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 the surveys of Self-reported Work-related Illness (SWI), 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 and 2007. Alternatively, the SWI interviewer-administered surveys collected self-reports on ill health attributed to work-related stress. The simple self-reported data from these SWI surveys provides the best estimate of the overall prevalence of work-related stress in Britain, but has limitations regarding assessment of temporal trends.

All eight SWI surveys indicates that stress and related conditions formed the second most commonly reported group of work-related ill-health conditions after musculoskeletal disorders. SWI06/07 estimated that work-related stress, depression or anxiety affected 530 000 people in Great Britain (Table SWIT3), with an estimated 13.8 million lost working days due to these work-related conditions in Britain in 2006/07 (Table SWIT1). This represents an estimated average of 30.2 working days lost per year per affected case and makes stress, depression or anxiety one of the largest contributors to the overall estimated annual days lost from work-related ill-health in SWI06/07. Of the estimated 530 000 persons affected with work-related stress, depression or anxiety, an estimated 245 000 first became aware of their condition within the last 12 months (Table SWIT6E). A further estimated 60 000 people reported work-related heart disease (Table SWIT3). Evidence from SWI95 suggests most of those reporting work-related heart disease ascribed its cause to work stress. Consequently most of these estimated 63 000 may also represent indirect reports of work stress, indicating a prevalence estimate of around half a million people reporting work stress at a level that was making them ill.

The results from the SWI surveys are not directly comparable, but the best available comparable estimates across these studies suggest that the prevalence rate of self-reported work-related stress and related conditions approximately doubled between SWI90 and SWI98/99 (see Historical picture 1990’s). Since then prevalence remained at around SWI98/99 levels in SWI01/02, SWI03/04 and SWI04/05, but has fluctuated since (see Historical picture on ill health). Comparison of incidence are more problematic than prevalence in earlier surveys as data on incidence for SWI90 and SWI99/00 are not available. However, the data indicate an increase in the incidence rate between SWI95 and SWI01/02. Subsequently there was no change in incidence rate between SWI01/02, SWI03/04 and SWI04/05, with a fall between SWI04/05 and SWI05/06 followed by a rise in SWI06/07 back to incident rates of the same order as 2002/01 (Table SWIT6W12).

Days lost estimates are available from SWI95, SWI01/02, SWI03/04, SWI04/05 , SWI05/06 and SWI06/07. Comparisons suggest that the days lost attributed to stress and related conditions rose between SWI95 and SWI01/02, due in part to an increase in the average days lost per case (as shown in Table SWIT1). However, since then the total days lost estimate has followed a similar pattern to the incidence. It was of the same order from 2001/02 to 2004/05, fell between 2004/05 and 2005/06, then rose back to levels of a similar order to that in  2001/02 in SWI06/07. However, the average days lost per case attributed to work-related stress, depression or anxiety was of the same order from 2001/2 to 2006/7 (see Table SWIT1). It must be emphasized that any comparisons between SWI surveys, even when data are made as comparable as possible, have limitations in respect of assessing trends, due to differences in design and reliance on the simple self-reporting of stress. Indeed, simple self-reporting of stress 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, and 13.6% in 2007 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 for 1999-2006, and by psychiatrists for 1999-2006, are presented in Table THORP01. An estimated 1975 cases of work-related mental ill-health were seen for the first time by psychiatrists reporting to SOSMI in 2006 compared to 2223 cases in 2005. The number of work-related mental ill-health cases seen for the first time by occupational health physicians reporting to OPRA was 3904 in 2006 compared to 4173 in 2005.

Taken together these schemes indicate that an estimated 5879 new cases of work-related mental ill health occurred in Great Britain in 2006, lower than the 2005 combined estimate. This figure probably significantly underestimates the true incidence of these work-related conditions in Great Britain, given that SWI06/07 estimated that 245 000 people first became aware of their work-related stress, depression or anxiety in the previous 12 months.

Trends in THOR surveillance data show a mixed picture with a falling trend in psychiatrist reports of work-related mental health between 1999 and 2006 but with occupational physician reports rising between 1999 and 2001 and then remaining steady. The reasons for the earlier different pattern between specialists are unclear. However, 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). It is possible that the nature of, or pressures on, that filtering system changed resulting in proportionately fewer cases reaching psychiatrists and a subsequent rise in cases seen by occupational physicians.