Once the gold standard of environment, health, and safety (EHS) metrics, the Total Recordable Incident Rate (TRIR) is now essentially meaningless—when considered alone, that is. The safety performance of an organization is far too complex to be condensed into a simple formula, and EHS managers must respect and appropriately respond to that complexity.
An excellent report on this topic, “The Statistical Invalidity of TRIR as a Measure of Safety Performance,” addressed the complexity of safety directly: “[S]afety is a chaotic system due to the interfaces between people, culture, policies, regulations, equipment and other external factors (e.g. economy, weather, natural events, etc.)” The November 2020 report, released by the Construction Safety Research Alliance (CSRA) and authored by Dr. Matthew Hallowell, Mike Quashne, Dr. Rico Salas, Dr. Matt Jones, Brad MacLean, and Ellen Quinn, also revealed four key takeaways from a statistical analysis of 17 years of data and 3.2 trillion work hours:
“There is no discernible association between TRIR and fatalities;
The occurrence of recordable injuries is almost entirely random;
TRIR is not precise and should not be communicated to multiple decimal points of precision; and
In nearly every practical circumstance, it is statistically invalid to use TRIR to compare companies, business units, projects, or teams.”
With this in mind, let’s take a closer look at TRIR, how it has become increasingly less valuable as a solitary metric, and what EHS managers should be doing to more accurately measure safety success.
Don’t get us wrong—while the TRIR should no longer be considered the end-all-be-all of safety measurement, the metric itself isn’t going anywhere. Among other reasons, your incident rate is a cornerstone of your annual OSHA reporting and is likely to remain a key part of this compliance obligation.
Essentially, two values are needed to compute TRIR: Incidents and time. Here is a simple formula to apply in calculating TRIR:
TRIR = The total number of injuries/illnesses ÷ Total hours worked by all employees x 200,000 hours
First, let’s look at the incident value. A “recordable” injury or illness, as opposed to simple first aid, is clearly defined by the Occupational Safety and Health Administration (OSHA) and includes such incidents as work-related fatalities or any work-related injury or illness that results in loss of consciousness, days away from work, restricted work, or transfer to another job. You can check out more tips on discerning recordables from first aid in this article.
Now, for the time value. After determining total hours worked, you may be wondering why it’s necessary to multiply by 200,000 hours. This figure at the end of the equation represents the hours that 100 employees would work during a typical year made up of 40-hour workweeks with 2 weeks off per year. By incorporating this into the formula, it creates TRIRs that can be used to compare injury rates within any industry, whether a specific facility has 10 workers or 10,000.
So, while these data alone may not be very helpful for individual organizations looking to improve safety performance, TRIRs can be illustrative for public health and safety agencies. The ability to quickly compare incident rates can help prompt the creation of new health and safety guidance and/or regulation as well as direct more effective or targeted enforcement efforts.
However, many organizations continue to over-rely on TRIR in important discussions of workplace safety.
Perhaps because of its tenure as a prominent safety metric, TRIR continues to be a prime metric of performance for many organizations, and its influence can be seen from the jobsite all the way up through the C-suite’s board room. In fact, TRIR is one of the primary, if not the primary, safety metric considered by executives because it is the type of hard data that can easily inform decisions. It can be clearly reported and used as a benchmark; it can be used to evaluate managers or potential contractors; it could affect insurance premiums; it’s a simple number to present to investors, customers, or others in the general public concerned about workplace safety.
So, what’s the problem?
One problem with this is that the severity of incidents is not considered within the context of an organization’s TRIR. “[A] four-stich cut to the finger is counted in the same way as a fatality,” notes CSRA’s report, “and a near miss with the potential to be fatal is not in the TRIR metric at all.”
Another problem noted by the study is that it could potentially take many, many worker-hours of exposure before TRIR even becomes statistically meaningful. The short time frame that TRIR is typically reported (i.e., annually), combined with the hopefully infrequent and also quite likely random occurrence of a recordable injury, further makes TRIR an unstable—and therefore unreliable—statistic.
And, finally, the simple fact remains that TRIR is a lagging indicator, and while these metrics aren’t necessarily “falling out of favor,” it is recognized now that lagging and leading indicators must both be considered as complementary parts of successful EHS metric analysis. Without additional data to support it, TRIR is useless.
To make the metric meaningful, TRIR must live hand-in-hand with such common leading metrics as:
Frequency and completion rates of employee health and safety training;
Near-miss reports; and
Other metrics that are more lagging in nature should also be used to support TRIR. For example, Serious Injury and Fatality (SIF) rates can be used to close the previously-mentioned severity blind spots in traditional TRIRs, and comparing SIF to TRIR will provide a better indication of the severity of your recordable (and non-recordable) incidents.
To navigate the complexities of EHS metrics, a parametric analysis approach is recommended. While that term may sound like it complicates things even further, it is a built-in part of Dakota Software’s Incident and Accident Management solutions, which are used to capture relevant safety data and provide exploration tools for qualitative analysis. Through our parametric filtering, EHS managers can recognize trends and subtle correlations between data fields that might have otherwise gone unnoticed.