What Is LTI (Lost Time Injury)?

An LTI is counted from the injury itself, not from how long the resulting paperwork takes: the test is whether the worker was unable to attend their next scheduled shift, regardless of whether that shift was a working day or a rest day on the roster. An injury treated and cleared to return the same shift is not an LTI, even if it required stitches or an X-ray.

LTIFR = (number of lost time injuries ÷ total hours worked) × a measurement base.

The measurement base differs between facilities, some use 200,000 hours and others use 1,000,000, and comparing two rates without knowing which base each one used is meaningless.

Worked example: a facility recorded 3 lost time injuries across 1,200,000 hours worked. On the million-hour base, LTIFR = 2.5.

LTI measures what failed, not what was prevented. A site can run a quarter with a low LTI purely because the specific hazards that happened to materialise were minor ones, while the controls for a much more severe risk sat unproven the whole time. Read alongside leading indicators, LTI says less on its own than its prominence in reporting suggests.

Where multiple contractor crews work the same site, the measurement base each one applies to its own hours can differ from the site owner's, and an LTIFR quoted without stating both the numerator's scope and the base used is not comparable to another site's figure, however close the two numbers look.

• TRIR
• Work injuries
• Safety KPIs

LTI is a lagging indicator: it reports after the fact. Continuous observation on cameras already installed feeds the leading indicators that give a fuller picture before an LTI-level injury happens. Read about the platform.