The Definition of Lost Time Injury (LTI)

Definition of Lost Time Injury (LTI)

A lost time injury (LTI) is a work-related injury or illness that results in the worker being unable to work their next full scheduled shift or workday. The day of the injury itself is usually not counted. If an employee is hurt on Tuesday and cannot return for Wednesday's shift, the case is generally classed as a lost time injury.

LTIs are one of the most common lagging indicators in workplace safety. They are used to calculate the lost time injury frequency rate (LTIFR) and are widely reported in Australia, the UK, Canada, mining, oil and gas and many multinational companies.

In the United States, OSHA recordkeeping does not use the term LTI. Instead, it classifies cases that involve days away from work, restricted work or job transfer, which are used to calculate the DART rate. A US "days away" case is similar to an LTI, but definitions differ in details, so companies should be careful when comparing figures across countries.

What Counts as a Lost Time Injury

Usually included

• Injuries or illnesses caused or made worse by work that keep the worker off work for at least one full shift after the day of injury.
• Fatalities and permanent disabilities, which are generally counted as LTIs.
• Occupational illnesses, such as work-related musculoskeletal disorders, where they cause time off.

Usually not included

• First aid cases where the worker returns to normal duties.
• Medical treatment cases where the worker returns to work for the next shift.
• Restricted or modified duty cases, which many organizations track separately.
• Injuries that are not work related.

Organizations should write down their own LTI definition and apply it consistently, especially when contractors or several countries report into one system.

Managing Lost Time Injuries

Reporting and investigation

Every LTI should be reported promptly, recorded accurately and investigated to find root causes. Incident investigation should focus on what in the work, equipment or system allowed the injury to happen, and lead to corrective actions that prevent a repeat.

Return to work

A structured return-to-work program helps injured workers recover and come back safely, often through suitable alternative or modified duties. This supports the worker and reduces the cost of the injury.

Avoiding misuse of LTI targets

LTI numbers can be pushed down without making work safer. For example, workers may be pressured not to report injuries, or brought back on light duty to avoid recording a lost day. These practices hide risk and damage trust. Organizations should use LTIs together with leading indicators and measures of serious injury potential.

Example of Lost Time Injury

At a manufacturing plant, an operator strained his lower back while manually lifting a heavy die during a changeover on a Thursday. He went home early, saw a doctor that evening and was told to rest. He was unable to work his scheduled Friday shift and returned on Monday on modified duties.

Because he missed his next full scheduled shift, the plant recorded the case as one lost time injury. The investigation found that a die cart had been out of service for weeks, so operators had been lifting dies by hand. The plant repaired the cart, added a backup lifting aid and updated its changeover procedure.

Frequently Asked Questions: Lost Time Injury

Does the day of the injury count as lost time?

Usually no. Most definitions count lost time starting from the next full scheduled shift or day after the injury.

Is an LTI the same as a recordable injury?

No. A recordable incident under OSHA includes many cases that do not involve lost time, such as medical treatment beyond first aid. An LTI is a narrower category.

Are restricted duty cases lost time injuries?

Many organizations do not count restricted or modified duty cases as LTIs and track them separately, but definitions vary. Check your company or regulator's definition.