Lost Time Injury Frequency Rate

Lost time injury frequency rate, abbreviated as LTIFR, is used to assess the frequency of workplace injuries that result in lost time from work.  It is a variation of the injury frequency rate (IFR) that focuses specifically on injuries severe enough to cause employees to miss work.

LTIFR provides organizations with a specific measure of the frequency of injuries that lead to lost work time, which can help in evaluating the effectiveness of safety programs and identifying areas for improvement in preventing workplace injuries.  A lower LTIFR indicates fewer lost time injuries relative to the number of hours worked, suggesting better safety performance.  Conversely, a higher LTIFR suggests a higher frequency of injuries resulting in lost time and may indicate areas where safety measures need to be strengthened.

 

Lost Time Injury Frequency Rate formula The constant 1,000,000 is used to normalize the rate to the number of lost time injuries that would occur if 1,000 employees worked full time for a year (1,000,000 hours).

\( LTIFR =  (TNLTI \;/\; TNHW) \; 1,000,000 \)

Symbol

\( LTIFR \) = lost time injury frequency rate

\( TNLTI \) = total number of lost time incidents

\( TNHW \) = total number of hours worked by all employees