Changes in B-readings over time in the United States Navy Asbestos Medical Surveillance Program
John G Muller1, W Garry Rudolph, Jonathan M Lieske
1Navy Environmental Health Center, Military Sealift Fleet Support Command, Norfolk, VA 23708-2103, USA. mullerj@nehc.med.navy.mil
Objective:
To study the impact of variability among B-readers on clinical occupational medicine.
Methods:
A total of 419,770 B-reading reports from February 1980 to May 2004 in the US Navy Asbestos Medical Surveillance Program were analyzed for changes in category from the previous B-reading on each individual worker.
Results:
Over 7% of films were categorized as worse (ie, read as going from negative to positive), and over 6% were categorized as better. When profusion categories were reported as different from the previous reading (over 6% of the time), they were more frequently read as 2 or more minor categories worse or better.
Conclusions:
Changes from previous B-readings are common, and may have clinical and other implications, which are discussed. B-readings should not be used as the sole basis for determining the presence or absence of pneumoconiosis.
