shaking, loss of balance or coordination, loss of control over bladder or bowels, and burning sensation in the sex organs) and these were no longer significant.
Table 9.3 Prevalence and odds ratios (ORs) of self-reported symptoms in the past month ordered by decreasing prevalence in the Gulf War group
9.4.1.1 Comparison by service type
Table 9.4, Table 9.5 and Table 9.6 present the prevalence and odds ratios for symptoms most commonly reported by the Navy, Army and Air Force respectively, and ordered by decreasing prevalence in the Gulf War veteran group for each service type. The proportion of Navy Gulf War veterans reporting symptoms and the order of frequency they were reported in was very similar to that of the total Gulf War veteran group. This was to be expected, given the high representation of the Navy in the Gulf War group and its dominance of the pattern of symptom reporting.
The 15 symptoms most commonly reported across the service subgroups were similar. The six most common symptoms tended to be neuropsychological symptoms, and the odds ratios between the study groups for these symptoms were similar across the different service types. The symptoms were also common in the service subgroups of the comparison group. The relatively increased reporting of symptoms by Gulf War veterans was more marked in the younger (<20 year) age group (data not shown). The Army subjects in both study groups reported the common symptoms more frequently than the Navy and Air Force subjects. The order of frequency varied between the service types, and this was most marked in the Air Force compared with the Army and Navy. Within each service type, the proportion of Gulf War veterans reporting symptoms was greater than the comparison group for nearly all symptoms. These differences were statistically significant for all symptoms except low back pain in the Navy subgroup, were not significant for any symptoms in the Army subgroup, and were only significant for loss of concentration in the Air Force subgroup. When adjusted odds ratios for each symptom were compared across service types, no statistically significant differences emerged.
back to top| GWV | Comp grp | |||||
|---|---|---|---|---|---|---|
| Symptom | ‘Total Yes’ n (%) |
‘Total Yes’ n (%) |
Crude OR |
Adj OR* |
95% CI |
P value |
| Feeling unrefreshed after sleep |
814 (66)
|
617 (55)
|
1.6
|
1.6
|
1.4-2.0
|
<0.001
|
| Fatigue |
811 (66)
|
609 (54)
|
1.6
|
1.6
|
1.4-1.9
|
<0.001
|
| Headaches |
764 (62)
|
612 (55)
|
1.4
|
1.4
|
1.2-1.6
|
<0.001
|
| Sleeping difficulties |
732 (60)
|
528 (47)
|
1.7
|
1.7
|
1.4-2.0
|
<0.001
|
| Irritability / outbursts of anger |
707 (58)
|
510 (46)
|
1.6
|
1.6
|
1.4-1.9
|
<0.001
|
| General muscle aches or pains |
645 (53)
|
514 (46)
|
1.3
|
1.3
|
1.1-1.6
|
0.001
|
| Low back pain |
642 (52)
|
550 (49)
|
1.1
|
1.2
|
1.0-1.4
|
0.073
|
| Flatulence or burping |
575 (47)
|
444 (40)
|
1.3
|
1.4
|
1.2-1.6
|
<0.001
|
| Forgetfulness |
567 (46)
|
385 (46)
|
1.6
|
1.7
|
1.4-2.0
|
<0.001
|
| Difficulty finding the right word |
565 (46)
|
387 (34)
|
1.6
|
1.7
|
1.4-2.0
|
<0.001
|
| Loss of concentration |
531 (43)
|
312 (28)
|
2.0
|
2.0
|
1.7-2.4
|
<0.001
|
| Stiffness in several joints |
480 (39)
|
383 (34)
|
1.2
|
1.3
|
1.1-1.5
|
0.003
|
| Rash or skin irritation |
445 (36)
|
320 (29)
|
1.4
|
1.5
|
1.2-1.8
|
<0.001
|
| Pain, without swelling or redness, in several joints |
436 (35)
|
340 (30)
|
1.3
|
1.3
|
1.1-1.6
|
0.002
|
| Itchy or painful eyes |
426 (35)
|
298 (27)
|
1.5
|
1.5
|
1.3-1.8
|
<0.001
|
* Odds ratios are adjusted for service type, rank and age (< 20, 20-24, 25 to 34, >= 35 years), education and marital status.
