In three generations of families participating in FHS, data from the most recent examination were analyzed. Eligible examinations providing spirometry and questionnaire data included examinations 13, 16, 17, and 19 in the original cohort (in approximate two-year intervals); examinations three, five, six, and seven in the offspring generation (in approximate four-year intervals); and the one examination completed to date for the third generation. Equipment used in the standard protocol evolved as technology improved over the decades of study62. A Collins Survey water-filled spirometer (Collins Medical, Inc.) was used for most examinations, with measurements made by Eagle II microprocessor (Collins Medical, Inc.) or by software from the S&M Instruments. In more recent examinations, a Collins Comprehensive Pulmonary Laboratory dry rolling-seal spirometer and Collins 2000 Plus/SQL Software (Collins Medical, Inc.) were used.
