Lost Workday Incident Rate

Lost workday incident rate, abbreviated as LWIR, is the frequency of workplace injuries or illnesses that result in lost workdays.  It is a variation of injury rate metrics that specifically focuses on incidents that cause employees to miss workdays beyond the day of the injury.

Lost Workday Incident Rate helps organizations understand the impact of workplace injuries and illnesses on productivity and employee well being.  A lower LWIR indicates fewer incidents resulting in lost workdays relative to the number of hours worked, suggesting better safety performance.  Conversely, a higher LWIR indicates a higher frequency of incidents resulting in lost workdays and may indicate areas where safety measures need to be strengthened or where specific hazards need to be addressed

 

Lost Workday Incident Rate formula The constant is usually 200,000 work hours, representing the equivalent of 100 full time employees working 40 hours per week for 50 weeks in a year.  However, this constant may vary depending on the organization or jurisdiction.

\( LWIR \;=\;  (TNDL \;/\; TNHW) \; 200,000 \)

Symbol

\( LWIR \) = lost workday incident rate

\( TNDL \) = total number of days lost due to injury of illness

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