As an environmental, health and safety leader, your job requires you to collect a variety of metrics that give you a data-driven look at your safety program. These metrics provide details on specific areas and give you a better idea of where to direct your efforts.
Also known as Lost Time Incident Rate or Lost Time Case, Lost Time Injury (LTI) is one of several metrics you’ll want to track in your EHS department. Here’s what you need to know about Lost Time Injury Rate.
What Is a Lost Time Injury?
A Lost Time Injury refers to incidents that result in an employee missing work due to a work-related injury. Accidents that happen off the clock that affect an employee’s ability to work will not be counted in this metric.
The resulting figure represents the number of lost time injuries per 100 workers in a given period. This is considered a “lagging indicator,” as the figure is calculated using incidents have already occurred. This means that LTI are not a perfect predictor of a company’s future safety performance.
Why It Matters
The higher this measurement, the greater the indication that your safety performance is lacking. Indications of poor safety performance could result in higher insurance premiums. Your best workers may start looking for employment elsewhere under the belief they’re at safety risk while at work.
Also, numerous incidents that are serious enough to result in lost time could lead to bad PR for your company and give you a reputation that will be hard to change.
Granted, a “high” or “low” number can be relative, as safety looks different depending on the industry. It’s important to compare your numbers to your industry's national average.
How to Calculate Lost Time Injury Rate
Lost Time Injury Rate follows a simple formula. Divide the total number of lost time injuries in a certain time period by the total number of hours worked in that period, then multiply by 200,000 to get the LTIR. This number tells you the number of lost time injuries per 100 workers, (equivalent to 2000 hours worked for each of 100 workers).
Note, some companies in certain countries use 1,000,000 instead of 200,000 in the formula described above. The reason for using such large numbers is the number of lost time injuries compared to total number of hours worked is always small. Using a larger number as a baseline makes it easier to interpret. It looks like this:
(LTI / Total # Hours) x 200,000
For simplicity’s sake, let’s say you ended the year with two lost time injuries. If the organization calculated 150,000 hours worked, the resulting metric would reflect 2.67 lost time injuries per 100 workers.
The gravity or severity of the injury is not calculated in this metric (this is called the Injury Severity Rate). Rather, it’s only concerned with the number of lost time injuries, not the actual amount of time lost due to each injury or other contributing details. Many companies see a strong correlation between their LTIR and their Experience Modification Rate (EMR), which is used by insurance companies to measure both past cost of injuries and future risk. The lower the EMR of your business, the lower your worker compensation insurance premiums will be.
Prevention Matters Most
It’s easy to get caught up in safety metrics and data, but don’t let your metrics make you lose sight on what’s most important. Preventing injuries is the main goal, regardless of how good your Lost Time Injury numbers look.
Strengthening your safety program should take priority over any metric. As long as you’re focusing on providing a safe work environment for your employees, your metrics will most likely reflect it.
Further reading: How to Calculate Total Recordable Incident Rate
