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Introducing LTASR, a new R package based on the NIOSH Life Table Analysis System
  1. Stephen J Bertke,
  2. Kaitlin Kelly-Reif
  1. National Institute for Occupational Safety and Health, Division of Field Studies and Engineering, Cincinnati, Ohio, USA
  1. Correspondence to Dr Stephen J Bertke, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Cincinnati, OH 45226, USA; inh4{at}

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For over 50 years, the National Institute for Occupational Safety and Health (NIOSH) has aided epidemiologists in the analysis of occupational cohort studies with the Life Table Analysis System (LTAS).1 LTAS simplifies person-year analyses, which is a central feature of occupational epidemiology research. LTAS is regularly used in occupational epidemiology studies to calculate standardised mortality ratios (SMRs). SMRs continue to be used in occupational epidemiology to compare the mortality experience of a cohort to a national or regional population. While there are limitations to SMRs, such as the inability to evaluate a dose–response association and bias towards the null from the healthy worker effect, SMRs remain an important tool in characterising the overall occupational experience of workers across different industries. SMRs are also an important surveillance tool in occupational and environmental settings. Many occupational cohort studies have used the NIOSH-LTAS system to conduct seminal research, such as a study of first responders to the World Trade Center disaster2 and a study of neurodegenerative …

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  • Contributors SJB was the principal author of the LTASR code being described. SJB and KK-R thoroughly tested the program as well as authored and reviewed drafts of the letter.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Disclaimer The findings and conclusions in this report are those of the author(s) and do not necessarily represent the official position of the National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention.

  • Competing interests None declared.

  • Provenance and peer review Not commissioned; internally peer reviewed.