back to top| GWV | Comp grp | |||||
|---|---|---|---|---|---|---|
|
Symptom
|
‘Total Yes’ n (%) |
‘Total Yes’ n (%) |
Crude OR | Adj OR† | 95% CI | P value |
| Feeling unrefreshed after sleep |
64 (74)
|
116 (68)
|
1.3
|
1.2
|
0.7-2.3
|
0.475
|
| Fatigue |
61 (70)
|
103 (60)
|
1.6
|
1.7
|
0.9-3.1
|
0.081
|
| Sleeping difficulties |
57 (66)
|
108 (63)
|
1.1
|
1.1
|
0.6-2.0
|
0.694
|
| Headaches |
55 (63)
|
97 (57)
|
1.3
|
1.3
|
0.8-2.3
|
0.332
|
| Irritability / outbursts of anger |
52 (60)
|
91 (53)
|
1.3
|
1.5
|
0.8-2.5
|
0.192
|
| General muscle aches or pains |
51 (61)
|
98 (57)
|
1.2
|
1.0
|
0.6-1.8
|
0.944
|
| Low back pain |
50 (58)
|
104 (60)
|
0.9
|
1.0
|
0.5-1.7
|
0.926
|
| Forgetfulness |
43 (50)
|
70 (41)
|
1.5
|
1.6
|
0.9-2.8
|
0.115
|
| Stiffness in several joints |
43 (49)
|
76 (44)
|
1.2
|
1.3
|
0.8-2.3
|
0.324
|
| Flatulence or burping |
42 (48)
|
75 (44)
|
1.2
|
1.3
|
0.8-2.3
|
0.313
|
| Difficulty finding the right word |
40 (47)
|
71 (41)
|
1.2
|
1.3
|
0.7-2.2
|
0.404
|
| Loss of concentration |
40 (46)
|
66 (38)
|
1.4
|
1.3
|
0.8-2.3
|
0.284
|
| Avoiding doing things or situations |
37 (43)
|
60 (35)
|
1.4
|
1.6
|
0.9-2.9
|
0.092
|
| Pain, without swelling or redness, in several joints |
37 (43)
|
67 (39)
|
1.2
|
1.3
|
0.7-2.2
|
0.429
|
| Itchy or painful eyes |
34 (39)
|
61 (36)
|
1.2
|
1.1
|
0.6-2.0
|
0.676
|
| Rash or skin irritation |
34 (39)
|
57 (33)
|
1.3
|
1.3
|
0.7-2.2
|
0.423
|
| Indigestion |
34 (39)
|
48 (28)
|
1.6
|
1.7
|
0.9-3.0
|
0.083
|
* 17 symptoms were listed because the prevalence of the last three symptoms were identical for Gulf War veterans.
† Odds ratios are adjusted for service type, rank and age (< 20, 20-24, 25 to 34, >= 35 years), education and marital status
back to top| GWV | Comp grp | |||||
|---|---|---|---|---|---|---|
|
Symptom
|
‘Total Yes’ n (%) |
‘Total Yes’ n (%) |
Crude OR |
Adj OR* |
95% CI | P value |
| Fatigue |
65 (62)
|
149 (59)
|
1.1
|
1.1
|
0.7-1.9
|
0.607
|
| Sleeping difficulties |
62 (59)
|
117 (46)
|
1.7
|
1.6
|
1.0-2.5
|
0.066
|
| Feeling unrefreshed after sleep |
59 (56)
|
129 (51)
|
1.2
|
1.2
|
0.7-1.9
|
0.462
|
| Headache |
53 (50)
|
119 (47)
|
1.2
|
1.1
|
0.7-1.8
|
0.665
|
| Low back pain |
51 (49)
|
103 (41)
|
1.3
|
1.3
|
0.8-2.1
|
0.304
|
| Irritability / outbursts of anger |
49 (47)
|
101 (40)
|
1.3
|
1.4
|
0.8-2.2
|
0.202
|
| Loss of concentration |
40 (38)
|
70 (28)
|
1.6
|
1.7
|
1.0-2.9
|
0.043
|
| General muscle aches or pains |
40 (38)
|
95 (38)
|
1.0
|
0.9
|
0.6-1.6
|
0.821
|
| Difficulty finding the right word |
38 (36)
|
85 (34)
|
1.1
|
0.9
|
0.6-1.5
|
0.766
|
| Flatulence or burping |
37 (35)
|
105 (42)
|
0.8
|
0.7
|
0.4-1.2
|
0.163
|
| Stiffness in several joints |
33 (31)
|
59 (23)
|
1.5
|
1.3
|
0.8-2.3
|
0.315
|
| Sore throat |
32 (30)
|
63 (25)
|
1.3
|
1.2
|
0.7-2.1
|
0.462
|
| Rash or skin irritation |
31 (30)
|
52 (21)
|
1.6
|
1.5
|
0.9-2.7
|
0.117
|
| Itchy or painful eyes |
30 (29)
|
65 (26)
|
1.2
|
1.1
|
0.7-1.9
|
0.639
|
| Indigestion |
30 (29)
|
58 (23)
|
1.3
|
1.3
|
0.8-2.3
|
0.308
|
* Odds ratios are adjusted for service type, rank and age (< 20, 20-24, 25 to 34, >= 35 years), education and marital status.
