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Lost Time Injury Frequency Rate (LTIFR)

Last updated: August 31, 2020

What Does Lost Time Injury Frequency Rate (LTIFR) Mean?

Lost time injury frequency rate (LTIFR) refers to the amount or number of lost time injuries, that is, injuries that occurred in the workplace that resulted in an employee's inability to work the next full work day, which occurred in a given period relative to the total number oh hours worked in the accounting period. In many countries, the figure is typically calculated per 1,000,000 hours worked.

LTIFR is considered a lagging indicator, as the results are more meaningful when measured across a large group of workers.

In the U.S., under OSHA. From 1971 to 2001, it was know as Lost Workday Rate . In 2001, it changed to Dart Rate.

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To calculate LTIFR using the standard 1,000,000 hours, use this formula:

Lost time injuries last quarter X 1,000,000 = LTI THEN LTI / total hours worked = LTIFR

Safeopedia Explains Lost Time Injury Frequency Rate (LTIFR)

The lost time injury frequency rate (LTIFR) is calculated using two pieces of essential information: the LTI within a given time frame, and the amount of hours worked in that time frame. The other element of the equation is the standardized rate, that is to say, there are X number of LTIs per a set amount of time. This number can change, but, typically, the LTIFR is calculated per 1,000,000 hours as a standard.

For example, Let's say you want to know what the LTIFR was per 1, 000, 000 hours for the last quarter. You find that there were 5 lost time injuries last quarter, and that 1,584,391 hours were worked.

5 X 1,000,000 = 5,000,000

5,000,000 / 1,584,391 = 3.15

This means that there were 3.15 lost time injuries every 1,000,000 hours worked last year.

Lost time injury frequency rates can be tracked by companies over time to help them gage workplace safety and the effectiveness of safety programs. Metrics such as LTIFR and LTIIR may also be used by regulatory bodies like the Occupational Health and Safety Administration (OSHA). The LTIFR can be used to calculate and compare the frequency rate of occurrence of different types of injuries. The rate can be calculated using lost time injuries, and compared to the calculation using medical treatment injuries.



Lost Time Case Rate (LTCR), Lost Time Incident Rate (LTIR), Lost Time Accident Rate (LTAR)

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