Premium
The CARET asbestos‐exposed cohort: Baseline characteristics and comparison to other asbestos‐exposed cohorts
Author(s) -
Barnhart Scott,
Keogh James,
Cullen Mark R.,
Brodkin Carl,
Liu Diane,
Goodman Gary,
Valanis Barbara,
Glass Andrew,
Thornquist Mark,
Rosenstock Linda,
Omenn Gilbert,
Balmes John
Publication year - 1997
Publication title -
american journal of industrial medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.7
H-Index - 104
eISSN - 1097-0274
pISSN - 0271-3586
DOI - 10.1002/(sici)1097-0274(199712)32:6<573::aid-ajim1>3.0.co;2-r
Subject(s) - medicine , asbestos , cohort , cohort study , mesothelioma , surgery , pathology , materials science , metallurgy
The Carotene and Retinol Efficacy Trial (CARET) was a double‐blind, placebo‐controlled trial of the daily administration of 25,000 IU vitamin A and 30 mg β‐carotene for the prevention of lung cancer. Of close to 18,500 participants, more than 4,000 were asbestos‐exposed men recruited from shipyard and construction trades at five study centers in the United States. While the primary endpoint of the trial was the incidence of lung cancer, a number of questions about the natural history of asbestos‐related disease will also be addressed. The mean age at entry into the trial was 57 years and the mean duration of follow‐up on active intervention was 4 years. With the exception of 133 never‐smoker pilot participants (3%), all subjects recruited were by intention current (38%) or ex‐smokers (58%), with a mean cumulative smoking exposure at entry of 43 pack‐years. Mean years from first asbestos exposure were 35, and mean duration of asbestos exposure in a high‐risk trade was 19 years. The distribution of radiographic abnormalities was as follows: normal, 34%; parenchymal opacities (ILO profusion score >1/0) alone, 18%; pleural thickening alone, 27%; both parenchymal opacities and pleural thickening, 21%. The CARET cohort, when compared to previously reported asbestos‐exposed cohorts, is characterized by substantial asbestos exposure and high proportion of asbestos‐related radiographic findings. The active intervention was halted in 1996, after a mean duration of 40 years. Passive follow‐up of the cohort will continue until the year 2000. Am. J. Ind. Med. 32:573‐581, 1997. © 1997 Wiley‐Liss, Inc.