Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT00032461 |
| Other study ID # |
458 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
N/A
|
| First received |
March 20, 2002 |
| Last updated |
January 20, 2009 |
| Start date |
November 1998 |
| Est. completion date |
April 2001 |
Study information
| Verified date |
March 2007 |
| Source |
VA Office of Research and Development |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
United States: Federal Government |
| Study type |
Observational
|
Clinical Trial Summary
Primary Hypothesis: Gulf War veterans will have an equal prevalence or mean level of the
following medical and psychological conditions frequently reported in the literature
compared to a control group of nondeployed veterans: (1) chronic fatigue syndrome, (2)
fibromyalgia, (3) post-traumatic stress disorder, (4) neurologic abnormalities, including
peripheral neuropathy and cognitive dysfunction, and (5) general health status.
Description:
* 1,000 Gulf War veterans, spouses, & children and 1,000 non-deployed Gulf War era veterans,
spouses, & children.
Primary Hypothesis: Gulf War veterans will have an equal prevalence or mean level of the
following medical and psychological conditions frequently reported in the literature
compared to a control group of nondeployed veterans: (1) chronic fatigue syndrome, (2)
fibromyalgia, (3) post-traumatic stress disorder, (4) neurologic abnormalities, including
peripheral neuropathy and cognitive dysfunction, and (5) general health status.
Secondary Hypotheses: (1) Medical conditions that were reported as more frequent among Gulf
War veterans compared to nondeployed veterans in the self-reported data in Phase I will be
of equal prevalence in the two groups upon objective clinical examination. These include
arthritis, dermatitis, hypertension, bronchitis, and asthma. (2) The prevalence of the above
medical conditions in the primary hypotheses and secondary hypothesis (#1) will be equal
between the spouses of Gulf War veterans and those of nondeployed veterans. (3) The
prevalence of major birth defects found on a pediatric physical examination of veterans'
biologic children conceived after the war to Gulf War veterans and nondeployed veterans will
be equal; the prevalence of medical conditions in children living in the veterans'
household, whether conceived before or after the war, for Gulf War veterans and nondeployed
veteran will be equal.
Intervention: This is an observational study.
Primary outcomes variables: chronic fatigue syndrome; post-traumatic stress disorder,
fibromyalgia; peripheral neuropathy; cognitive dysfunction; and general health status:
physical component and mental component.
Study Abstract: In response to a legislative mandate, the VA initiated a survey entitled A
National Health Survey of Persian Gulf Veterans and Their Families. The survey was designed
as a retrospective cohort study in which the health of a population-based sample of 15,000
troops deployed into the Persian Gulf area was compared to those of 15,000 troops not
deployed in the Persian Gulf area. The survey was to be conducted in three phases. In Phase
I of the study, a structured health questionnaire was mailed to each of the 30,000 Persian
Gulf War-era veterans who were sampled for the survey. Up to four follow-up mailings were
sent to non-respondents to increase the response rate in a six-month period. In Phase II,
telephone interviews of a sample of 8,000 non-respondents and a review of selected medical
records for a sample of 4,000 veteran respondents were conducted. Through additional
telephone interviews with non-respondents, the potential for non-participant bias was
evaluated. The medical records review helped in assessing validity of selected self-reported
health data (clinic visit, hospitalization, pregnancy outcomes, birth defects among
children, infant deaths, etc.).
The present protocol represents Phase III of the study--clinical examinations of a sample of
1,000 Gulf War (GW) veterans and their spouses and children and 1,000 Gulf War era
nondeployed veterans and their spouses and children. Results from Phase I indicated that the
prevalence of several self-reported health conditions are elevated in the GW veterans
compared to the control group. The overall purpose of the Phase III study is to corroborate
these findings through more objective clinical examination.
A sample from a pool of Phase I and Phase II Persian Gulf War veterans and Persian Gulf era
nondeployed veterans were generated. Dr. Kang's office provided the 16 participating medical
centers with names and phone numbers of veterans to be contacted. Each medical center
examined an average of 125 veterans, 95 spouses, and 123 children over a period of 30
months. The VA medical centers were strategically selected so that there was a VA medical
center within driving distance of the majority of the families sampled. Veterans were
contacted first by letter and then by telephone through the site closest to their home and
invited to participate in the study. Exams were scheduled for the veteran and
spouse/children if they were participating. Data from these exams were sent to the Hines
CSPCC for cleaning and analysis. Travel arrangements and expenses were provided for the
participants and they were reimbursed for their time.
Characteristics of Participants: Mean age for deployed veterans who were examined was 38.9
yrs. compared with 40.7 yrs. for non-deployed veterans who were examined (p<.0001). Mean
income was $46,800 for deployed and $52,000 for non-deployed participants (p=.003).
Non-deployed participants were more likely to be white (81.0% vs. 76.4%, p=.03), to be
married (72.3% vs. 67.4%, p=.02), and to continue education past high school (42% vs. 32.5%,
p<.0001). Results for Veterans: Both the physical and mental component scores derived from
the SF-36 were significantly lower among deployed veterans who were examined. For the
physical component score, the mean for the deployed group was 48.2 (s.d. 9.8) compared with
50.8 (s.d. 8.3) for the non-deployed group, p<.0001. The mental component score averaged
49.6 (s.d. 10.2) for the deployed group and 53.7 (s.d. 7.9) for the non-deployed group,
p<.0001. There was a weak trend for a higher prevalence of fibromyalgia in the deployed
group (3.1%) than in the non-deployed group (1.9%), [odds ratio 1.64, 95% confidence
interval (.94, 2.87), p=.09]. There was a higher prevalence of chronic fatigue syndrome
among deployed (1.6%) than non-deployed (0.4%), [odds ratio 4.58, 95% confidence interval
(1.53, 13.64), p=.003]. Among the seven cognitive dysfunction factors, there was a trend
towards a higher prevalence of impaired attention/working memory among deployed (6.6%) than
non-deployed (4.2%), [odds ratio 1.60, 95% confidence interval (1.10, 2.35), p=.02]. PTSD
after the Gulf War was more prevalent among deployed (10.1%) than non-deployed participants
(3.2%), [odds ratio 3.41, 95% confidence interval (2.30, 5.05), p<.0001]. No differences
were found for peripheral neuropathy and 6 of the 7 factors defined to assess cognitive
dysfunction. Among secondary outcome measures, several categories of skin conditions were
found to be more prevalent among deployed veterans. Results for Spouses: The mean score for
the mental component scale was lower in the spouses of deployed participants (50.3 (s.d.
9.9)) than in the spouses of non-deployed participants (52.6 (s.d. 8.6), p<.0001). No other
outcome measures for spouses were found to be related to deployment status of the veteran.
Birth Defects: No statistically significant relationship between deployment status and
prevalence of birth defects among first live born offspring born after the Gulf War was
found. Summary: Although participation rates were lower than anticipated, we found little
evidence of participation bias. Veterans deployed to the Gulf War have higher rates of
chronic fatigue syndrome and post-Gulf War onset PTSD, and poorer health-related quality of
life. Attention/working memory deficits and fibromyalgia may also be related to deployment
to the Gulf War. Additional Comments: Additional analytic work remains: (a) the results have
not been adjusted for covariates such as age, (b) certain subgroups were oversampled and the
results are not adjusted for the study's original sampling methodology, (c) analysis of
subgroups that are purported to be at increased risk of health impacts due to their type of
service in the Gulf War has not been done.
