Changes in B-readings over time in the United States Navy Asbestos Medical Surveillance Program

Our plain-English summary of Changes in B-readings over time in the United States Navy Asbestos Medical Surveillance Program, by J.G. Muller, W.G. Rudolph, J.M. Lieske, et al (Journal of Occupational and Environmental Medicine, 2007).

The study

• Authors: J.G. Muller, W.G. Rudolph, J.M. Lieske, J.E. Hernandez, M.H. Jan, G. Kubiak
• Journal: Journal of Occupational and Environmental Medicine
• Published: 2007;49(2):194-203
• Cited by: 3 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

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.

In plain English

This study measured how often chest X-ray readings changed in the US Navy Asbestos Medical Surveillance Program. The authors analyzed 419,770 follow-up B-readings (standardized chest X-ray classifications by certified physicians) on 102,770 workers, from February 1980 to May 2004. They compared each reading with the same worker's previous reading. About 85% matched the previous reading as overall positive or negative for pneumoconiosis. In 7.87% the reading went from negative to positive, and in 6.58% from positive to negative. Among B-readers who read more than one follow-up film, the share of readings unchanged as overall positive or negative ranged from 71.77% to 92.74%. When profusion readings worsened, 4584 changed by 1 category and 6386 by 2. In 39 cases, large opacities of size B were later read as none. Readings were not checked against a gold standard or workers' histories. The authors concluded that most variation appeared to come from the readings themselves. They also concluded that B-readings should not be the sole basis for treatment or for establishing the presence or absence of occupational injury or illness.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Retrospective descriptive analysis of records in a medical surveillance database, comparing each worker's B-reading with that worker's previous B-reading
• Who was studied: 102,770 workers with more than one B-reading in the US Navy Asbestos Medical Surveillance Program. There were 522,540 records in all, of which 419,770 were follow-up (non-initial) readings, dated February 1980 to May 2004. The readings were made by 57 B-readers. The average time between a worker's first and last B-reading was 8.48 years.
• Exposure: Workers in the Navy's asbestos medical surveillance program, described as asbestos workers. Fiber types, jobs and doses were not analyzed. The study examined variability in ILO B-readings of posterior-anterior chest X-rays.
• Main results:
  • Across all follow-up readings, about 85% matched the previous reading for overall positive or negative. 7.87% went from negative to positive (worse), and 6.58% went from positive to negative (better).
  • Among B-readers who read more than one follow-up film, the percentage of readings unchanged from the previous reading (overall positive or negative) ranged from 71.77% to 92.74%. Two readers who each read a single follow-up film had 0% and 100% unchanged.
  • When profusion readings changed, they tended to change by 2 categories: 4584 readings were worse by 1 category and 6386 by 2 categories.
  • 39 large opacities of size B were later read as none.
  • There was no significant unweighted correlation between how many follow-up films a B-reader read and the percentage of unchanged readings. The weighted correlation was statistically significant but not strong (Pearson's R from 0.115 to 0.226 across the findings examined).
  • Across 5-year periods, the change in the likelihood of readings being the same or changed was statistically significant (chi-square for linear trend 9.397, 1 degree of freedom). However, the trend-line slopes were minimal.
• The authors' conclusion: The authors concluded that, while some worsening may be expected from disease, most variation appeared to be due to variation among the B-readings themselves. They concluded that B-readings should not be the sole basis for disease treatment or for establishing the presence or absence of occupational injury or illness.
• Limitations the authors state:
  • Readings were not correlated with workers' history and physical findings, such as smoking status, age, respiratory complaints or exposure.
  • The B-reader who did the previous or subsequent reading was not tracked, so agreement or disagreement between particular readers could not be assessed.
  • Changes in shape, size and location of parenchymal findings were not analyzed, nor were changes in the type, width, extent or calcification of pleural findings.
  • Consistency was measured rather than accuracy. Readings were not compared with any gold standard.
  • Initial films cannot be evaluated for change, so rates in the program's early years are less meaningful.
  • The excess of worse over better readings may reflect disease or some other factor.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Asbestosis, The Navy.

Medical terms in this study, explained in our Lexicon: B-Reader, Pneumoconiosis.

Related studies

• Variability in interpretation among B-readers in the U.S. Navy Asbestos Medical Surveillance Program — J.G. Muller, J.M. Lieske, et al. (2008)
• Navy Asbestos Medical Surveillance Program 1990-1999: demographic features and trends in abnormal radiographic findings — D.M. Dell, B.K. Bohnker, et al. (2006)
• Navy Asbestos Medical Surveillance Program (1984-1990): linear regression analysis for effect of asbestos exposure on pulmonary function testing — B.K. Bohnker, L.S. Betts, et al. (2004)
• Navy Asbestos Medical Surveillance Program (1991-1999): linear regression analysis for the effect of asbestos exposure on pulmonary function testing — B.K. Bohnker, L.S. Betts, et al. (2004)
• Trends in pleural radiographic findings in the Navy Asbestos Medical Surveillance Program (1990-1999) — J.G. Muller, B.K. Bohnker, et al. (2005)
• Programmed health surveillance and detection of emerging diseases in occupational health: contribution of the French national occupational disease surveillance and prevention network (RNV3P) — V. Bonneterre, L. Faisandier, et al. (2010)

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