In a study1 that has implications for preventing slip injuries in healthcare, researchers at the National Institute for Occupational Safety and Health (NIOSH) found that wearing slip-resistant shoes dramatically reduced workers’ compensation claims for school food service workers.

The study included some 17,000 food service workers from 226 school districts.

“Workers were clustered by school district, and the districts were randomly assigned either to a group that received no-cost, five-star rated, slip-resistant shoes or to a group that generally bought their own slip-resistant shoes,” NIOSH reports.2 “Investigators looked specifically at workers’ compensation injury claims caused by slipping on wet or greasy surfaces, the type of incident that the shoes were designed to prevent.”

The group given the slip-resistant shoes saw a 67% reduction in claims for slip injuries. No decline was seen in the control group. “The findings revealed a baseline measure of 3.5 slipping injuries per 10,000 months worked among the intervention group, which was reduced to 1.1 slipping injuries per 10,000 months worked in the follow-up period when slip-resistant shoes were provided,” NIOSH researchers reported.


Hospital Employee Health asked lead author Jennifer L. Bell, PhD, a research epidemiologist in the NIOSH Division of Safety Research, for additional comment in the following interview, which has been edited for length and clarity.

HEH: What are the implications of these findings for healthcare workers?

Bell: Any worker who encounters wet or greasy flooring conditions could potentially benefit from the use of slip-resistant footwear (SRF). In our slip, trip, and fall (STF) research3 in hospitals, food services workers had the highest rates of overall STF-related injury claims of all worker groups in the hospitals, followed by parking, valet and transport workers, emergency medical service workers, and custodial and housekeeping workers. From our STF research in nursing care facilities, nursing aides and food services workers had the highest rates of overall STF-related injury claims. Anecdotally, from our time spent observing food services operations in hospitals and schools, food services workers and housekeeping custodial workers are frequently exposed to wet, greasy conditions.

HEH: How many healthcare slips were related to slick and wet surfaces? Given the findings of this new study, is it likely that many of those could be prevented by wearing the shoes used in the study?

Bell: In our NIOSH study looking at STFs in three acute care hospitals4, the majority (23.6%) of STF-related workers’ compensation injury claims were caused by contact with liquid contamination: water, body or cleaning fluid, grease, floor wax, and slick or slippery spots. Similarly, in our NIOSH study of nursing care facilities5, the majority (36%) of STF-related workers’ compensation injury claims were caused by contact with liquid contamination. Another studyanalyzed STF-related injury data from six governmental and one industrial injury surveillance systems in the United States, United Kingdom, and Sweden to isolate the contribution of slipperiness to STF injuries. Slipperiness or slipping was found to contribute to between 40% and 50% of fall-related injuries. Slipperiness was more often a factor in same-level falls than in falls to lower levels.7-9

HEH: Based on the study results, would you recommend the use of slip-resistant shoes in healthcare?

Bell: This NIOSH study adds to the body of evidence that using highly rated SRF can lead to a reduction in injuries caused by slipping on wet and greasy flooring, and that the healthcare industry would likely benefit from increased SRF use.

HEH: Can you provide the most recent data on injuries resulting in STFs in healthcare?

Bell: Bureau of Labor Statistics10 data for characteristics of work-related injuries involving days away from work in 2017 show that total STF is the second-leading cause of injury in the healthcare and social assistance industry, at 26.8%. The leading cause is overexertion/bodily reaction, which accounts for some 38% of total injuries.

HEH: The use of slip-resistant footwear was highly effective in reducing falls. Can you describe the features of this shoe that prevent slippage?

Bell: There are many factors that affect a shoe’s slip-resistance performance, with tread pattern, sole material composition, and wear of major importance. NIOSH selected one brand of slip-resistant footwear for use in this study based on highly ranked performance in wet, greasy conditions. We used the GRIP11 slip resistance rating scheme for footwear, which uses rigorous scientific testing to measure and grade the slip resistance of footwear. We also considered the availability of a variety of sizes and styles of the upper portion of the shoe, and availability for purchase by the general public. In addition to the GRIP rating scheme, information and resources are becoming increasingly available to help employers and workers know how to select SRF with a high degree of slip resistance in a variety of conditions.

