Health & Safety Metrics, Part 1 — Incident Metrics
Incident metrics are the lagging indicators at the heart of most safety reporting. Here are the fifteen measures every EHS team should know.
Health and Safety metrics, also known as Health and Safety Key Performance Indicators (KPIs), provide a measurement framework for evaluating the effectiveness of health and safety protocols within the workplace.
With continual monitoring and reporting of these metrics, organisations can quickly identify problem areas and design strategies to improve them.
What are the types of health & safety metrics that businesses should use?
The mix of metrics will differ between industries and sectors, but health and safety metrics can be categorised into:
- Incident Metrics
- Near Miss Metrics
- Inspection and Audit Metrics
- Training Metrics
- Violations Metrics
- Costs and Penalties Metrics
How are health & safety performance metrics measured?
Health & Safety metrics are measured in different ways. This may be a number, a percentage, a ratio or a range.
In this part 1 of our series on health and safety metrics, we'll cover the main metrics related to Incidents / Accidents.
What are the health & safety performance metrics related to incidents and accidents?
Some of the key metrics relating to Incidents are:
- Total Incidents
- Incident Rate
- Incident Frequency Rate
- Total Recordable Incidents
- Total Recordable Incident Rate (TRIR)
- Total Recordable Incident Frequency Rate (TRIFR)
- Total Reportable Incidents
- Injury Incidence Rate (IIR)
- Incident Severity Rate
- Lost Time Injuries
- Total Lost Time
- Lost Time Incident Rate (LTIR)
- Lost Time Incident Frequency Rate (LTIFR)
- Days Away, Restricted or Transferred (DART)
- Days Away, Restricted or Transferred (DART) Rate
1. Total Incidents
Total Incidents is simply the total number of occupational incidents and illnesses logged in a defined period. This could include minor and major injuries and illnesses. This could include incidents that just need first aid or significant medical treatments.
Companies tend to look at the number of incidents each month and year and break down incident data by category, severity, root cause, impact, body part injured etc. Companies also look at incident data by site, factory, depot, department etc.
While number of incidents is a simple and important metric, incidence and frequency rates explained below tend to be more meaningful.
2. Incident Rate
Incident Rate is the estimated number of incidents or illnesses in a reference period divided by the estimated average number of people in employment in the same reference period (typically 12 months). For example, if there are 10 incidents across 50 employees then Incident Rate is 10 / 50 = 0.2
Incident Rate can also be represented as the number of incidents or illnesses in a reference period divided by the total number of hours worked in the reference period.
For example, if there are 10 incidents over a total of 10,000 working hours then the Incident Rate is 10 / 10,000 = 0.001
3. Incident Frequency Rate
Incident Frequency Rate is similar to Incident Rate but is normalised for a specific number of work hours, so the metric can be benchmarked and compared across companies and industries.
This is defined as the number of incidents or illnesses in a reference period divided by the total number of hours worked in the reference period and then multiplied by a constant like 200,000 (e.g. in the US) and 1,000,000 (e.g. in the UK). Typically the metric is calculated over a 12 month reference period.
For example, if there are 10 incidents over a total of 10,000 working hours then the Incident Frequency Rate will be (10 / 10,000) X 200,000 = 200
The constant of 200,000 hours represents 100 employees working 40 hours (full time) per week, for fifty weeks of the year. This mimics an annualised, normalised metric.
4. Total Recordable Incidents
When a workplace related injury or illness occurs, a safety professional must determine 1) if the incident is recordable and then 2) if it is reportable to the country's health and safety authorities (e.g. OSHA in the US, HSE in the UK).
While all types of incidents can be self-recorded, certain types of incidents must be recorded.
Typically, work-related injuries or illnesses that require medical attention beyond first aid are recordable. The requirements may vary by country and province, hence a company should be always aware of the local requirements.
Recordable Incidents are also termed as Case Incidents or Medical Case Incidents in some companies and geographies.
5. Total Recordable Incident Rate (TRIR) or Total Case Incident Rate (TCIR)
TRIR or TCIR is defined as the number of Recordable Incidents or Illnesses in a reference period divided by the total number of hours worked in the reference period and then multiplied by a constant like 200,000 (e.g. in the US). Typically the metric is calculated over a 12 month reference period.
For example, if there are 5 Recordable Incidents or Illnesses over a total of 10,000 working hours then the Total Recordable Incident Rate will be (5 / 10,000) X 200,000 = 100
The constant of 200,000 represents 100 employees working 40 hours (full time) per week, for fifty weeks of the year. This mimics an annualised, normalised metric.
6. Total Recordable Incident Frequency Rate (TRIFR)
TRIFR is a variation of TRIR and is used in geographies in UK, Australia, New Zealand. It is defined as the number of Recordable Incidents or Illnesses in a reference period divided by the total number of hours worked in the reference period and then multiplied by a constant of 1,000,000 hours.
