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.