Medical Requirements Integration Documents (MRID) / Medical Evaluation Documents, Volume B (MEDB) Medical data is collected for clinical purposes, and requirements are periodically reviewed and updated according to medical need. The initial medical requirements were developed in the MRID documents. More recently, some of the MRIDs have been updated by newer requirements called MEDBs. These requirements may list both MRID and MEDB numbers as a result, and the data available for these tests may vary based upon the implementation dates of the specific MRID and MEDB requirements.

LSAH Annual Preventive Examinations: Active and retired astronauts receive an annual preventive medical examination as part of the LSAH occupational surveillance program. Much of the data collected as part of this annual examination is listed under “Therapeutics and Clinical Care” as MR089S. Other tests may be added to the annual exam based on an individual’s family or personal medical history and based upon updates to the United States Preventive Services Task Force national guidelines.

Other Clinical Data: As the new LSAH occupational surveillance program develops individual hazard exposure profiles and monitoring protocols, some of this data may become available once an adequate dataset is available to protect astronaut confidentiality. Check back over the next 1-2 years for information related to occupational surveillance data.

In addition, medical requirements have evolved throughout the human spaceflight program. Therefore data collected under an early medical requirement may not be consistent for all flights over time, and the specific data collected may vary. For example, medical requirements documented in the MRID documents may have been updated by newer requirements called MEDBs.

Annual preventive medical exam data is typically collected during each astronaut’s birth month, but may be inconsistent based upon schedule conflicts or, for retired astronauts, travel issues. Individual participation in the LSAH annual exams is optional after retirement from the astronaut corps, therefore the number of available data sets and even content of the exams may vary from year to year.

Specifically, the primary a priori hypotheses to be tested were: 1) astronauts are at different risk of total morbidity (defined as rate of incident cases of diseases/disorders, rate of hospitalizations, and average number of hospitalization days per person), than ground-based employees; and 2) astronauts are at different risk of total mortality than ground-based employees. All astronauts selected for the NASA astronaut program were followed as "exposed" subjects from selection through-out the course of the study.

The Longitudinal Study of Astronaut Health (LSAH) was a designed as a cohort study, and risk was measured relative to civil service employees located at the Johnson Space Center (JSC) who worked and lived, at least for a time, in the same geographical area as the astronauts. All cohorts volunteered to participate in the study. Civil service employees who received routine annual physical examinations at the JSC Occupational Medicine Clinic were selected as comparison subjects using age, sex, and body mass index as selection criteria, and they were followed in the same manner as the astronauts. As new astronauts were selected, matching groups of comparison participants were identified and recruited. The ratio of participants was three comparison subjects for every one astronaut, later changed to a ratio of 5:1. Morbidity, mortality, physical examination, and laboratory data were collected utilizing medical records routinely collected at the Johnson Space Center, as well as medical consultant reports, hospital discharge summaries, death certificates, and, when available, autopsy reports.

Analyses on the LSAH data continue to be performed though the research study was closed and comparison subjects were released in May 2010. The LSAH databases are useful as computerized medical records as well as for research purposes. The personal medical data included in the data bases of the LSAH are protected by the Privacy Act of 1974, as amended, by the HIPAA (Health Insurance Portability and Accountability Act (HIPAA) of 1996 (Public Law 104-191)), and by the additional security procedures and policies of NASA, the LSAH and the JSC Clinics. Individual participant data are not included in reports or publications; only grouped data are presented.