Reliability and validity of chest radiograph surveillance programs

Pitfalls of using the ILO classification for silicosis compensation claims

BACKGROUND

The International Labour Organization (ILO) Classification of Radiographs of Pneumoconioses is used as the primary tool to determine compensation for pneumoconiosis in Turkey.

AIMS

We aimed to evaluate how the ILO classification applied, but obtaining chest radiographs in the workplace for screening until the completion of compensation claim files by the referral centres, based on the ILO reading.

METHODS

The study included 320 digital chest radiographs previously taken for screening from eight different ceramic factories and having finalised claim files by referral centres. We used an expert reference panel consisting of five ILO readers to re-evaluate all the radiographs independently using ILO standard films and reached a conclusion based on the agreement among at least three readers. The evaluation primarily included technical quality and silicosis diagnosis with an ILO 1/0 or above small profusion. The results were compared with previous findings.

RESULTS

Sixty-three (20%) chest radiographs were unacceptable for classification purposes according to the ILO technical quality grades. Among the remaining 257 chest radiographs, we diagnosed 103 with silicosis (40%), while the referral centres diagnosed 182 (71%). A discrepancy was found between our results and previous evaluations. We diagnosed silicosis in 50% and 17% of the previous silicosis and normal evaluations, respectively.

CONCLUSIONS

Our findings suggest that the use of the ILO classification for compensation claims may be problematic due to the way of its implementation in Turkey in addition to its subjectivity.

Association Between Financial Conflicts of Interest and ILO Classifications for Black Lung Disease

RATIONALE

The US Department of Labor administers the Federal Black Lung Program (FBLP), an administrative system charged with managing claims by coal miners for workers' compensation for totally disabling coal mine dust lung disease. Specific case reports have raised concern that financial conflicts of interest (COI) may systematically bias physicians when they are classifying chest x-rays (CXRs) for the absence, presence and severity of pneumoconiosis.

OBJECTIVE

To evaluate the direction and magnitude of association between financial COI of physicians participating in the FBLP and international standards for the classification of radiographs of pneumoconiosis.

METHODS

An epidemiologic assessment of black lung claims filed to the FBLP, 2000-2013, was conducted to determine physician classifications of radiographs. FBLP court decisions for years 2002-2019 (n=7,656) were used to evaluate financial COI of each physician. The main outcome measures used were classifications of radiographs for the absence of pneumoconiosis (small opacity classifications of 0/0 or 0/1), simple pneumoconiosis (small opacity classifications of 1/0 through 3/+) and Progressive Massive Fibrosis (PMF; large opacities with classifications of A, B or C).

RESULTS

Out of 63,780 radiograph classifications made by 264 physicians, 31.4% were read positive for simple pneumoconiosis and 3.6% were read as having progressive massive fibrosis (PMF). There were 52 physicians who classified CXRs as having no evidence of pneumoconiosis in 99%+ of their readings, and 18 physicians who classified CXRs as positive for simple pneumoconiosis in 99%+ of their readings. The adjusted odds of a negative classification of pneumoconiosis was 1.46 (CI95%: 1.44, 1.47) per 10% increase in the proportion of court records demonstrating that a physician was hired by the employer. Per 10% increase in court records indicating a physician was hired by the miner-claimant, the adjusted odds ratio for classifying simple pneumoconiosis was 1.51 (CI95%: 1.49, 1.52) and for finding PMF was 1.28 (CI95%: 1.26, 1.30).

CONCLUSIONS

There was a strong association between source of payment and radiograph classification suggesting the importance of eliminating financial COI in what should be an objective determination of eligibility for Black Lung workers' compensation benefits.

Screening mammography: test set data can reasonably describe actual clinical reporting

PURPOSE

To establish the extent to which test set reading can represent actual clinical reporting in screening mammography.

MATERIALS AND METHODS

Institutional ethics approval was granted, and informed consent was obtained from each participating screen reader. The need for informed consent with respect to the use of patient materials was waived. Two hundred mammographic examinations were selected from examinations reported by 10 individual expert screen readers, resulting in 10 reader-specific test sets. Data generated from actual clinical reports were compared with three test set conditions: clinical test set reading with prior images, laboratory test set reading with prior images, and laboratory test set reading without prior images. A further set of five expert screen readers was asked to interpret a common set of images in two identical test set conditions to establish a baseline for intraobserver variability. Confidence scores (from 1 to 4) were assigned to the respective decisions made by readers. Region-of-interest (ROI) figures of merit (FOMs) and side-specific sensitivity and specificity were described for the actual clinical reporting of each reader-specific test set and were compared with those for the three test set conditions. Agreement between pairs of readings was performed by using the Kendall coefficient of concordance.

