Cohort Profile: NASA Astronauts as an Occupational Cohort

Purpose
Occupational cohorts are important to understanding the unique exposures of a workforce. The crewmembers selected by NASA to be astronauts experience occupational exposures unlike any other. To better understand the short- and long-term health effects of spaceflight, health and exposure data is collected on this cohort through clinical and other surveillance settings.

Participants
This cohort is comprised of the 360 astronauts who have been selected by NASA from the first selection class in 1959 to the most recent class of 2022. Selection of crew members is based on specific skills, education, military experience, and fitness for flight. Due to the stringent and specific selection criteria, this occupational cohort encompasses a population that are more homogenous than other groups. However, with the evolution of selection criteria along with changes to health screening and data collection processes, each selection class has varying baseline health status.

Findings to Date
Data on a variety of health outcomes and risk factors have been collected in concert with occupationally derived human physiologic and exposure data, demographic and socioeconomic information, and exposures that occurred prior to selection. Data have been utilized for both research activities, such as studies addressing Spaceflight Associated Neuro-ocular Syndrome (SANS) and venous thromboembolism, and occupational surveillance activities like monitoring cardiovascular health pre-, in, and post- flight. Characterization of these factors helps not only with current monitoring but also informs future risk reduction decisions for exploration missions.

Future Plans
As NASA plans missions to the Moon and Mars, the evidence base for this cohort will continue to grow through monitoring of current, future, and retired crewmembers. As more data is collected, future research and surveillance activities will continue to be developed both internally and externally.

Strengths and Limitations
Strengths:
- Cohort is closely followed over course of lifetime starting with a rigorous selection exam
- Large amount of data collected for each individual crewmember
- Minimal risk of loss to follow up due to medical monitoring requirements

Limitations:
- Small sample sizes limit ability to address specific
- High health and fitness standards upon selection and resources provided by employment