Sickness absence with psychiatric diagnoses: Individual and contextual predictors of permanent disability
Introduction
Long-term sickness absence due to mental health problems or disorders is probably increasing in Western Europe (Moncrieff and Pomerleau, 2000; Knapp, 2003; Jarvisalo et al., 2005; Henderson et al., 2005; Hensing et al., 2006). However, sickness absence benefit schemes vary, and comparison between countries may be difficult. Sickness absence is an indicator of the functional consequences of diseases (Marmot et al., 1995; Norman and Bambra, 2007), and such data can supplement self-reported data from classic epidemiological surveys of the prevalence of mental health disorders (Broadhead et al., 1990; Judd et al., 1996; Kessler and Frank, 1997; Kringlen et al., 2001). In the Nordic countries, tax-based social insurance is universal, covering all vocationally active inhabitants, and therefore population-based studies using social insurance data are feasible.
The literature on sickness absence and disability pension (DP) due to mental health problems has recently been reviewed (Hensing and Wahlstrom, 2004). A female/male prevalence gradient of approximately 2:1 is observed in most studies. This corresponds to the gender differences in the incidence of common mental disorders (Piccinelli and Wilkinson, 2000; Kringlen et al., 2001; Stordal et al., 2001; Angst et al., 2002; Bijl et al., 2002). However, studies from Sweden (Hensing et al., 1996) and Norway (Hensing et al., 2000) have shown that spells of sick leave with psychiatric diagnoses tend to be longer among men. The risk of permanent occupational disability after psychiatric sickness absence is probably also higher for men than women, compared to men with other diagnoses (Gjesdal and Bratberg, 2003; Gjesdal et al., 2004, Gjesdal et al., 2008). A higher threshold among men for reporting mental health problems and for taking sick leave has been suggested, but this is controversial (Roness et al., 2005). A higher incidence of serious mental illness and alcohol dependence among men is another possible explanation.
Socioeconomic deprivation predicts major psychiatric disorders at individual level (Muntaner et al., 2004; Kivimaki et al., 2007), whereas the findings for “common mental disorders” are more mixed (Weich and Lewis, 1998a, Weich and Lewis, 1998b; Lahelma et al., 2006; Skapinakis, 2007).
A growing literature has also analysed how contextual and geographic factors influence mental health. Several contextual levels have been examined: households (Weich et al., 2003, Weich et al., 2005; Sundquist and Ahlen, 2006), neighbourhoods (Sundquist and Ahlen, 2006), electoral wards (Croudace et al., 2000; Weich et al., 2003, Weich et al., 2005; Fone et al., 2007a, Fone et al., 2007b), and other small areas (Sytema, 1991; Fone et al., 2007c). Similar investigations have also been carried out in larger areas like local authority districts (Skapinakis et al., 2005) or regions of the UK (Lewis and Booth, 1992; Weich et al., 2001), or states in the US (Kennedy et al., 1998; Edlund et al., 2006). In these studies outcome measures have also varied: rates of psychiatric admissions (Sytema, 1991; Croudace et al., 2000; Edlund et al., 2006; Sundquist and Ahlen, 2006), incidence of psychoses (Croudace et al., 2000), and prevalence of “common mental disorders” (Weich et al., 2003; Skapinakis et al., 2005; Fone et al., 2007a, Fone et al., 2007b, Fone et al., 2007c). Overall, most studies have found that geographical variations are marginal when fully adjusted for individual factors. However, people living in urban areas might have a higher prevalence of mental health problems, compared to those living in more rural areas (Paykel et al., 2003; Weich et al., 2006). A recent study from Norway found that the prevalence of DP with mental health diagnoses was highest in semi-rural areas (Andersson et al., 2006).
In the UK several indices have been constructed to measure deprivation on a contextual level (Jarman, 1984; Carstairs and Morris, 1991; Townsend et al., 1988), and in addition similar indices have been constructed to specifically predict the need for mental health services in geographic areas (Croudace et al., 2000; Fone et al., 2007a, Fone et al., 2007c).
Despite the fact that the Nordic countries have universal schemes for sickness absence benefits and DP (Box 1), there are unexplained geographical variations in sickness absence rates and numbers of DP recipients (Knutsson and Goine, 1998; Norwegian Social Insurance Services, 2000). In the 19 Norwegian counties, the mean number of sick days compensated by the Norwegian Social Insurance Services (NIS) in 1997 varied between 7.2 and 11.2 days. In the same year, the proportion of disability pensioners among the population aged 16–66 varied between 6% and 11.1% (Norwegian Social Insurance Services, 1998).