For example, if there are 5 Recordable Incidents or Illnesses over a total of 10,000 working hours then the Total Recordable Incident Frequency Rate will be (5 / 10,000) X 1,000,000 = 500
7. Total Reportable Incidents
When a workplace related injury or illness occurs, a safety professional must determine 1) if the incident is recordable and then 2) if it is reportable to the country's health and safety authorities (e.g. OSHA in the US, HSE in the UK). Total Reportable Incidents is simply the total number of occupational incidents and illnesses reported to authorities in a defined period.
Typically incidents resulting in fatalities, fractures, amputations or illnesses like occupational cancers need to be reported, though this is not an exhaustive list. For OSHA, please see this link for reportable incidents. For RIDDOR reportable incidents in the UK, please see this link.
8. Injury Incidence Rate (IIR)
Injury Incidence Rate is the estimated number of people with a workplace injury or illness in a reference period divided by the estimated average number of people in employment in the same reference period (typically 12 months).
9. Incident Severity Rate
Companies and organisations use severity to determine just how critical or serious the effects of an injury or illness can be. It is calculated by utilising the average number of lost days due to an incident. Incident Severity Rate tends to be calculated in two different ways.
In method 1, Incident Severity Rate = Number of Days Lost / Number of Recordable Incidents within a defined period
In method 2, Incident Severity Rate = (Number of Days Lost / Total number of working hours) X 200,000
The constant of 200,000 represents 100 employees working 40 hours (full time) per week, for fifty weeks of the year. This mimics an annualised, normalised metric.
10. Lost Time Injuries / Lost Time Incident (LTI)
Lost Time Injuries is simply the total number of occupational incidents and illnesses logged in a defined period, that resulted in time lost between the injury / illness and returning to work.
Companies tend to look at the number of Lost Time Injuries incidents each month and year and break down incident data by category, severity, root cause, impact, body part injured etc. Companies also look at LTI data by site, factory, depot, department etc.
11. Total Lost Time
Total Lost Time is simply the amount of time lost due to occupational incidents and illnesses in a defined period. The time elapsed is calculated from when a person left work due to injury / illness to them returning to work. It is usually expressed in full day equivalents.
12. Lost Time Incident Rate / Lost Time Injury Rate (LTIR)
LTIR is defined as the number of Lost Time Injuries or Illnesses in a reference period divided by the total number of hours worked in the reference period and then multiplied by a constant like 200,000 (e.g. in the US). Typically the metric is calculated over a 12 month reference period.
For example, if there are 5 LTIs over a total of 10,000 working hours then the LTIR will be (5 / 10,000) X 200,000 = 100
The constant of 200,000 represents 100 employees working 40 hours (full time) per week, for fifty weeks of the year. This mimics an annualised, normalised metric.
13. Lost Time Incident Frequency Rate (LTIFR)
LTIFR is a variation of LTIR and is used in geographies in UK, Australia, New Zealand. It is defined as the number of Lost Time Incidents in a reference period divided by the total number of hours worked in the reference period and then multiplied by a constant of 1,000,000 hours.
For example, if there are 5 Lost Time Incidents or Illnesses over a total of 10,000 working hours then the LTIFR will be (5 / 10,000) X 1,000,000 = 500
14. Days Away, Restricted or Transferred (DART)
DART stands for "days away, restricted or transferred." DART is a safety metric mandated by OSHA in the US. It is defined as the number of workplace injuries and illnesses that caused employees to miss work days, perform restricted work activities or transfer to another job within one calendar year.
In a nutshell, it measures the number of cases where employees were unable to do their jobs because of a workplace incident or injury in a given year.
15. Days Away, Restricted or Transferred Rate (DART Rate)
DART Rate is defined as the number of workplace injuries and illnesses that caused employees to miss work days, perform restricted work activities or transfer to another job divided by total number of hours worked in the reference period and then multiplied by a constant like 200,000 (e.g. in the US). Typically the metric is calculated over a 12 month reference period.
For example, if there are 5 DARTs over a total of 10,000 working hours then the DART Rate will be (5 / 10,000) X 200,000 = 100
The constant of 200,000 represents 100 employees working 40 hours (full time) per week, for fifty weeks of the year. This mimics an annualised, normalised metric.
How can digital EHS software help with incident related health & safety metrics?
Digital EHS software like SafetyQube can:
- Capture all input data while recording incidents, adding incident details and during investigation
- Automatically calculate the key incident metrics shown above
- Generate charts and trends relating to the key incident metrics shown above
- Allow break down, drill downs and comparisons of metrics across sites, depots, departments etc
- Save time for you to focus on taking actions to improve instead of manual analysis
For part 2 in this series, where we explore near miss metrics, please click here.
SafetyQube calculates your key incident metrics automatically. Book a free demo.