9.4.1.2 Total number of self-reported symptoms
The total number of symptoms reported by Gulf War veterans and the comparison group are shown in Table 9.7. Gulf War veterans were more likely than the comparison group to report a greater number of symptoms (>15) than the comparison group.
| Number of symptoms reported | Gulf War veterans n (%) |
Comparison group n (%) |
|---|---|---|
|
0
|
43 (3)
|
83 (5)
|
|
1-5
|
271 (19)
|
392 (25)
|
|
6-10
|
303 (21)
|
397 (26)
|
|
11-15
|
241 (17)
|
280 (18)
|
|
16-20
|
209 (15)
|
158 (10)
|
|
21-30
|
213 (15)
|
165 (11)
|
|
>30
|
141 (10)
|
69 (4)
|
The mean total number of self-reported symptoms was used as a summary measure of health symptoms that were self-reported by the study groups. Table 9.8 shows that the mean total number of symptoms reported by Gulf War veterans was 31 percent higher than for the comparison group overall, and was also greater for Gulf War veterans when the study groups were compared within subgroups of service type, rank and age. The mean total number of symptoms increased with age in the comparison group, but not in the Gulf War group. The difference between the Gulf War veterans and the comparison group in the mean total number of self-reported symptoms was greater in the younger age group (<20 years) and this difference decreased with age, approaching statistical significance across all the age groups (P=0.063). The differences between Gulf War veterans and the comparison group in the mean total number of self-reported symptoms tended to be greater in the ‘other ranks-non supervisory’, than in the ‘officer’ or ‘other ranks – supervisory’. However, the mean total number of symptoms was not statistically significantly different across subgroups of rank (P=0.087) or service type (P=0.164).
back to top| Total number of symptoms | ||||||
|---|---|---|---|---|---|---|
| Gulf War veterans | Comparison group | Crude ratio of means | Adjusted ratio of means (95% CI) * | P value | ||
| Mean (SD) | Mean (SD) | |||||
|
Total study population
|
14.7 (11.1) | 11.3 (9.2) | 1.3 | 1.3 (1.2-1.4) |
<0.001
|
|
| P value for interaction† | ||||||
|
Service type
|
||||||
| Navy |
14.9 (11.2)
|
11.2 (9.3)
|
1.3
|
1.3 (1.3-1.4)
|
 |
0.164
|
| Army |
16.6 (11.6)
|
14.1 (9.8)
|
1.2
|
1.1 (1.0-1.4)
|
||
| Air Force |
11.4 (9.7)
|
9.5 (8.0)
|
1.2
|
1.2 (1.0-1.5)
|
||
|
Rank
|
||||||
| Officer |
11.0 (8.5)
|
8.8 (7.9)
|
1.3
|
1.3 (1.1-1.5)
|
|
0.087
|
| Other ranks - supervisory |
15.1 (11.2)
|
12.5 (9.4)
|
1.2
|
1.3 (1.2-1.4)
|
||
| Other ranks – non-supervisory |
16.3 (11.9)
|
11.4 (9.6)
|
1.5
|
1.5 (1.3-1.6)
|
||
|
Age
|
||||||
| <20 years |
16.2 (11.7)
|
9.8 (8.6)
|
1.7
|
1.6 (1.4-2.0)
|
|
0.063
|
| 20 - <25 years |
14.5 (11.1)
|
10.8 (9.1)
|
1.3
|
1.3 (1.2-1.5)
|
||
| 25 - <35 years |
14.9 (10.9)
|
11.2 (8.7)
|
1.3
|
1.3 (1.2-1.4)
|
||
| >=35 years |
14.9 (11.5)
|
13.0 (10.9)
|
1.2
|
1.2 (1.0-1.4)
|
||
* Ratio of means are adjusted for service type, rank, age (< 20, 20-24, 25 to 34, >= 35 years), education and marital status by negative binomial regression.
† P values shown for service type, rank and age result from a test of whether the ratio of the meant total number of symptoms between Gulf War veterans and comparison group are the same at each level of service type, rank or age.
