The Lost Time Incident Rate (LTIR), often referred to as the Lost Workday Case Rate, is a key metric used in occupational safety and health to measure the frequency of work-related injuries and illnesses that result in an employee being unable to perform their regular job duties for at least one full workday. It's a crucial indicator for assessing the effectiveness of a company's safety programs and identifying areas for improvement.
How is LTIR Calculated?
The formula for calculating LTIR is as follows:
LTIR = (Number of Lost Time Incidents × 200,000) / Total Hours Worked
Where:
Number of Lost Time Incidents: This is the total count of injuries or illnesses that prevented an employee from reporting to work for at least one full day.
Total Hours Worked: This represents the sum of all hours worked by all employees during the period being measured (e.g., a month, quarter, or year). A standard period of 200,000 hours is used for comparison, representing the equivalent hours worked by 100 full-time employees working 40 hours per week for 50 weeks per year.
200,000: This is a constant representing the standard number of hours worked by 100 employees in a year (100 employees × 40 hours/week × 50 weeks/year).
Why is LTIR Important?
A lower LTIR generally indicates a safer workplace. By tracking this rate, organizations can:
Benchmark their safety performance against industry averages.
Identify trends in workplace injuries and illnesses.
Evaluate the effectiveness of implemented safety initiatives.
Demonstrate a commitment to employee well-being.
Potentially reduce insurance premiums and workers' compensation costs.
Interpreting the Results
The resulting LTIR is a rate per 200,000 hours. For example, an LTIR of 2.5 means that for every 200,000 hours worked, there were 2.5 incidents resulting in lost time.
Example Calculation:
Let's say a company experienced 3 lost time incidents over a year where their employees collectively worked 500,000 hours.