Observed and Expected Mortality in Cohort Studies

Details

• Personal Author:
  Cole SR ; Keil AP ; MacLehose RF ; Richardson DB ; Cole SR ; Keil AP ; MacLehose RF ; Richardson DB
• Description:
  Epidemiologists often compare the observed number of deaths in a cohort with the expected number of deaths, obtained by multiplying person-time accrued in the cohort by mortality rates for a reference population (ideally, a reference that represents the mortality rate in the cohort in the absence of exposure). However, if exposure is hazardous (or salutary), this calculation will not consistently estimate the number of deaths expected in the absence of exposure because exposure will have affected the distribution of person-time observed in the study cohort. While problems with interpretation of this standard calculation of expected counts were discussed more than 2 decades ago, these discussions had little impact on epidemiologic practice. The logic of counterfactuals may help clarify this topic as we revisit these issues. In this paper, we describe a simple way to consistently estimate the expected number of deaths in such settings, and we illustrate the approach using data from a cohort study of mortality among underground miners. [Description provided by NIOSH]
• Subjects:
  Cohort Studies Epidemiology Mining Mortality Occupational Health Safety
• Keywords:
  Author Keywords: Cohort Studies Cohort Studies Exposure Assessment Long Term Exposure Long Term Study Mortality Mortality Data Mortality Rates Mortality Studies Quantitative Analysis Standardized Mortality Ratio Statistical Analysis Statistics Underground Miners

  More +
• ISSN:
  0002-9262
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article ; Journal Article
• Place as Subject:
  Colorado ; Minnesota ; North Carolina ; OSHA Region 4 ; OSHA Region 5 ; OSHA Region 8
• CIO:
  National Institute for Occupational Safety and Health (NIOSH) ; National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health ; Workplace Safety & Health
• Location:
  North America ; North America
• Pages in Document:
  479-486
• Volume:
  185
• Issue:
  6
• NIOSHTIC Number:
  nn:20052106
• Citation:
  Am J Epidemiol 2017 Mar; 185(6):479-486
• Contact Point Address:
  Dr. David B. Richardson, Department of Epidemiology, School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
• Email:
  david.richardson@unc.edu
• Federal Fiscal Year:
  2017
• NORA Priority Area:
  Mining ; Oil and Gas Extraction ; Mining ; Oil and Gas Extraction
• Performing Organization:
  University of North Carolina, Chapel Hill
• Peer Reviewed:
  True
• Start Date:
  20150901
• Source Full Name:
  American Journal of Epidemiology
• End Date:
  20170831
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:ffe919dfb2c86d13fd5c9b5c4689c054e877b561df6c7aba6e5943303f99bfbb45c74d50a5959229399386d6ec2b50e34dfa568f9184b3235610b96e3b8edce1
• Download URL:
  https://stacks.cdc.gov/view/cdc/211697/cdc_211697_DS1.pdf
• File Type:
  [PDF - 129.85 KB ]