9.4.2 Medical conditions
9.4.2.1 Self-reported medical conditions first diagnosed in 1991 or later
Self-reported medical conditions first diagnosed in 1991 or later, and those that were first diagnosed in 1991 or later and were rated as a ‘possible’ or ‘probable’ diagnosis by a HSA doctor are shown in Table 9.9. The rating of the self-reported medical conditions by a HSA doctor as a ‘possible’ or ‘probable’ diagnosis was used to increase the accuracy of the self-reported medical conditions. The results of these latter analyses (right hand columns of Table 9.9 and bottom row of Table 9.13) included only those participants who completed a medical assessment and could, therefore, have their self-reported medical conditions in the postal questionnaire assessed by a HSA doctor. The self-reported medical conditions of all participants who completed a postal questionnaire, whether they subsequently had a medical assessment of not, were included in the remainder of the relevant analyses.
The most commonly reported medical conditions were of the musculoskeletal system, skin and psychological conditions. Most medical conditions were reported more frequently by Gulf War veterans than the comparison group. However, the increased reporting was statistically significant only for about half the medical conditions, and these involved several different body systems including the skin, psychological, gastrointestinal, respiratory, eye, nervous or ear, nose and throat systems. The strongest association was for posttraumatic stress disorder. The low prevalences and the resulting imprecision for many conditions limited further interpretation. Adjusted odds ratios were not able to be calculated for these rare medical conditions.
When self-reported medical conditions that were rated as a ‘possible’ or ‘probable’ condition were considered, the proportions of both groups reporting medical conditions decreased by a small amount. Most of the adjusted odds ratios were similar, suggesting that the proportions of medical conditions assessed by the doctors as ‘non-medical’ or ‘unlikely’ were similar between the two groups.
The differences between the Gulf War veteran and comparison groups in reporting of medical conditions (Figure 9.2) are less marked than the difference in the reporting of symptoms between the study groups that was illustrated in Figure 9.1.
Figure 9.2 Medical conditions first diagnosed in 1991 or later, with a prevalence of more than 2%, by study group
back to top
Table 9.9 Prevalence and ORs of self-reported doctor diagnosed or treated medical conditions first diagnosed in 1991 or later
Go to table 9.99.4.2.2 Comparison by service type
Table 9.10, Table 9.11 and Table 9.12 show the self-reported doctor diagnosed or treated medical conditions first diagnosed in 1991 or later that were most commonly reported within each of the service types. Some conditions such as back or neck problems, joint problems, any other skin problems, hearing loss, anxiety stress or depression, eye or vision problems, bowel disorder, and sinus problems were consistently reported by all service types in their ten most commonly reported conditions. Other medical conditions were reported in the top ten for only some of the service types. These included ear infection in the Navy, but not in the Army or Air Force subgroups; posttraumatic stress disorder in the Army; hay fever and other skin cancer in the Air Force and high blood pressure in the Navy and Army, but not the other service types respectively.
Although the proportions of Gulf War veterans in the service subgroups reporting medical conditions with an onset in 1991 or later were greater than their comparison groups for most of the medical conditions (except eye or vision problems in the Army and Air Force, and any other skin problem in the Air Force) the differences are significant for only some of the conditions. The odds ratios differ significantly across the services for only one medical condition, eye or vision problems (p=0.024).
back to top|
Medical Condition
|
GWV n (%) |
Comp grp n (%) |
Crude OR |
Adj OR* |
95% CI | P value |
|---|---|---|---|---|---|---|
| Back or neck problems |
299 (28)
|
266 (29)
|
1.0
|
1.0
|
0.8-1.2
|
0.942
|
| Joint problems |
244 (22)
|
186 (19)
|
1.2
|
1.2
|
1.0-1.5
|
0.050
|
| Any other skin problem |
177 (16)
|
119 (12)
|
1.4
|
1.4
|
1.1-1.8
|
0.007
|
| Hearing loss |
162 (14)
|
151 (15)
|
1.0
|
1.0
|
0.8-1.3
|
0.975
|
| Anxiety, stress or depression |
171 (14)
|
135 (12)
|
1.2
|
1.3
|
1.0-1.6
|
0.058
|
| Eye or vision problems (eg glaucoma) |
147 (13)
|
87 (9)
|
1.6
|
1.6
|
1.2-2.1
|
0.001
|
| Bowel disorder (eg diarrhoea, constipation, bleeding) |
130 (11)
|
111 (11)
|
1.0
|
1.1
|
0.8-1.4
|
0.698
|
| Sinus problems |
114 (10)
|
76 (8)
|
1.4
|
1.4
|
1.0-1.9
|
0.031
|
| High blood pressure |
103 (9)
|
85 (8)
|
1.1
|
1.1
|
0.8-1.5
|
0.411
|
| Ear infection |
92 (9)
|
67 (7)
|
1.3
|
1.2
|
0.9-1.7
|
0.218
|
* Odds ratios are adjusted for rank, age (< 20, 20-24, 25 to 34, >= 35 years), education and marital status.
