5.10
Respiratory health
Respiratory health was assessed at both baseline and follow up. There were some
differences between the two studies, however, in regard to the scope of respiratory health
data collected and the mode of data collection, which limited our ability to assess change
over time on those variables. At follow up a brief list of respiratory symptoms and medical
conditions were assessed via self-report questionnaire. The questions included at follow up
were pared down or modified from a larger set of respiratory symptom and condition
questions administered by a nurse in the baseline study. The baseline study also included
lung function testing using a spirometer, which was not included at follow up. The follow up
study included an assessment of respiratory health medications dispensed to participants
under the PBS or RPBS, which was not included at baseline.
5.10.1
Respiratory symptoms and conditions at follow up
The respiratory symptoms and conditions assessed at follow up are shown in Table 1. Gulf
War veterans were statistically significantly more likely than the comparison group to report
all measured symptoms of wheeze, cough and sputum. The difference between groups was
the greatest in magnitude for morning cough, with Gulf War veterans 67% more likely than
the comparison group to report this symptom. Whilst statistical significance was not
achieved for the differences between groups on the respiratory conditions shown in Table 1,
such as measures of doctor diagnosed asthma, chronic bronchitis and emphysema or
Chronic Obstructive Pulmonary Disease (COPD), the pattern was such that all point
estimates were higher in the Gulf War veteran group. The greatest difference was for COPD,
but numbers were very small.
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Table 1 Self-reported respiratory symptoms and medical conditions at follow up
Gulf War
veterans (N=659)
Comparison group
(N=697)
n (%)
n (%)
RR
Adj RR* (95% CI)
182 (26.73)
106 (16.43)
1.63
1.44 (1.15-1.80)
Wheeze with breathlessness
96 (55.17)
43 (43.43)
1.27
1.34 (1.02-1.75)
Wheeze present but not a cold
134 (77.91)
65 (64.36)
1.21
1.23 (1.03-1.47)
Woken by nocturnal cough in last 12
months
201 (29.26)
133 (20.46)
1.43
1.37 (1.11-1.69)
Morning cough
127 (18.35)
71 (10.99)
1.67
1.67 (1.26-2.23)
Day or night time cough
166 (24.16)
108 (16.64)
1.45
1.36 (1.09-1.70)
Symptom-based definition of
Chronic bronchitis§
144 (20.78)
84 (12.90)
1.61
1.51 (1.17-1.96)
Morning sputum in Winter
156 (23.01)
99 (15.57)
1.48
1.38 (1.10-1.74)
Day or night time sputum in Winter
160 (23.85)
110 (17.32)
1.38
1.31 (1.06-1.63)
Sputum most days for 3 months in
two successive years
105 (66.04)
52 (47.71)
1.38
1.31 (1.04-1.65)
Self-reported asthma
100 (14.41)
80 (12.18)
1.18
1.13 (0.86-1.50)
Self-reported doctor confirmed
asthma
87 (12.57)
73 (11.18)
1.12
1.09 (0.81-1.47)
Asthma attack in last 12 months
33 (33.33)
16 (20.78)
1.60
1.56 (0.89-3.74)
Currently taking asthma
medication†
42 (42.42)
23 (30.26)
1.40
1.42 (0.91-2.21)
Self-reported doctor confirmed
Chronic bronchitis
75 (10.84)
69 (10.57)
1.03
1.03 (0.74-1.43)
Self-reported doctor confirmed
emphysema or COPD‡
8 (1.15)
4 (0.61)
1.89
2.14 (0.60-7.66)
Respiratory symptoms and medical
conditions
Wheeze in last 12 months
* Adjusted for age (<20; 20-24; 25-34; >=35 years), service branch (Navy; Army; Air Force) and rank (CO, NCO, enlisted
ranks), each estimated as at August 1990, any atopy at baseline and current smoking status (never; former; current smoker)
† 5 participants who reported taking asthma medication did not specify which ones they took.
‡ COPD is Chronic Obstructive Pulmonary Disease
§ Defined as morning, day or night time cough for as much as three months in each of the previous two years
Prescribed respiratory health medications recorded on the PBS and RPBS
Where participants had provided consent, linked PBS and RPBS data was evaluated to
determine the prevalence of participants who had been dispensed a medication for
obstructive lung disease, including asthma and COPD, since the baseline study and in the
past 12 months. In adults, the majority of inhaled corticosteroids are prescribed in
combination with long-acting B-agonists, e.g. Fluticasone/Salmeterol (Seretide) or
Budesonide/Eformoterol (Symbicort), and administered through inhalers, or puffers. In the PBS
and RPBS it was not possible to distinguish between medications dispensed for asthma from
those for other obstructive lung diseases, such as COPD.44 However, for these combination
inhalers the dispensed price is greater than or equal to the co-payment for those without a
concession card, therefore all prescriptions, regardless of concession card possession, are
captured in the database44 and were used to compare use of medications for obstructive
airways disease including asthma and COPD in the two study groups. Medications such as
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short-acting beta-agonists, e.g. Ventolin inhalers and about half of the inhaled
corticosteroids, cost less than the PBS copayment amount for general patients and do not
appear on the PBS or are only subsidised by the PBS when the patient is a concession
cardholder. Therefore these medications were not compared. Tiotropium bromide (Spiriva)
is a long acting inhaled anticholinergic approved only for use in treatment of COPD and this
was also used to compare use of medication for COPD44 in the two study groups.
The PBS and/or RPBS data showed that 44 Gulf War veterans (8.2%) and 32 comparison
group members (6.5%) had been dispensed a medication listed under the ATC code R03AK
for “Adrenergics and other drugs for obstructive airway diseases” or Tiotropium (ATC code
R03BB) in the period since the baseline study. In the 12 month period prior to the follow up
study only 3.5% of Gulf War veterans and 2.4% of the comparison group had been
dispensed one of these medications and this difference between the groups was not
significant (RR 1.45, adj RR 1.19, 95% CI 0.59-2.41).
5.10.2
Key findings
Respiratory symptoms in relation to wheeze, cough and sputum were all reported
significantly more frequently by Gulf War veterans than the comparison group. Self-reported
doctor-confirmed respiratory medical conditions including asthma, chronic bronchitis and
emphysema or COPD were also reported more frequently by Gulf War veterans, but these
differences between groups were not statistically significant. There was no significant
difference between the two groups in regard to respiratory medication use in the 12 months
prior to follow up, as measured using PBS and RPBS data.
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