RESULTS

Moderate or acceptable levels of agreement were evident (W = 0.69-0.73, P < .01) when describing group performance between actual clinical reporting and test set conditions that were reasonably close to the established baseline (W = 0.77, P < .01) and were lowest when prior images were excluded. Higher median values for ROI FOMs were demonstrated for the test set conditions than for the actual clinical reporting values; this was possibly linked to changes in sensitivity.

CONCLUSION

Reasonable levels of agreement between actual clinical reporting and test set conditions can be achieved, although inflated sensitivity may be evident with test set conditions.

Comparing film and digital radiographs for reliability of pneumoconiosis classifications: a modeling approach

RATIONALE AND OBJECTIVES

The International Labour Office (ILO) system for classifying chest radiographic changes related to inhalation of pathogenic dusts is predicated on film-screen radiography. Digital radiography has replaced film in many centers. Digital images can be printed on film ("hard copy") or can be viewed at a computer workstation ("soft copy"). The goal of the present investigation was to compare the inter-reader and intra-reader agreement of ILO classifications for pneumoconiosis across image formats.

MATERIALS AND METHODS

Traditional film radiographs, hard copy digital images, and soft copy digital images from 107 subjects were read by six B readers. A multiple reader version of the inter-reader kappa statistic was compared across image formats. Intra-reader kappa comparisons were carried out using an iterative least-squares approach (unadjusted analysis) as well as a two-stage regression model adjusting for readers and subject-level covariates.

RESULTS

There were few significant differences in the inter-reader and intra-reader agreement across formats. For parenchymal abnormalities, inter-reader and intra-reader kappa values ranged from 0.536 to 0.646, and 0.65 to 0.77, respectively. In the covariate-adjusted analysis film-screen radiography was generally associated with a numerically greater reliability (ie, higher kappa values) than the other image formats, although differences were rarely statistically significant.

CONCLUSION

Film-screen radiographs, hard copy digital images, and soft copy digital images yielded similar reliability measures. These findings provide further support to the recommendation that soft copy digital images can be used for the recognition and classification of dust-related parenchymal abnormalities using the ILO system.

Outcomes of Tube Thoracostomies Performed by Advanced Practice Providers vs Trauma Surgeons

Background The role of advanced registered nurse practitioners and physician assistants in emergency departments, trauma centers, and critical care is becoming more widely accepted. These personnel, collectively known as advanced practice providers, expand physicians’ capabilities and are being increasingly recruited to provide care and perform invasive procedures that were previously performed exclusively by physicians.

Objectives To determine whether the quality of tube thoracostomies performed by advanced practice providers is comparable to that performed by trauma surgeons and to ascertain whether the complication rates attributable to tube thoracostomies differ on the basis of who performed the procedure.

Methods Retrospective blinded reviews of patients’ charts and radiographs were conducted to determine differences in quality indicators, complications, and outcomes of tube thoracostomies by practitioner type: trauma surgeons vs advanced practice providers.

Results Differences between practitioner type in insertion complications, complications requiring additional interventions, hospital length of stay, and morbidity were not significant. The only significant difference was a complication related to placement of the tube: when the tube extended caudad, toward the feet, from the insertion site. Interrater reliability ranged from good to very good.

Conclusions Use of advanced practice providers provides consistent and quality tube thoracostomies. Employment of these practitioners may be a safe and reasonable solution for staffing trauma centers.

Low-level fiber-induced radiographic changes caused by Libby vermiculite: a 25-year follow-up study

RATIONALE

From 1921 to 1990, vermiculite ore from Libby, Montana, was shipped worldwide for commercial and residential use. A 1980 study of a manufacturing facility using Libby vermiculite was the first to demonstrate a small but significant prevalence of pleural chest radiographic changes associated with amphibole fibers contained in the ore.

OBJECTIVES

This follow-up study of the original cohort evaluated the extent of radiographic changes and cumulative fiber exposure (CFE) 25 years after cessation of exposure.

METHODS

From the original cohort of 513 workers, 431 (84%) were living and available for participation and exposure reconstruction. Of these, 280 (65%) completed both chest radiographs and interviews. Primary outcomes were pleural and/or interstitial changes.

