LTIFR

A lost time injury (LTI) is a work-related injury or illness that results in the worker being unable to work for at least one full day or shift after the day of the injury. Fatalities are usually counted as well.

The day of the injury itself does not normally count. If a worker is hurt in the morning, goes to hospital and returns to their normal shift the next day, most definitions would record it as a medical treatment injury, not an LTI. Exact definitions are set by the company, the client or the reporting scheme, not by WHS law, so check the standard you are reporting against.

For a deeper look, read TRIFR and LTIFR Explained: The Two Safety Numbers Clients Ask For. Try the free LTIFR Calculator.

The LTIFR calculation is:

LTIFR = (number of lost time injuries x 1,000,000) / total hours worked

The 1,000,000 hours multiplier is the Australian standard and lets you compare a small project with a large company on the same scale. Use the same period for both figures, usually a rolling 12 months, and include subcontractor hours and injuries if your reporting scope covers them.

Worked example. A builder's projects record 3 lost time injuries in the last 12 months. Total hours worked across all workers in that period are 450,000.

LTIFR = (3 x 1,000,000) / 450,000 = 6.67

That means 6.67 lost time injuries for every million hours worked. Most builders report it monthly as a rolling 12 month figure, so a single injury does not swing the result as sharply as it would on a monthly rate.

LTIFR only counts injuries that cost at least a full shift. TRIFR (total recordable injury frequency rate) also counts medical treatment and restricted work injuries. For the same period, TRIFR will always be equal to or higher than LTIFR.

LTIFR has a known weakness. If an injured worker is put on alternative duties the next day, the injury is not an LTI, even if it was serious. That is why many head contractors and government clients now ask for TRIFR as well, and why LTIFR should be read alongside severity measures such as days lost and leading indicators such as inspections and observations.

• Using the wrong multiplier. Australia uses 1,000,000 hours. Some overseas measures use 200,000 hours, so figures are not comparable.

• Estimating hours. Use actual hours from timesheets or site sign-ins, not headcount multiplied by a guess. Overstated hours make the rate look better than it is.

• Leaving out subcontractors. On most projects subcontractors work the majority of hours. Leaving them out distorts the rate.

• Managing the number instead of the risk. Pressuring workers back on light duties to avoid an LTI hides injuries rather than preventing them.