Contextual explanations for a higher consumption of social insurance benefits might include factors such as level of unemployment, economic prosperity, population health status, and availability of health services. Finally, compositional effects of individual factors, such as age, education, earnings, or morbidity figures, may also cause variations among geographical and administrative entities like counties. Plant downsizing in Norway has been found to increase the sickness absence entry rate of workers in affected plants (Rege et al., 2008), and decreased demand for low-skilled labour seems to increase disability entrance in the US (Autor and Duggan, 2003). Furthermore, a high use of social insurance benefits at baseline might predict higher consumption in the future, reflecting differing attitudes in the population and/or different practices of local departments of social insurance services. A recent study found that DP risk was affected by the DP entry rate in the neighbourhood (Rege et al., 2007), and a previous Norwegian study has shown that deprived municipalities have higher rates of disability pensioning, after adjustment for individual predictors (Krokstad et al., 2004). In the UK, too, levels of incapacity benefits in local government districts probably have a strong relationship with all-cause mortality and census measures of morbidity (Bambra and Norman, 2006) as well as with the mental health status of the population (Fone et al., 2007b).
The aims of the current study were (1) to assess the cumulative incidence of long-term sickness absence with psychiatric diagnoses in Norwegian counties in 1997 and (2) to identify contextual and individual predictors of the further transition to permanent DP status using a multi-level statistical approach.
Section snippets
Setting and participants
A prospective population-based study covering all vocationally active Norwegian women and men was carried out between 1997 and 2002. On 1 January 1997, a total of 979,301 men and 886,503 women were vocationally active (employed or registered unemployed) in Norway and were therefore covered by the national sickness absence benefit scheme. During 1997, all cases of at least 8 weeks’ sickness absence were recorded by the NIS. Cases with a mental diagnosis on the 8 weeks’ sickness certificate were
Long-term sickness absence and transition to disability pension
For 1997, a total of 7099 men (7.2/1000 at risk) and 12,380 women (14.0/1000) had at least one spell of more than 8 weeks’ sickness absence with a psychiatric diagnosis. Table 1 also shows the distribution of the individual-level variables among the study sample. Among women, depression was the largest subgroup with 73% of cases compared to 61% among men, whereas alcohol and substance use disorders and psychoses were more frequent among the men. Cases with psychiatric diagnoses made up 15.1% of
Main results
We found strong effects of individual-level variables on the risk of becoming a disability pensioner after sickness absence with a diagnosis of mental illness: gender, diagnosis, higher age, lower education, and lower earnings. Overall, men had a higher risk of becoming a disability pensioner after sickness absence with a diagnosis of mental illness. The cases with depression had the best prognosis in both genders, except for the 5% of cases diagnosed with stress reaction (ICPC P02). Low
Conclusions
In addition to individual determinants, transition from long-term sickness absence to DP due to a mental health problem was marginally influenced by the relative social deprivation at the county level for women but not for men. Clearly, there is a lot more to learn about contextual influence on social insurance utilisation. Macro-level determinants are important when trying to explain temporal variations in the levels of benefits, whereas micro-level determinants pertain to individual risk. For
References (68)
- et al.
What is the association between sickness absence, mortality and morbidity?
Health and Place
(2006) - et al.
Places, people and mental health: a multilevel analysis of economic inactivity
Social Science and Medicine
(2007) - et al.
Occupation and unemployment rates as predictors of long term sickness absence in two Swedish counties
Social Science and Medicine
(1998) - et al.
Multiple measures of socioeconomic circumstances and common mental disorders
Social Science and Medicine
(2006) - et al.
Sickness absence for psychiatric illness: the Whitehall II Study
Social Science and Medicine
(1995) - et al.
Neighbourhood income and mental health: a multilevel follow-up study of psychiatric hospital admissions among 4.5 million women and men
Health and Place
(2006) - et al.
Removing the health domain from the Index of Multiple Deprivation 2004—effect on measured inequalities in census measure of health
Journal of Public Health
(2006) Practical Statistics for Medical Research
(1991)- et al.
Disability pension for psychiatric disorders: regional differences in Norway 1988–2000
Nordic Journal of Psychiatry
(2006) - et al.
Gender differences in depression. Epidemiological findings from the European DEPRES I and II studies
European Archives of Psychiatry and Clinical Neuroscience
(2002)