MEASUREMENTS AND MAIN RESULTS

Pleural and interstitial changes were demonstrated in 80 (28.7%) and 8 (2.9%) participants, respectively. Of those participants with low lifetime CFE of less than 2.21 fiber/cc-years, 42 (20%) had pleural changes. A significant (P < 0.001) exposure-response relationship of pleural changes with CFE was demonstrated, ranging from 7.1 to 54.3% from the lowest to highest exposure quartile. Removal of individuals with commercial asbestos exposure did not alter this trend.

CONCLUSIONS

This study indicates that exposure within an industrial process to Libby vermiculite ore is associated with pleural thickening at low lifetime CFE levels. The propensity of the Libby amphibole fibers to dramatically increase the prevalence of pleural changes 25 years after cessation of exposure at low CFE levels is a concern in view of the wide national distribution of this ore for commercial and residential use.

Enhanced myofibroblastic differentiation and survival in Thy-1(-) lung fibroblasts

Thy-1 is a glycosylphosphatidyl-inositol-linked cell surface glycoprotein whose exact biological role remains unclear. Differential expression of Thy-1 affects fibroblast proliferation and fibrogenic signaling. In idiopathic pulmonary fibrosis, the proliferating myofibroblasts within the fibroblastic foci are Thy-1(-), whereas normal lung fibroblasts are predominantly Thy-1(+). In this study, we used rat lung fibroblasts sorted for Thy-1 expression to examine myofibroblastic differentiation in response to fibrogenic stimuli. We examined the effects of transforming growth factor-beta, endothelin-1, and connective tissue growth factor on the expression of myofibroblast proteins and myogenic regulatory factors by real-time RT-PCR and immunoblotting. Thy-1(-) cells have significantly higher myofibroblast and myogenic regulatory factor gene and protein expression compared with Thy-1(+) cells, confirmed by immunofluorescence. We also used floating collagen matrix contraction assays to assess the functional differentiation of the fibroblasts. At baseline and after stimulation with transforming growth factor-beta and endothelin-1, Thy-1(-) cells caused significantly greater collagen contraction than did Thy-1(+) cells, supporting the hypothesis that Thy-1(-) cells are more fully differentiated myofibroblasts. Because apoptosis has been implicated in the regression of myofibroblasts, we examined the percentage of apoptotic cells in the contracted collagen matrices at baseline and after stimulation with fibrogenic agents. A significantly greater proportion of Thy-1(+) cells underwent apoptosis in all conditions compared with Thy-1(-) fibroblasts. Transfection of Thy-1 into Thy-1(-) cells inhibits collagen matrix contraction and reduces cell survival. Our data indicate that Thy-1 regulates myogenic gene expression, myofibroblastic differentiation, and survival in lung fibroblasts.

[Diagnosis and management of pleural effusions in critically iII patients]

INTRODUCTION

Pleural effusions are common in ICU patients. Causes include massive fluid resuscitation in shock, pneumonia--either community acquired or nosocomial, cardiac insufficiency, hypoalbuminemia and hepatic impairment. Pleural effusions frequently complicate cardiac and abdominal surgery and haemothorax may complicate trauma.

STATE OF THE ART

The incidence of pleural effusions in the intensive care unit (ICU) varies depending on the screening method used, from about 8% for physical examination to more than 60% for routine ultrasonography. In the absence of clinical parameters to exclude infection pleurocentesis remains an essential aspect of management and is not contraindicated mechanical ventilation. This review of the diagnosis and management of pleural effusions in ICU patients reports the most recent data from the literature. Pleurocentesis can be performed safely in the ICU, even in mechanically ventilated patients. The absence of reliable clinical or laboratory test criteria for determining the cause of pleural effusions and the potentially devastating consequences of failing to diagnose and treat pleural infection are strong reasons to perform pleurocentesis in patients with clinically detectable pleural effusions and no contraindication to the procedure.

PERSPECTIVES

Although the data reviewed indicate that the diagnosis and treatment of pleural effusions should follow the same rules in the ICU as they do elsewhere, several incompletely resolved issues deserve further investigation. These are summarised in an agenda for future research.

