Transitioning from a Longitudinal Study to an Occupational Surveillance Program: The Lifetime Surveillance of Astronaut Health (LSAH)

Astronauts represent a ‘healthy worker' population with unique occupational exposures not normally encountered by the general public. Stringent selection standards and medical care required for space mission success result in the tendency of astronauts to be healthier than the general population and different in terms of demographic and physiologic characteristics.During the 1980's, interest in studying spaceflight human health and performance increased as missions on the new Space Shuttle lengthened from a few days to over 10 days. From 1989-2010, NASA implemented the Longitudinal Study of Astronaut Health (LSAH) to investigate the incidence of acute and chronic morbidity and mortality in astronauts and to determine whether their occupational exposures were associated with increased risk of death or disability. Astronaut participants were matched against a comparison group of NASA civil servants at either a 1:5 (1989-1991) or a 1:3 ratio (1992-2010) using age, gender, and Body Mass Index (BMI) as key parameters. By 2003-4, the typical spaceflight mission had lengthened to 6 months, and NASA asked the U.S. Institute of Medicine (IOM) to review the LSAH. The IOM panel recommended transforming the research study into an occupational surveillance program to more effectively monitor astronaut health and understand the risks associated with long duration spaceflight missions.In 2010, NASA initiated the new Lifetime Surveillance of Astronaut Health (also LSAH) project. This discussion addresses the challenges and benefits of transitioning to an occupational surveillance program for workers with a wide variety of unique exposures, the long-term effects of which are still under investigation.