|
Medical Condition
|
GWV n (%) |
Comp grp n (%) |
Crude OR | Adj OR* | 95% CI | P value |
|---|---|---|---|---|---|---|
| Back or neck problems |
27 (40)
|
47 (40)
|
1.0
|
1.1
|
0.6-2.1
|
0.785
|
| Joint problems |
20 (34)
|
42 (33)
|
1.0
|
1.1
|
0.6-2.2
|
0.773
|
| Any other skin problem |
17 (23)
|
20 (14)
|
1.9
|
2.0
|
1.0-4.3
|
0.063
|
| Anxiety, stress or depression |
19 (23)
|
20 (12)
|
2.1
|
2.1
|
1.0-4.4
|
0.036
|
| High blood pressure |
15 (17)
|
15 (9)
|
2.1
|
2.0
|
0.9-4.6
|
0.102
|
| Bowel disorder (eg diarrhoea, constipation, bleeding) |
12 (15)
|
13 (8)
|
1.9
|
2.6
|
1.1-6.5
|
0.037
|
| Sinus problems |
11 (15)
|
7 (5)
|
3.4
|
3.4
|
1.2-9.9
|
0.023
|
| Hearing loss |
11 (15)
|
23 (15)
|
0.9
|
0.9
|
0.4-1.9
|
0.711
|
| Post Traumatic Stress Disorder |
12 (14)
|
8 (5)
|
3.3
|
4.1
|
1.5-11.5
|
0.007
|
| Eye or vision problems (eg glaucoma) |
9 (12)
|
25 (17)
|
0.7
|
0.6
|
0.3-1.5
|
0.265
|
* Odds ratios are adjusted for rank, age (< 20, 20-24, 25 to 34, >= 35 years), education and marital status
|
Medical Condition
|
GWV
n (%) |
Comp grp
n (%) |
Crude OR
|
Adj OR*
|
95% CI
|
P value
|
|---|---|---|---|---|---|---|
|
Back or neck problems
|
27 (33)
|
57 (30)
|
1.2
|
1.1
|
0.6-1.9
|
0.799
|
|
Joint problems
|
15 (17)
|
34 (15)
|
1.1
|
1.0
|
0.5-2.0
|
0.946
|
|
Other skin cancer (eg
squamous cell or basal cell skin cancers) |
15 (15)
|
31 (13)
|
1.2
|
1.1
|
0.6-2.2
|
0.787
|
|
Any other skin problem
|
13 (13)
|
33 (15)
|
0.9
|
0.8
|
0.4-1.8
|
0.656
|
|
Hearing loss
|
12 (13)
|
27 (12)
|
1.1
|
0.9
|
0.4-1.9
|
0.751
|
|
Anxiety, stress or depression
|
13 (12)
|
29 (12)
|
1.1
|
1.1
|
0.5-2.3
|
0.870
|
|
Sinus problems
|
11 (12)
|
17 (8)
|
1.6
|
1.1
|
0.5-2.7
|
0.784
|
|
Bowel disorder (eg diarrhoea, constipation, bleeding)
|
11 (11)
|
18 (8)
|
1.5
|
1.3
|
0.5-2.9
|
0.596
|
|
Hayfever
|
8 (9)
|
17 (8)
|
1.1
|
1.2
|
0.5-3.1
|
0.680
|
|
Eye or vision problems
(eg glaucoma) |
9 (9)
|
25 (11)
|
0.8
|
0.8
|
0.3-1.9
|
0.583
|
* Odds ratios are adjusted for rank, age (< 20, 20-24, 25 to 34, >= 35 years), education and marital status.
back to top9.4.2.3 Total number of self-reported medical conditions
One thousand one hundred and thirty-six (80%) Gulf War veterans reported at least one, and 146 (10%) reported more than five, medical conditions that had been first diagnosed in 1991 or later. One thousand one hundred and eighty-six (77%) comparison group subjects reported at least one, and 99 (6%) reported more than five, medical conditions that had been first diagnosed in 1991 or later (data not tabulated).
Gulf War veterans reported a maximum of 22, and the comparison group a maximum of 13, medical conditions first diagnosed in 1991 or later. Gulf War veterans reported a maximum of 21, and the comparison group a maximum of 11, medical conditions first diagnosed in 1991 and rated as a ‘possible’ or ‘probable’ diagnosis by a HSA doctor (data not tabulated).
