Data Collection and Management
The information collected over a three year period included a battery of detailed physiologic
and performance measurements and questionnaire material regarding demographic
characteristics, multiple aspects of health status, and medication use. For medications at year
3, participants were asked to bring to clinic all prescription and over the counter medications
they had taken in the previous two weeks. Well trained examiners transcribed from the
medication containers information on medication name, dosage form, and whether the
medication was taken as needed.. The medication data was coded using the Iowa Drug
Information System (IDIS) codes and then entered into a computerized database.14