title: Impact of body mass index on the detection of radiographic localized pleural thickening.
abstract: OBJECTIVE
  Subpleural fat can be difficult to distinguish from localized pleural thickening (LPT), a marker of asbestos exposure, on chest radiographs. The aims of this study were to examine the influence of body mass index (BMI) on the performance of radiograph readers when classifying LPT and to model the risk of false test results with varying BMI.
  
  
  METHODS
  Subjects (n = 200) were patients being screened or treated for asbestos-related health outcomes. A film chest radiograph, a digital chest radiograph, and a high-resolution computed tomography (HRCT) chest scan were collected from each subject. All radiographs were independently read by seven B readers and scored using the International Labour Office system. HRCT scans, read by three experienced thoracic radiologists, served as the gold standard for the presence of LPT. We calculated measures of radiograph reader performance, including sensitivity and specificity, for each image modality. We also used logistic regression to estimate the probability of a false-positive and a false-negative result while controlling for covariates.
  
  
  RESULTS
  The proportion of false-positive readings correlated with BMI. While controlling for covariates, regression modeling showed the probability of a false-positive result increased with increasing BMI category, younger age, not having pleural calcification, and among subjects not reporting occupational or household contact asbestos exposure.
  
  
  CONCLUSIONS
  Clinicians should be cautious when evaluating radiographs of younger obese persons for the presence of asbestos-related pleural plaque, particularly in populations having an anticipated low or background prevalence of LPT.
authors: Division of Toxicology and Human Health Sciences, Agency for Toxic Substances and Disease Registry, 4770 Buford Highway NE, MS F57, Atlanta, GA 30341. Electronic address: TLarson@cdc.gov.
authors: Theodore C
authors: TC
authors: Larson
authors: Department of Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, MI.
authors: Alfred
authors: A
authors: Franzblau
authors: Division of Toxicology and Human Health Sciences, Agency for Toxic Substances and Disease Registry, 4770 Buford Highway NE, MS F57, Atlanta, GA 30341.
authors: Michael
authors: M
authors: Lewin
authors: National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, GA.
authors: Alyson B
authors: AB
authors: Goodman
authors: Division of Toxicology and Human Health Sciences, Agency for Toxic Substances and Disease Registry, 4770 Buford Highway NE, MS F57, Atlanta, GA 30341.
authors: Vinicius C
authors: VC
authors: Antao
mesh_terms: D000273:Adipose Tissue / Q000000981:diagnostic imaging*; D000328:Adult; D000368:Aged; D001194:Asbestos / Q000009:adverse effects; D001195:Asbestosis / Q000000981:diagnostic imaging* / Q000209:etiology; D015992:Body Mass Index; D003937:Diagnosis, Differential; D004781:Environmental Exposure / Q000009:adverse effects; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008297:Male; D009009:Montana; D015588:Observer Variation; D010994:Pleura / Q000000981:diagnostic imaging*; D010995:Pleural Diseases / Q000000981:diagnostic imaging* / Q000209:etiology; D013902:Radiography, Thoracic; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D001194:Asbestos
keywords: Radiograph; pneumoconiosis; predictive values