The mean total number of self-reported medical conditions was used as a summary measure to compare the reporting of medical conditions between the study groups, and these are shown in Table 9.13. Gulf War veterans reported an increased mean total number of self-reported medical conditions than the comparison group. This was regardless of whether these conditions were first diagnosed in 1991 or since, or whether the conditions were first diagnosed in 1991 or since and had been rated as a ‘possible’ or ‘probable’ diagnosis by a HSA doctor and were thus considered to be more accurate diagnoses. Gulf War veterans reported 20% more medical conditions first diagnosed in 1991 or later and 17% more ‘possible’ or ‘probable’ medical conditions first diagnosed in 1991 or later.
|
Mean total number of medical conditions
|
|||||
|---|---|---|---|---|---|
|
Gulf War veterans
|
Comparison group
|
Crude ratio of means
|
Adjusted ratio of means * (95% CI)
|
P value
|
|
|
Mean (SD)
|
Mean (SD)
|
|
|
|
|
|
First diagnosed in 1991 or later
|
2.4 (2.4)
|
2.0 (2.0)
|
1.2
|
1.2 (1.1-1.3)
|
<0.001
|
|
‘Possible’ or ‘probable’ medical
conditions first diagnosed in 1991 or later †
|
2.2 (2.2)
|
1.9 (1.8)
|
1.1
|
1.2 (1.1-1.3)
|
<0.001
|
* Ratios of means are adjusted for service type, rank
and age (< 20, 20-24, 25 to 34, >= 35 years), education and marital
status by negative binomial regression
† Includes only those participants who completed a medical assessment
and could, therefore, have their self-reported medical condition in the
postal questionnaire assessed by a HSA doctor.
9.4.2.4 Doctor’s assessment of the likelihood of self-reported medical conditions
One thousand and ninety-four Gulf War veterans and 1043 comparison group subjects reported 3265 and 2770 medical conditions respectively, which were subsequently assessed by the HSA doctors for the likelihood of the diagnosis. The results are shown in Table 9.14. These results excluded 351 medical conditions reported by 209 subjects who did not attend for a HSA medical assessment and 214 medical conditions reported by 132 subjects who did attend for a HSA medical assessment but for which the doctor’s assessment was missing.
| Gulf War veterans Number of medical conditions (%) |
Comparison group Number of medical conditions (%) |
P value† |
||
|---|---|---|---|---|
|
HSA doctor’s assessment of the diagnosis
|
||||
|
Non-medical
|
165 (5.1)
|
98 (3.5)
|
 |
0.016 |
|
Unlikely
|
119 (3.6)
|
87 (3.1)
|
||
|
Possible
|
528 (16.2)
|
418 (15.1)
|
||
|
Probable
|
2453 (75.1)
|
2167 (78.2)
|
* n=number of medical conditions
† The P value is for an ordered table of all non-missing values, ie excluding doctor’s assessment code missing, adjusting for clustering arising from multiple self-reported diagnoses within the same individual.
For the Gulf War veteran group, 2981 out of 3265 (91.3%) medical conditions were assessed as ‘possible’ or ‘probable’ diagnoses, and for the comparison group 2585 out of 2770 (93.3%) medical conditions were assessed as ‘possible’ or ‘probable’. Less than 10% of the diagnoses in both study groups were assessed as a ‘non-medical’ or ‘unlikely’ diagnoses. This proportion was slightly greater in the Gulf War veteran group (8.7% vs 6.6%).
back to top9.4.2.5 Self-reported doctor medical conditions first diagnosed in 1990 or earlier
Self-reported medical conditions first diagnosed in 1991 or later are of prime interest in this study in relation to Gulf War deployment. Self-reported medical conditions first diagnosed in 1990 or earlier, ie medical conditions defined in this study as having an onset prior to the Gulf War were also compared to estimate differences in pre-Gulf War morbidity between the two study groups (data not tabulated).
The comparison group reported many conditions that were first diagnosed in 1990 or earlier more commonly than the Gulf war veterans. These self-reported medical conditions included high blood pressure, heart disease, migraines, infections such as pneumonia, hepatitis, or other significant infections, kidney, bladder and bowel disorders, back, neck and joint problems, ear infections, hearing loss, almost all skin diseases other than dermatitis or eczema, some psychological conditions such as anxiety, stress or depression, hay fever, food allergy, diseases of the genital organs, and low fertility. The difference in prevalence ranged from 0.4% for heart disease to 5.0% for back or neck problems.
There were few conditions, such as dermatitis or eczema, skin cancers other than malignant melanoma, and asthma for which the proportion of Gulf War veterans reporting the medical conditions was greater than the comparison group.
