Source specific regular revisions to statistical data
Data Series - Annual reported injury statistics (RIDDOR)
Data published for the most recent year is given a 'p' status (provisional), and a year later is released as final and given an 'r' suffix (revised). For provisional data this allows for late reports and where necessary additional quality checks. No further revisions are made to finalised data (unless there is a methodological improvement or errors are found). Publication of data in this manner attempts to strike a balance between producing data promptly (initially as provisional), and accurately (as final, a year later with minor adjustments).
The changes are usually small, increasing by no more than about 1-2% for non-fatal injuries. Percentage changes between provisional and final for fatal injures can vary more, partly because of the much smaller numbers involved. Finalised fatal numbers can go down as well as up, in the range +/- 2.5%, mainly because all fatalities are investigated in detail, with some talking considerable time to conclude.
Data Series - Annual reported injury rates (RIDDOR)
Employment estimates from the Annual Population Survey (APS) are used as the denominator in the calculation of RIDDOR injury rates. The Office for National Statistics (ONS) is the provider of the APS data. The analysis and interpretation of these data for the purpose of use in injury rate calculations are the sole responsibility of the HSE. Each year, ONS reweight these employment estimates to reflect the latest population estimates. Revisions typically go back three years and will be incorporated into the RIDDOR injury rates at the time of the next scheduled release of injury numbers. Occasionally, more historical revisions are made to the employment series. When these revisions occur, HSE statisticians will make a judgement as to whether they materially impact on the RIDDOR injury rate series and decide whether to incorporate them into the rates.
Data Series - Quarterly, in-year reported deaths (RIDDOR) data
This series covers work-related fatalities that are reportable under RIDDOR, and are updated on a quarterly basis. A consequence of providing detail that is as up-to-date as possible is that many of the cases listed are still under investigation. Therefore, these statistics are released on a provisional basis, and the quarterly figures will be revised during the year up until the time that the annual figures are finalised.
Data Series - Mesothelioma and asbestosis deaths
Statistics for the most recent year are marked as provisional and may be subject to minor revision in subsequent years due to late registrations which are included to ensure the series is as complete and consistent as possible. On publication of figures for the latest year revisions to data for earlier years will be made such that the total for the previous year will typically increase by around 10-15 deaths and the total for the year before that by 1 or 2 deaths.
Data Series - Enforcement data
At first release, HSE enforcement data (notices and prosecutions) are marked as provisional. The following year, data are finalised and no further revisions made. (unless errors are found). The level of revision is minor, typically, being less than 1%.
Data Series – THOR
THOR records reports of cases of work-related illness from members of the THOR surveillance network. There is a system of regular checks with reporters throughout the year, and an annual process of completeness and logic checks before the data are released. Occasionally, specific analyses can identify data errors in individual THOR cases after initial publication. When found, these are corrected immediately in the THOR database, and at the next annual update in the HSE published tables.
Data Series – LFS
HSE follows LFS revision practice to the extent that it materially affects estimates from the health and safety questions. When there is the potential impact, an assessment of the scale is made and a judgement about the need for revision is made.
Data Series - HSE Cost model
Each year HSE produces a revised back series (to 2004/05) to express costs for each year in the current year prices. This is to enable reliable comparisons between years. The revised back series in current year prices will also include revisions to any of the model inputs or assumptions.