The challenges of exposure assessment in health studies of Gulf War veterans

Abstract

A variety of exposures have been investigated in Gulf War veterans' health studies. These have most commonly been by self-report in a postal questionnaire but modelling and bio-monitoring have also been employed. Exposure assessment is difficult to do well in studies of any workplace environment. It is made more difficult in Gulf War studies where there are a number and variety of possible exposures, no agreed metrics for individual exposures and few contemporary records associating the exposure with an individual. In some studies, the exposure assessment was carried out some years after the war and in the context of media interest. Several studies have examined different ways to test the accuracy of exposure reporting in Gulf War cohorts. There is some evidence from Gulf War studies that self-reported exposures were subject to recall bias but it is difficult to assess the extent. Occupational exposure-assessment methodology can provide insights into the exposure-assessment process and how to do it well. This is discussed in the context of the Gulf War studies. Alternative exposure-assessment methodologies are presented, although these may not be suitable for widespread use in veteran studies. Due to the poor quality of and accessibility of objective military exposure records, self-assessed exposure questionnaires are likely to remain the main instrument for assessing the exposure for a large number of veterans. If this is to be the case, then validation methods with more objective methods need to be included in future study designs.

The Deployment Health Surveillance Program: vision and challenges of health surveillance for Australian military cohorts

“…Exposure assessments a challenge in military health research, 21 and most studies still rely heavily on self‐reported exposure data, which is of course subject to recall bias. Ability to accurately and objectively assess the exposure(s) of individuals or groups is a critical element of health surveillance, as it provides the opportunity to assess the level of exposure that results in ill‐health 22 .…”

Organizational Psychosocial Factors and Deployment-Related Exposure Concerns in Afghanistan/Iraq War Veterans

“…As such, self-report is frequently used as a surrogate for deployment-related exposures in the vast majority of research studies and clinical encounters. 9 There is no standardized validated questionnaire used to assess veterans' occupational and environmental exposures in theater. In line with occupational health studies and most Gulf War studies, exposures in this study were assessed using checklist questionnaires because studies demonstrate that qualitative rating of perceived exposures tends to correlate reasonably well with an external standard.…”

“…In line with occupational health studies and most Gulf War studies, exposures in this study were assessed using checklist questionnaires because studies demonstrate that qualitative rating of perceived exposures tends to correlate reasonably well with an external standard. 9,10 For the purposes of the WRIISC clinical evaluation, an exposure assessment questionnaire measure was created by one of the authors (R.T.), an occupational and environmental medicine physician who specializes in postdeployment environmental exposure concerns. Development of this questionnaire was based on clinical experience and questionnaires used in previous studies, 4,9,[11][12][13][14] and the questions were adapted to address specific exposures pertinent to deployment to Iraq/Afghanistan as well as the level of concern associated which each reported exposure.…”

“…These are the most common deployment-related exposures of interest that have been evaluated in studies of Gulf War veterans by other researchers. 4,9,[11][12][13][14] In addition to listing potential exposures, the WRIISC intake exposure questionnaire asked the veterans to indicate the level of concern they had regarding each of the exposures they reported. Veterans were asked to rate their level of concern on a five-point Likert scale (0 = not at all concerned, 1 = somewhat, 2 = moderately, 3 = very, 4 = extremely concerned).…”

Accelerometers: Assessing their potential for measuring personal flotation device use on commercial fishing vessels

“…One study examining the accuracy of reported work‐related injuries demonstrates that the integrity of self‐reported injury data decreases when recall is greater than 2 months . Other studies have identified similar issues with time‐dependent recall . Survey fatigue, identified as a lack of interest in survey participation has led to a general decline in response rates to survey‐based data collection efforts in public health research…”