Many of the self-reported medical conditions first diagnosed in 1990 or earlier were of low prevalence in both study groups. Some other medical conditions, such as bowel disorder, any significant infections, back, neck or joint problems, ear infection, hearing loss, some skin problems, hayfever, and any diseases of the genital organ had a prevalence greater than 5% in at least one of the study groups.
Therefore these findings suggests that pre-Gulf war, both study groups were very healthy, but that the comparison group was reportedly a little healthier than the Gulf War group.
9.4.3 Hospitalisations, functional impairment due to illness or injury, and current use of medication
The results of the assessment of hospitalisations during the past twelve months, functional impairment due to illness or injury, and current use of medication are shown in Table 9.15.
The pattern of the number of days of hospitalisations, reported by the two study groups, was very similar. The median number of days hospitalised in the last 12 months was three days for Gulf War veterans (range 1-70) and two days (range 1-240) for the comparison group. If the one comparison group subject who reported spending 240 days in hospital during the past year was excluded, the ranges for days in hospital were similar for the Gulf War veterans and comparison group (1-70 days vs 1-86 days in hospital).
The mean (SD) number of days hospitalised for Gulf War veterans 0.14 (0.45) days was similar to that of the comparison group 0.13 (0.43) days. The crude ratio of the mean number of hospitalisations was 1.07. Adjustment for possible confounders made little difference, and the adjusted ratio of means of 1.11 (95% CI 0.87-1.42) was not statistically significant (P=0.407).
A significantly greater proportion of Gulf War veterans reported functional impairment over the past two weeks (21% vs 17%). The proportions of Gulf War veterans and comparison group reporting current use of medication (35% vs 33%) were similar.
|
GWV n (%)
|
Comp grp n (%)
|
Crude OR
|
Adj OR*
|
95% CI
|
P value
|
|
|---|---|---|---|---|---|---|
|
Hospitalisations
|
||||||
|
None
|
1269 (89.4)
|
1383 (89.9)
|
||||
|
1 hospitalisation
|
114 (8.0)
|
126 (8.2)
|
||||
|
2 hospitalisations
|
28 (2.0)
|
21 (1.4)
|
||||
|
3 hospitalisations
|
6 (0.4)
|
6 (0.4)
|
||||
|
4 hospitalisations
|
2 (0.1)
|
3 (0.2)
|
||||
|
Any hospitalisation
|
150 (10.6)
|
156 (10.1)
|
1.1
|
1.3
|
0.8-1.3
|
0.793
|
|
Functional impairment
|
||||||
|
Total number who stayed at home
|
295 (20.8)
|
256 (16.6)
|
1.3
|
1.3
|
1.1-1.6
|
0.004
|
|
Medication use
|
||||||
|
Current use of any kind of medication
|
493 (35.0)
|
515 (33.4)
|
1.1
|
1.1
|
1.0-1.3
|
0.144
|
* Odds ratios are adjusted for service type, rank and age (< 20, 20-24, 25 to 34, >= 35 years), education and marital status by negative binomial regression
back to top9.4.4 SF-12 Health Survey
Figure 9.3 and Figure 9.4 show the distributions of the PCS-12 and MCS-12 in Gulf War veterans and comparison groups, which are both skewed to the left. The differences in distributions between the groups were more marked for the MCS-12.
Figure 9.3 Distributions of the PCS-12 score of the SF-12 Health Survey
Figure 9.4 Distributions of the MCS-12 score of the SF-12 Health Survey
Table 9.16 shows the mean scores of the PCS-12 and the MCS-12 for the total study population and the service subgroups. Across the total study population and within the Navy subgroup, Gulf War veterans recorded poorer physical health and mental health scores. Army subjects in both groups scored more poorly on both the PCS-12 and the MCS-12 compared with the Navy and Air Force subjects, with mean scores below the US population mean of 50. Army Gulf War veterans recorded significantly poorer MCS-12 scores than the comparison group. Analyses using median scores provided very similar results.
