Who can participate?
The BLSA has a rigorous screening process for potential participants. A person must meet the following criteria to be eligible for the BLSA:
- Age 20 years or older
- No difficulties or need for help in performing self-care or instrumental activities of daily living
- Able to walk independently for at least 400 meters without using assistive devices
- No shortness of breath while performing normal activities of daily living, such as walking or climbing stairs
- No substantial cognitive impairment based on mental status screening tests
- No evidence of compromised immune function
- Weigh less than 300 pounds and/or have a BMI of less than 40 kg/m2
- In good health at time of enrollment (with no history of cardiovascular disease, diabetes, active cancer, metabolic disease, severe hormonal dysfunction, neurological diseases, established genetic diseases, birth defects, kidney or liver disease, severe gastrointestinal disease, muscle-skeletal conditions due to disease or trauma, severe psychiatric conditions, any medical condition that requires continuous use for long term treatment with antibiotics, corticosteroids, immunosuppressants, H2 blockers or pain medications, severe sensory deficits [e.g. legally blind] and/or any condition that precludes neuropsychological testing or providing informed consent)
If conditions considered as exclusion criteria for study entry develop any time after the baseline evaluation, the participant remains in the study.
How frequent are study visits?
Potential participants must agree to make every effort to be followed through their lifetime, coming to the BLSA study site in Baltimore, Maryland. Study visits are scheduled at several-year intervals, depending on the age of the participant.
The BLSA uses the following schedule:
- 20 to 59 years—approximately every 4 years
- 60 to 80 years—approximately every 2 years
- Older than 80 years—approximately every year
If a BLSA participant is unable to attend their study visit, follow-up information may be collected through a home visit or telephone interview.