To test the validity of self-reported work-related illness data from the LFS, a sample of respondents reporting a work-related illness in the 2010 LFS were re-interviewed and asked for further details about their illness and its connection with work. With their permission, their doctor was also contacted and asked for further information and a view of the link between the illness and work. An expert panel was convened to review all this information and make an assessment of the nature of the link.
Results of the investigation5 (published in March 2013) concluded that self-reports of work-related illness are broadly reliable. The level of possible mistaken reports will to some extent be counter-balanced by opposite biases. In particular, just as individuals may ascribe the cause of their illness to work when there is no such link, there will be others who fail to recognise a link with working conditions when there is one. Given this, and the fact that there is no available –measure of work-related illness without some kind of error, it is better to continue to work with estimates as they emerge from the LFS. Leaving them as they are directly reflects the survey process, and maintains continuity with past data in the series.
A similar follow-up study was completed in 19956, and the message was consistent with the latest study. Results are reasonably reliable and when sensibly interpreted, surveys of self-reports provide valid information not available from other sources.
The level of reliability (from both studies), together with the statistical advantages of a large nationally representative sample providing a wide range of demographic and employment-related data, justifies the use of this measure as a major component of a range of statistical measures of work-related illness.
5 J R Jones, J T Hodgson and S Webster: Follow-up and assessment of self reports of work-related illness in the Labour Force Survey
6 J R Jones, J T Hodgson, T A Clegg and R C Elliott: Self-reported work-related illness in 1995: Results from a household survey