back to top|
SF-12 score
|
|||||
|---|---|---|---|---|---|
|
GWV
|
Comparison
group |
Crude
difference between means |
Adjusted
difference* (95% CI) |
P value
|
|
|
Total study population
|
|||||
|
PCS-12 mean (SD)
|
49.2 (9.2)
|
49.9 (9.0)
|
-0.7
|
-0.9
(-1.6, -0.2) |
0.008
|
|
MCS-12 mean (SD)
|
47.4 (11.2)
|
50.9 (9.5)
|
-3.5
|
-3.4
(-4.2, -2.6) |
<0.001
|
|
Navy
|
|||||
|
PCS-12 mean (SD)
|
49.2 (9.0)
|
50.0 (8.6)
|
-0.8
|
-1.0
(-1.7, -0.3) |
0.006
|
|
MCS-12 mean (SD)
|
47.3 (11.1)
|
51.0 (9.4)
|
-3.7
|
-3.7
(-4.5, -2.8) |
<0.001
|
|
Army
|
|||||
|
PCS-12 mean (SD)
|
47.6 (10.6)
|
45.9 (11.7)
|
1.7
|
0.9
(-2.1, 3.9) |
0.554
|
|
MCS-12 mean (SD)
|
45.6 (12.4)
|
49.9 (10.6)
|
-4.3
|
-4.2
(-7.2, -1.2) |
0.006
|
|
Air Force
|
|||||
|
PCS-12 mean (SD)
|
50.4 (9.8)
|
52.4 (7.7)
|
-2.0
|
-1.8
(-3.8, 0.2) |
0.084
|
|
MCS-12 mean (SD)
|
50.3 (10.9)
|
51.1 (9.4)
|
-0.8
|
-0.5
(-2.8, 1.9) |
0.706
|
* Difference between means are adjusted for service type, rank and age (< 20, 20-24, 25 to 34, >= 35 years), education and marital status by linear regression.
Additional analyses (data not tabulated) indicated that the MCS-12 results differed by rank. The difference in mean MCS-12 scores between the Gulf War veteran and comparison groups was greatest for the ‘other ranks – non supervisory’ subgroup, where the difference (-5.3) was about twice as great as the differences in means for the ‘officer’ (-2.5) and ‘other ranks – supervisory’ (-2.6) subgroups (P value for interaction =0.006). Similarly, the MCS-12 results differed by age group, with differences in MCS-12 means between Gulf War veterans and comparison group of -7.1 for age <20 years and -1.9 for age >=35 years (p=0.004). The linear decrease in group differences with age was significant (p=0.024). The differences in mean MCS-12 scores between the Gulf War veteran and comparison groups by service type were less marked. The difference in means for the Army (-4.3), Navy (-3.7) and Air Force (-0.8) were not statistically significantly different (P=0.069) across the service subgroups. The PCS-12 results did not differ for the subgroups in the comparison of Gulf War and comparison groups.
To compare the proportions of subjects with very low SF-12 scores, the proportion of Gulf War veterans and comparison group subjects in our study who fell below the US 25th percentile of the SF-12 score were compared. This analysis extended the approach of a previous study of Gulf War veterans,[249] and the results are shown in Table 9.17. A significantly greater proportion of Gulf War veterans have PCS-12 and MCS-12 scores that are lower than the 25th percentile for the US population norms than the comparison group (Table 9.17). A significantly greater proportion of Navy (adjusted OR 2.0) and Army (adjusted OR 2.2), but not Air Force (adjusted OR 0.9) Gulf War veterans have an MCS-12 score that was lower than the 25th percentile than the comparison group (P value for interaction =0.045). The decreasing odds ratio for MCS-12 with increasing age (p=0.046), with a decrease in odds ratios of OR=3.1 for age <20 years to OR=1.4 for age >=35 years, indicted greater risk of poorer mental health in younger Gulf War veterans. No similar age or service type patterns emerged for the PCS-12.
|
Scores below US 25th percentile*
|
|||||
|---|---|---|---|---|---|
|
GWV
n (%) |
Comp grp
n (%) |
Crude OR
|
Adjusted OR†
(95% CI) |
P value
|
|
|
Total study population
|
|||||
|
PCS-12
|
401 (29)
|
377 (25)
|
1.2
|
1.3 (1.1, 1.6)
|
0.001
|
|
MCS-12
|
476 (35)
|
338 (22)
|
1.8
|
1.9 (1.6, 2.2)
|
<0.001
|
* US 25th percentiles are 45.13 for MCS-12
and 46.53 for PCS-12.
† Odds ratios are adjusted for service type, rank and age (< 20,
20-24, 25 to 34, >= 35 years), education and marital status.
9.4.5 Physical measures of general health
9.4.5.1 Height, weight, body mass index, waist and hip circumference and waist-to-hip ratio
The mean height of both study groups was identical (Table 9.18). The mean weight, BMI, hip and waist circumferences of Gulf War veterans and the comparison group were very similar.
|
GWV
|
Comp grp
|
|||||||
|---|---|---|---|---|---|---|---|---|
|
mean
|
(SD)
|
mean
|
(SD)
|
Crude OR
|
||||