This study challenges conventional wisdom of safety measurement with an empirical analysis of 3.26 trillion work hours of total recordable incident rate (TRIR) data and a statistical demonstration of proof.
Parametric and nonparametric statistical analysis revealed that no discernable association exists between TRIR and fatalities.
This analysis also found that the occurrence of recordable injuries is almost entirely random. Further, it found that TRIR is not precise and should not be communicated to multiple decimal points of precision.
Finally, the analysis revealed that in nearly every practical circumstance, it is statistically invalid to use TRIR to compare companies, business units, projects or teams.
Total Recordable Incident Rate (TRIR) has been used as the primary measure of safety performance for nearly 50 years. Simply, TRIR is the rate at which a company experiences an OSHA- recordable incident, scaled per 200,000 work hours. TRIR is based upon a standard definition of a recordable incident that was created and institutionalized in the recordkeeping requirements of the OSH Act of 1970 (BLS, 2019). According to the general criteria, an incident is recordable if it results in work-related injury or illness, requiring medical treatment beyond first aid, that results in loss of consciousness, days away from work, restricted work or transfer to another job (OSHA, 2010). Since organizations conform to this same definition, the TRIR metric has been used to compare industries, sectors, companies and even projects.
TRIR is used in many ways to measure safety performance, from the work site to the boardroom. For example, organizations use TRIR to report results, benchmark against peers, prequalify and select contractors, evaluate the performance of managers and track the impact of safety initiatives (Lofquist, 2010; Manuele, 2008; Wilbanks, 2019). TRIR is also a primary safety metric of concern among executives because it may impact workers’ compensation insurance premiums, influence public image and be scrutinized by potential customers or investors (Lingard et al., 2017; Lofquist, 2010; Ritchie, 2013; Salas, 2020; Truitt, 2012). Although other lagging measures such as days away, restricted or transferred (DART) rates are also considered, no safety metric is as ubiquitous as TRIR.