HEH: Is cost a factor, thus making employer-provided shoes a key to this intervention?

Bell: In our study, the SRF was offered free to workers in the intervention group. Workers in the control group had the ability to purchase the same SRF through a worksite payroll deduction program, but generally had to pay for the SRF themselves. Our study found that 94% of workers in the intervention group who were offered free SRF obtained the SRF, while only 20% of the workers in the control group who paid for their own SRF obtained the same SRF. This discrepancy could imply that cost was a factor in obtaining this brand of SRF.

Another study performed by researchers from the former Liberty Mutual Research Institute for Safety found that restaurant workers’ use of SRF was highest (with 91% of workers wearing SRF) in restaurants where footwear was provided and paid for by the employer.

HEH: Would the prevented injuries cover the cost of the shoes for employers?

Bell: Our study was not designed to answer this question. To answer this question, an employer would have to look at a number of factors, such as their current rate of slipping-related workers’ compensation injury claims, the size of the worker population, the cost of each style of shoe purchased, how many hours the workers work each month, employee tenure and turnover, and many other factors that affect the direct and indirect costs associated with worker injuries.

HEH: There is some mention that workers age 55 years and older may be a greater risk of these accidents. Given the number of older workers in healthcare, is the risk of falls increasing?

Bell: Another finding from this research was that prior to the no-cost slip-resistant footwear intervention, workers over 55 years of age had a higher probability of a slip-related workers’ compensation injury claim — 4.2 injuries per 10,000 worker months. Workers under age 55 years had 2.3 injuries per 10,000 worker months. This is of public health significance because there is an increasing trend of more workers over age 55 remaining active in the U.S. workforce. Without intervention, slipping injuries may be an increasing injury problem.


  1. Bell JL, Collins JW, Chiou S, et al. Effectiveness of a no-cost-to-workers, slip-resistant footwear program for reducing slipping-related injuries in food service workers: A cluster randomized trial. Scand J Work Environ Health 2019;45:194-202.
  2. Bell JL, Collins JW, Chiou S, et al. Does slip-resistant footwear reduce slips, trips, and falls in food service? NIOSH Science Blog, July 12, 2019. Available at:
  3. NIOSH. Slip, trip, and fall prevention for healthcare workers. 2010. Available at:
  4. Bell JL, Collins JW, Wolf L, et al. Evaluation of a comprehensive slip, trip, and fall prevention programme for hospital employees. Ergonomics 2008;51:1906-1925.
  5. Bell JL, Collins JW, Tiesman HM, et al. Slip, trip, and fall injuries to nursing care facility workers. Workplace Health Saf 2013;61:147-152.
  6. Chander H, Wade C, Garner JC, et al. Slip initiation in alternative and slip-resistant footwear. Int J Occup Saf Ergon 2017;23:558-569.
  7. Jones T, Iraqi A, Beschorner K. Performance testing of work shoes labeled as slip resistant. Appl Ergon 2018;68:304-312.
  8. Verma SK, Zhao Z, Courtney TK, et al. Duration of slip-resistant shoe usage and the rate of slipping in limited-service restaurants: Results from a prospective and crossover study. Ergonomics 2014;57:1919-1926.
  9. Courtney TK, Sorock GS, Manning DP, et al. Occupational slip, trip, and fall-related Injuries: Can the contribution of slipperiness be isolated? Ergonomics 2001;44:1118-1137.
  10. Bureau of Labor Statistics. Injuries, illnesses, and fatalities: Case and demographic characteristics for work-related injuries and illnesses involving days away from work, calendar year 2017 survey results. Available at:
  11. GRIP. Taking steps against workplace slips. Available at: