Radiographic features of importance in the National Institute for Occupational Safety and Health-administered Coal Workers’ Health Surveillance Program: characterising the use of the ‘other symbols’

Abstract

ObjectiveThe National Institute for Occupation Safety and Health-administered Coal Workers’ Health Surveillance Program (CWHSP) provides radiographic pneumoconiosis screening for US coal miners. Radiographs are classified by readers according to International Labour Office criteria. In addition to pneumoconiotic parenchymal and pleural lung abnormalities, readers document radiographic features of importance (other symbols). Other symbols are not meant to imply a diagnosis or interpretation but are relevant as they provide information beyond a pneumoconiosis classification for features related to dust exposure and other aetiologies. Our objective was to summarise other symbol data from 48 years of CWHSP participants.MethodsChest radiograph classifications obtained from CWHSP participants between July 1968 and July 2016 were analysed. Any ‘other symbol’ indication from any of the readings were counted. Frequencies were tabulated by individual reader and those identified by any reader.ResultsOf the 469 922 radiographs included in this study, nearly 15% had at least one reader identify a radiographic feature of importance. The most commonly identified other symbol was cancer (excluding mesothelioma) (6.83%), followed by emphysema (1.68%). Some features were rarely identified over the 48 years of data collection such as rheumatoid pneumoconiosis (n=46), pneumothorax (n=32), mesothelioma (n=12) and rounded atelectasis (n=4).ConclusionsThis is the largest study to date describing radiographic features of importance as part of routine chest radiographic surveillance. While these symbols are not diagnostic they can be used to describe features associated with dust exposure. One of the most commonly identified radiographic features in our population is emphysema which is associated with respirable dust exposure. These results can be compared with other dust exposed populations.

The National Institute for Occupational Safety and Health B Reader Certification Program—An Update Report (1987 to 2018) and Future Directions

“…In general, readers with less training tended to identify more pneumoconiosis than experienced readers, 5 a trend that has been observed across several dust exposed worker populations in multiple countries over the last three decades. 10,[18][19][20][21][22] This finding is consistent with the high rate of false positives among examinees who fail the examination observed in the present study (Fig. 5).…”

“…Thus, it was critical for the CWHSP to enable the use of digital chest radiographic images for ILO classification. To facilitate this, NIOSH (i) conducted research studies demonstrating that digital chest radiographs acquired on systems widely used in clinical practice could provide similar results to traditional film-screen radiographs when used for classification of pneumoconioses using the ILO system [8][9][10][11][12] ; (ii) provided detailed guidance on appropriate methods for image acquisition and viewing when using digital technology for ILO classification 13 ; and (iii) developed the BViewer© Software (a freeware computer program that enables standardized viewing of digitally-acquired chest images for classification purposes, alongside digital versions of the ILO standards, and includes software for electronically recording classification results). 14 With this foundation in place, NIOSH worked with the ILO in updating its classification system to enable use of digital chest radiographs 2 and amended NIOSH regulations to enable use of digital chest radiography in addition to traditional film radiographs in the CWHSP.…”

The B Reader Program, Silicosis, and Physician Workload Management

“…11 As its name implies, ''B'' Readers were initially called upon to confirm suspected features of pneumoconiosis in a second-opinion capacity. 12 The program today dispenses with the preceding ''A'' Readers and instead relies upon a cadre of highly trained B Readers to independently establish findings of CWP. 13 Since 1976, the program has sought to minimize interobserver variability through a rigorous certification process, evaluating candidates on the basis of their ability to categorize images according to the International Labour Organization (ILO) International Classification of Radiographs of Pneumoconioses.…”

“…The NIOSH B Reader system finds its origins in this program, which aimed to identify, certify, and engage qualified physicians in a national CWP screening endeavor 11 . As its name implies, “B” Readers were initially called upon to confirm suspected features of pneumoconiosis in a second-opinion capacity 12 . The program today dispenses with the preceding “A” Readers and instead relies upon a cadre of highly trained B Readers to independently establish findings of CWP 13 .…”

Effects of occupational exposure to dust on chest radiograph, pulmonary function, blood pressure and electrocardiogram among coal miners in an eastern province, China

“…Owing to its progression and irreversibility, no specific medicine and effective treatment are suitable for CWP. So the patients always lose labor ability, reduce life quality and shorten life expectancy [6, 7].…”