Radiographic abnormalities and exposure to asbestos-contaminated vermiculite in the community of Libby, Montana, USA

Mining, handling, processing, and personal or commercial use of asbestos-contaminated vermiculite have led to widespread contamination of the Libby, Montana, area. We initiated a medical testing program in response to reports of respiratory illness in the community. The purpose of this analysis was to identify and quantify asbestos-related radiographic abnormalities among persons exposed to vermiculite in Libby and to examine associations between these outcomes and participants' self-reported exposures. A cross-sectional interview and medical testing were conducted in Libby from July through November 2000 and from July through September 2001. A total of 7,307 persons who had lived, worked, or played in Libby for at least 6 months before 31 December 1990 completed the interview. Of those, 6,668 participants > or = 18 years of age received chest radiographs to assess the prevalence of pleural and interstitial abnormalities. We observed pleural abnormalities in 17.8% of participants and interstitial abnormalities in < 1% of participants undergoing chest radiography. We examined 29 occupational, recreational, household, and other exposure pathways in the analysis. The prevalence of pleural abnormalities increased with increasing number of exposure pathways, ranging from 6.7% for those who reported no apparent exposures to 34.6% for those who reported > or = 12 pathways. The factors most strongly associated with pleural abnormalities were being a former W.R. Grace worker, being older, having been a household contact of a W.R. Grace worker, and being a male. In addition to being a former W.R. Grace worker, environmental exposures and other nonoccupational risk factors were also important predictors of asbestos-related radiographic abnormalities.

Pleural effusions in the intensive care unit

The incidence of pleural effusions in the intensive care unit varies depending on the screening methods, from approximately 8% for physical examination to more than 60% for routine ultrasonography. Several factors contribute to the occurrence of pleural effusions in intensive care unit patients: large amounts of intravenous fluid are often administered, pneumonia is common, and heart failure, atelectasis, extravascular catheter migration, hypoalbuminemia, or liver disease are present in many intensive care unit patients. In surgical intensive care units, cardiac or abdominal surgery is often followed by pleural effusions, and in trauma patients, hemothorax is a dreaded event. Because no clinical parameter excludes pleural infection, and because of the impact of thoracentesis on diagnosis and treatment, this procedure should be performed unless contraindicated. Thoracentesis is safe in mechanically ventilated patients. The author discusses the following points regarding pleural effusions in the intensive care unit: screening intensive care unit patients for pleural effusion, safety of thoracentesis in patients receiving invasive mechanical ventilation, distinguishing exudates from transudates, and diagnosing and managing infected pleural effusions in critically ill patients. Lastly, the author suggests a research agenda for pleural effusions in intensive care unit patients.

A longitudinal study of chest radiographic changes of workers in the refractory ceramic fiber industry

STUDY OBJECTIVE

This industry-wide longitudinal study examines chest radiographic changes of workers manufacturing refractory ceramic fibers (RCF).

DESIGN

Chest radiographs were obtained every 3 years and were interpreted using the 1980 International Labour Organization classification for pneumoconiosis. Three exposure metrics were calculated: duration and latency in a production job, and cumulative exposure (fiber-months per cubic centimeter).

PARTICIPANTS

The radiographic survey included 625 current workers at five manufacturing sites and 383 former workers at two of the five sites.

MEASUREMENTS AND RESULTS

Pleural changes were seen in 27 workers (2.7%). Of workers with > 20 years of latency from initial production job or 20 years of duration in a production job, 16 workers (8.0%) and 5 workers (8.1%) demonstrated pleural changes, respectively. Results from the cumulative exposure analysis (> 135 fiber-months per cubic centimeter) demonstrated a significant elevated odds ratio (OR) of 6.0 (95% confidence interval [CI], 1.4 to 31.0). The incidence of irregular opacities at profusion categories > or = 1/0 was similar to other nonspecified dust-exposed worker populations at 1.0%, and showed a nonsignificant elevated OR in regard to cumulative fiber exposure of 4.7 (95% CI, 0.97 to 23.5).

CONCLUSIONS

RCF are significantly associated with pleural changes that were predominantly pleural plaques, but have not resulted in a statistically significant increase in interstitial changes.

Low molecular weight heparin for the prevention of deep venous thrombosis: a suitable monitoring in elderly patients?

Monitoring of anti-Xa activity (aXa) levels is not routinely required in patients receiving enoxaparine at prophylactic dosages, since aXa is supposed to stay below the manufacturer's recommended range in patients treated for venous thrombosis (0.5-1 IU/ml). In order to aXa in elderly subjects receiving prophylactic enoxaparin, 68 consecutive patients (mean age 82.5 +/- 10.7 years) hospitalized in a medical department receiving 4000 IU enoxaparin daily subcutaneously for the prevention of venous thromboembolic disease were studied. After the first injection of enoxaparin, the aXa of 57.4% patients was superior to 0.5 IU/ml while 69.4% had an aXa higher than 0.5 after 8.4 +/- 1.2 days. A negative relationship between aXa and body weight and a trend towards a positive correlation between aXa and age but not with creatinine clearance were noted. Our findings question the opportunity to monitor aXa in elderly patients receiving 4000 IU enoxaparin as antithrombotic prophylaxis.