Measures of workplace injury: Definitions and formulae
The LFS gives estimates on the levels of workplace injury. All estimates are based on an individual's most recent workplace injury in the 12 month reference period, and exclude injuries caused by road accidents since they fall outside HSE's jurisdiction. Information is presented as estimated incidence and rates of all non-fatal injuries, over-3-day absence injuries and over-7-day absence injuries where:
- Estimated injury incidence is the estimated number of people with a workplace injury (excluding injuries caused by road accidents) in the 12 months prior to interview (the reference period);
- Injury incidence rate is defined as the injury incidence estimate divided by the estimated average number of people in employment in the 12 month reference period (this is taken as the average number of people currently employed in January to March);
- All non-fatal injuries include all self-reported workplace injuries (excluding injuries caused by road accidents);
- Over-3-day absence injuries include those self-reported injuries resulting in more than three consecutive (working and non-working) days away from work (not counting the day on which the accident happened);
- Over-7-day absence injuries include those self-reported injuries resulting in more than seven consecutive (working and non-working) days away from work (not counting the day on which the accident happened).
Note: The estimate of the number of people in employment from the LFS is consistent with the International Labour Organisation (ILO) definition of employment. Under this definition employment includes both those who are in work during the reference period and those who are temporarily away from a job (for example, because they were on holiday or off sick).
The formulae used to calculate the incidence estimate and rate of over 3-day absence injury relating to individuals working in the last 12 months for overall and individual characteristics such as age and sex are given by:
| Incidence of over-3-day absence injury | = | The estimated number of people with an over-3-day absence injury at any time during the 12 month reference period. | |
| Incidence rate of over-3-day absence injury per 100 000 workers | = | The estimated number of people with an over-3-day absence injury (excluding injuries caused by road traffic accidents) at any time during the 12 month reference period
Estimated average number in employment in the 12 month reference period (taken as the estimated number of people currently employed in the LFS reference week) |
x 100 000 |
Note: Similar formulae can be used for all non-fatal injuries and over-7-day absence injuries.
For estimates by employment-related variables (such as occupation or industry) these formulae are refined slightly to account for the fact that the LFS only provides detailed information about the job in which the injury was sustained if it was the respondent's current (including second job) or most recent job in the last 12 months. [Although in estimates by employment-related variables, cases of injury sustained in the second job are excluded. This is because the very small number of cases reported against the second job do not warrant the added complexity of allowing for second jobs in the calculations]. No job-related information is available for injuries sustained in other jobs.
| Incidence of over-3-day absence injury sustained in current or most recent job | = | The estimated number of people with an over-3-day absence injury sustained in their current or most recent job at any time during the 12 month reference period. Note:
|
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Incidence rate of over-3-day absence injury sustained in current or most recent job per 100 000 workers |
= | The estimated number of people with an over-3-day absence injury sustained in their current or most recent job (excluding injuries caused by road accidents) at any time during the 12 month reference period Estimated average number in employment in the 12 month reference period (taken as the estimated number of people currently employed in the LFS reference week) |
x 100 000 |
Note: Similar formulae can be used for all non-fatal injuries and over-7-day absence injuries.
The Reporting of Injuries, Diseases and Dangerous Occurrences Regulations (RIDDOR) Reporting Levels
The LFS provides our headline measure on workplace injury, and a more complete view than RIDDOR. A key limitation of RIDDOR is the under-reporting of non-fatal incidents. To aid the interpretation of RIDDOR analysis, estimates of RIDDOR reporting levels overall, by employment status have been derived using results from the LFS. Until 2012/13, this was achieved by comparing non-fatal RIDDOR injury rates which include major and over-3-day injuries with analogous rates from the LFS referred to as reportable non-fatal workplace injury in the calculation below. This rate was constructed with additional LFS injury questions that have been included since 2006/07. They provide details on the nature of the injury and whether it led to hypothermia, heat induced illness or unconsciousness, or required resuscitation, or required admittance to hospital for more than 24 hours.
The formulae used to calculate the estimated RIDDOR reporting level is given below:
Estimated RIDDOR reporting level (%) |
= | The reported rate of RIDDOR incidents of non-fatal workplace injury The estimated self-reported rate of reportable non-fatal workplace injury |
x 100 |
Since 2012/13, the RIDDOR injury definition has been changed (link to the National Archives) to include specified and over-7-day injuries and the closest match to the new definition has been constructed from the LFS.