The Vietnam Era Health Retrospective Observational Study (VE-HEROeS) is a national study on the health and well-being of Vietnam Veterans, including Blue Water Navy Veterans, as well as Veterans who served elsewhere during the Vietnam Era (1961-1975), and similarly aged U.S. residents who never served in the military. The investigators will invite approximately 43,000 Vietnam and Vietnam Era Veterans, and approximately 11,000 members of the general U.S. population to participate in VE-HEROeS. These individuals are scientifically selected to participate; the study is not able to accept volunteers.

All participants in VE-HEROeS will be asked to fill out a questionnaire on their military service, general health, age-related conditions, health care use, and the health experiences of their children and grandchildren. A smaller group will be asked to provide the investigators with access to some of their medical records. Topics of special focus for the study include cognition, hepatitis C infection, and neurologic conditions.

It has been more than 40 years since the Vietnam War ended and there is little recent systematic knowledge of how Veterans of the Vietnam Era (1961-1975) have fared with regard to their overall health, lifestyle factors, and aging. This epidemiologic study, called the Vietnam Era Health Retrospective Observational Study (VE-HEROeS) will provide information about the health and well-being of Veterans of the Vietnam Era to Veterans and their families who have questions about the long-term health effects of service during the Vietnam War, to clinicians who care for Veterans and lack sufficient evidence to explain health conditions, and to the VA healthcare system in order to improve VA healthcare and anticipate future healthcare needs. The main objective of this study is to determine if the overall health of Veterans of the Vietnam War and Vietnam Era, with a special focus on neurologic conditions and hepatitis C infection, is different from that of their counterparts who did not serve in the military. Exploratory aims of the study are to determine if the investigators can obtain a sample of Blue Water Navy Vietnam Veterans (who served exclusively in deep coastal waters off of North or South Vietnam) and use the survey to describe their current health, and to determine the prevalence of Veterans who attribute health conditions of their descendants to their own military service, especially conditions potentially transmitted epigenetically. The study design is a survey, with hepatitis C and neurologic conditions validated by medical record review. The questionnaire includes both validated scales and new items about physical and mental health, exposures, and lifestyle. There are two versions of the questionnaire: one for Veterans of the Vietnam Era and one for those selected from the U.S. general population who have never served in the military. The questionnaires are as similar as possible, with the exception of questions about military service, exposures, or experiences that are either removed or modified in the non-Veteran questionnaire because they do not apply to this population.

Inclusion Criteria:

• invited to participate through investigators' random sample selection process
• able to provide informed consent
• have a postal address in the U.S. or its territories

Exclusion Criteria:

• individuals who are incarcerated
• individuals who are unable to complete the survey even with assistance because of cognitive or physical limitations.

Veterans: We will obtain a stratified random sample of 45,067 Veterans from the Department of Veterans Affairs' United States Veterans Eligibility Trends & Statistics (USVETS) database which we believe to be the most complete database of U.S. military Veterans in existence. Stratification will be on period of service within the Vietnam era: 1961-1964 or 1965-1975. We will remove decedents and those without a current US postal address from the sample.

U.S. public: The U.S. public general population comparison sample will be an age- and gender-matched sample of living non-Veteran members of the U.S. public born before 1958.

Aggregate data will be available to investigators in accordance with VA access policy.