Health and exposures of United Kingdom Gulf war veterans. Part II: The relation of health to exposure

Objectives-To investigate whether, in personnel who served with the United Kingdom forces in the Gulf war, self reported exposures were related to symptoms in a way that was consistent, specific, and credible. Methods-Responses to symptom and exposure questionnaires, completed 7 or more years after the war, were collected from 7971 subjects deployed in the Gulf, from two exposed cohorts, in a study with an overall response rate of 85.5%. Exposures were considered in three groups, those outside the control of the subjects, the use of prophylaxis, and indicators of susceptibility. Health indices derived from symptom questionnaires were related to reports of 14 exposures in these three groups in a series of multiple regression analyses to allow for confounding. The relation of exposure to complaints of widespread pain and to symptoms suggesting peripheral neuropathy were examined by logistic regression. Results-Consistent but weak correlations between exposures and with health effects were found in independent analyses of the two (main and validation) cohorts. Three exposures outside the control of the subject, the number of inoculations, the number of days handling pesticides, and the days exposed to smoke from oil fires, were consistently and independently related to severity. The number of inoculations was also associated with higher scores on a factor weighted on symptoms associated with skin and musculoskeletal complaints. The number of days handling pesticides related particularly to scores on a neurological factor and to symptoms consistent with toxic neuropathy. Conclusion-The relations between exposures and ill health were generally weak. Consistent, specific, and credible relations, warranting further investigation, were found between health indices and two exposures, the reported number of inoculations and days handling pesticides.