Stress-related and psychological disorders

Overall scale

There are two main sources of statistics on occupational stress and related disorders in Britain. These are large surveys of the general population that collect self-reported information and reports by specialist physicians through HSE's occupational disease surveillance schemes (THOR).

Several large surveys have collected relevant self-reported information on the prevalence of work-related stress. These include a Self-reported Work-related Illness (SWI) question-set module on the national Labour Force Survey, Psychosocial Working Conditions (PWC) and the Stress and Health at Work (SHAW) study, undertaken in 1998. This latter postal survey collected self-reports on how stressful individuals believed their jobs were and may best be considered as measuring exposure prevalence. This same question was interviewer administered in the later PWC surveys in 2004, 2005, 2006, 2007, 2008 and 2009. Alternatively, the LFS interviewer-administered surveys collect self-reports on ill health attributed to work-related stress. The self-reported data from these LFS surveys provides the most broadly based estimate of the overall prevalence and incidence of work-related stress in Britain, and also the resulting working days lost.

The SWI survey module has been included in the LFS annually since 2003/04, and periodically prior to then (earliest results are from 1990, although only results prior to 2001/02 are directly comparable with later time periods). Results from all surveys consistently indicate that stress and related conditions form the second most commonly reported group of work-related ill-health conditions after musculoskeletal disorders.

It is estimated that work-related stress, depression or anxiety affected 415 000 individuals who had worked in the last 12 months in 2008/09 (prevalence) (Table SWIT3W12), with a corresponding estimated 11.4 million lost working days due to these work-related conditions (Table SWIT1). This represents an estimated average of 27.5 working days lost per affected case and makes stress, depression or anxiety the largest contributor to the overall estimated annual days lost from work-related ill-health in 2008/09.

A further estimated 19 000 people who worked in the last 12 months reported suffering from work-related heart disease in 2008/09 (prevalence) (Table SWIT3W12). Evidence from the 1995 survey suggests most of those reporting work-related heart disease ascribed its cause to work stress. Consequently most of these estimated 19 000 may also represent indirect reports of work stress, indicating a prevalence estimate of almost half a million people who worked in the last 12 months reporting work stress at a level that was making them ill.

Just over half of the reported cases of stress, depression or anxiety reported by people who had worked in the last year were cases which the individual first became aware of within the last 12 months - some 230 000 cases (Table SWIT6W12). This gives an incidence rate of 760 cases per 100 000 people who worked in the previous year.

Looking over time, both the prevalence and incidence rate of self-reported work-related stress, depression or anxiety in people who worked in the last 12 months has remained broadly level over the period 2001/02 to 2008/09, with the exception of 2001/02 which was found to have a level that was statistically significantly higher than that of 2008/09 (Table SWIT3W12 and Table SWIT6W12).

Days lost estimates for stress, depression or anxiety have followed a similar pattern to the prevalence and incidence rates: days lost per worker have been broadly level over the period 2001/02 to 2008/09 with the exception of 2006/07 where the rate was statistically significantly higher than in 2008/09.   (see Table SWIT1).

It must be emphasized that LFS survey data is based on self-reports.  When considering changes over time in this self-reported data it should be recognised that self-reporting may be affected by many factors, such as awareness of and attitudes to stress, which may vary markedly with time (Abba et al. 2004).

The Stress and Health at Work (SHAW) study conducted in 1998 estimated that 1 in 5 of the British working population believed their job was extremely or very stressful. The more recently conducted PWC surveys estimated that 16.5% in 2004, 15.2% in 2005, 12% in 2006, 13.6% in 2007. 17.1% in 2008 and 16.7% in 2009 of British workers believed their jobs were extremely or very stressful.

Sources of data on the incidence of work-related stress and psychological disorders include the two surveillance schemes SOSMI and OPRA, representing reports of new work-related cases of mental ill-health seen by psychiatrists and occupational physicians respectively. Incidence data on work-related mental ill health reported by occupational physicians and psychiatrists for 1999-2008, are presented in Table THORP01. An estimated 1396 cases of work-related mental ill-health were seen for the first time by psychiatrists reporting to SOSMI in 2008 compared to 1,421 cases in 2007. The number of work-related mental ill-health cases seen for the first time by occupational health physicians reporting to OPRA was 3,730 in 2008 compared to 4,488 in 2007.

Taken together these schemes indicate that an estimated 5,126 new cases of work-related mental ill health occurred in Great Britain in 2008, marginally lower than the 2007 combined estimate. This figure probably significantly underestimates the true incidence of these work-related conditions in Great Britain, given that the LFS estimated that 230 000 people who worked in the past year first became aware of their work-related stress, depression or anxiety in the previous 12 months.

Analysis of trends in THOR surveillance data can be found in a report by McNamee et al (2007). This shows a mixed picture with psychiatrist reports of work-related mental health remaining fairly stable between 2000 and 2007 but with occupational physician reports showing a clear rising trend over this time period. The differences between reporting in the two schemes are complicated, but it is known that a patient would have to pass through a number of primary care filters before reaching psychiatric services (Goldberg and Huxley, 1992).