Nonfatal Occupational Injury Surveillance Data: Examples from Michigan

Posted on by Kenneth D. Rosenman, MD; Mary Jo Reilly, MS; and Ling Wang, PhD

The importance of developing a tracking system for occupational fatalities, injuries and illnesses was recognized in the original Occupational Safety and Health (OSH) Act of 1970. The Secretary of Labor at that time elected to delegate responsibility to collect, compile, and analyze occupational safety and health statistics. Despite the authority in the OSH Act to cover all workers, the Bureau of Labor Statistics (BLS) in the Department of Labor decided to base their data collection program on an employer-based survey. Accurate and timely surveillance data are needed to identify causes of injury and illnesses, monitor prevention activity, plan interventions and evaluate the efficacy of these interventions. Unlike general public health surveillance, employers are a potential source of work-related injury and illness surveillance data.

The BLS collects and analyzes these occupational safety and health statistics using the employer-based Survey of Occupational Injuries and Illnesses (SOII). The BLS SOII does not capture all injuries as it is a weighted random sample of employers. Also, it excludes the self-employed, workers on farms with 10 or fewer employees, private household workers, and Federal government workers. The SOII selects employers stratified by industries from the 44 participating states and sufficient employers from non-participating states to produce national estimates. State estimates are only provided for the participating states. Each case reported by an employer is weighted according to the stratified selection to allow extrapolation from the employers surveyed and the cases they reported to derive a national estimate. Individual cases and weighting are maintained as confidential information.

Underreporting by employers of work-related injuries and illnesses is well recognized, as discussed in two National Academy of Sciences’ Reports.1, 2 The accuracy of employer-based survey data is compromised in part due to how individual cases reported by employers are weighted; a non-report by an employer significantly amplifies the number of unreported cases in final national and state estimates.

The state of Michigan uses a multi-source reporting system funded by the National Institute for Occupational Safety and Health (NIOSH) which includes a reporting requirement by hospitals and emergency departments to regularly submit work-related injuries and illnesses to the state as part of Michigan’s Multi-Source Injury and Illness Surveillance System. Michigan is one of 23 states currently funded by NIOSH to conduct state-based surveillance for occupational injuries and illnesses.5

A 2024 report on underreporting of amputations by employers in Michigan found that less than 50% of work-related amputations were reported by employers to OSHA,3 specifically noting that:

  • Only 42% of work-related amputations were reported by employers.
  • Employer compliance with reporting was significantly lower in agriculture, forestry, fishing, and hunting (15%); construction (27%); retail trade (21%); arts, entertainment, and recreation (8%); accommodation and food services (13%); and other services (27%).
  • Large employers and unionized employers were significantly more likely (68% and 93%, respectively) and small employers were significantly less likely (18%) to report an amputation.
  • Enforcement inspections at workplaces where the amputations occurred found that employers had not corrected the hazards that caused the amputation in 55% of the workplaces.

A 2023 publication on employer compliance with reporting requirements in Michigan found that employers only reported 44% of the most severe work-related injuries and illnesses that required hospitalization4. Companies with 250 or more employees were significantly more likely to comply (68%) and small companies with 10 or fewer employees were significantly less likely to comply (33%).

An interesting aspect of both of these Michigan reports is the marked under count of work-related injuries noted even when employers directly report. Some of the SOII undercount can be ascribed due to the weighting involved with the sampling process of the survey and the amplification of non-reports. This is not an issue with the undercount seen with the direct reporting that is required by the OSHA amputation and hospitalization reporting requirements.

Reasons for employers not reporting injuries can include a lack of awareness of the requirement, a lack of awareness of the injury, skepticism of its work-relatedness, or cost-shifting to avoid increased workers’ compensation costs. Employer reporting can be impacted by differences in industry sector, employer size and unionization.

The data from Michigan on amputations and hospitalizations show the benefit of a multi-surveillance system for capturing injury data at the state level. Improved reporting can help identify hazards and help target safety-related preventive and intervention efforts in industries that might otherwise be overlooked.

Kenneth D. Rosenman, MD, is a Professor of Medicine and Chief of the Division of Occupational and Environmental Medicine at Michigan State University.

Mary Jo Reilly, MS, epidemiologist, Division of Occupational and Environmental Medicine at Michigan State University.

Ling Wang, PhD, is a biostatistician and an Associate Professor in the Division of Occupational and Environmental Medicine at Michigan State University.

More information about the Michigan program can be found at:

This research was conducted under research cooperative agreement award U60OH008466 supported by the Centers for Disease Control and Prevention National Institute for Occupational Safety and Health (CDC/NIOSH) under CDC funding opportunity PAR-20-312. The contents are those of the author(s) and do not necessarily represent the official views of, nor an endorsement, by CDC/HHS, or the U.S. Government. This blog is part of a series highlighting extramural research funded by NIOSH through the Office of Extramural Programs.



  1. NRC (National Research Council). Counting Injuries and Illnesses in the Workplace: Proposals for a Better System. Washington, DC: National Academy Press.1987.
  2. National Academies of Sciences, Engineering, and Medicine. A Smarter National Surveillance System for Occupational Safety and Health in the 21st Century. Washington, DC: The National Academies Press. 2018.
  3. Reilly MJ, Wang L, Rosenman KD. Evaluation of the Characteristics of Injured Workers and Employer Compliance with OSHA’s Reporting Requirement for Work-Related Amputations. Am J Ind Med 2024.
  4. Reilly MJ, Wang L, Rosenman KD. Evaluation of the characteristics of workers injured on the job requiring hospitalization, and employer compliance with OSHA’s reporting requirement for these work-related hospitalizations. Am J Ind Med. 2023;66:109-122.
  5. NIOSH research award to Michigan State University, Expanded Program in Occupational Injury and Illness Surveillance.


















Posted on by Kenneth D. Rosenman, MD; Mary Jo Reilly, MS; and Ling Wang, PhD

Post a Comment

Your email address will not be published. Required fields are marked *

All comments posted become a part of the public domain, and users are responsible for their comments. This is a moderated site and your comments will be reviewed before they are posted. Read more about our comment policy »

Page last reviewed: January 26, 2024
Page last updated: January 26, 2024