Risk factors in long-term sickness absence
In recent years, sickness absence and the possibilities to reduce its incidence has been high on the policy agenda in Denmark. A study carried out by the Ministry of Employment into the causes of sickness absence concluded that physical factors, low skill discretion, low decision-making powers and poor quality of management all increase the likelihood of sickness absence among workers. Most interestingly, it appears that the combined effects of exposure to some physical risks and poor quality of management have had a huge impact on sickness absence levels to date.
Background to study
In recent years, increasing attention has been directed towards the incidence of sickness absence in Denmark. For example, the Ministry of Employment (Beskæftigelsesministeriet) has calculated that about 142,000 Danish employees per annum take sickness leave. In light of this fact, the ministry stresses the potential benefits of reducing the level of sickness absence in terms of increasing productivity levels and improving the well-being of employees. In this context, research is being conducted at the National Institute of Occupational Health (Arbejdsmiljøinstituttet) on the causal determinants of sickness absence and exclusion and on how to retain people in work. Recently, the institute published a study on ‘Work environment factors associated with long-term sickness absence and return to work’ (444Kb PDF).
Main study findings
The study reveals that 40% of total sickness absence is explained by differences in levels of exposure to work environment factors. Moreover, and quite surprisingly, as few as 20% of the employees surveyed who have been on sickness leave accounted for 80% of the total number of sickness absence days.
However, the study data reveal that there are considerable differences in the factors determining sickness absence due to the length of absence periods.
The study finds that exposure to the factors presented in Table 1 are characteristic for employees reporting above average numbers of sickness absence days. Three physical and two psychosocial work environment factors, in particular, seem to have a significant impact on the number of sickness absence days reported. Moreover, a high body mass index (BMI) and propensity to smoke are also associated with the level of sickness absence; levels of absence are also higher among both female and older employees (data not shown).
Furthermore, employees working in the public sector show a higher rate of sickness absence than other employees. In addition, there is an indication that employees on sickness leave consider they are less efficient compared with employees at work.
Different results emerge when isolating employees with longer periods of sickness absence and taking their return to work into account.
|Arms lifted/hands twisted||1.3|
|Monotonous, repetitive work||1.23|
|Low skill discretion||1.23|
|Low decision–making powers||1.23|
|Sick-listed at baseline||Mean = 75.1|
|Working at baseline||Mean = 82.9|
Notes: * Odds ratio: expresses the ratio of the odds of an event occurring in one group to the odds of it occurring in another group (in this case: high level of sickness absence to the average level of sickness absence). An odds ratio higher than 1 indicates that the condition or event is more likely in the first group. Only statistically significant differences are shown.
Source: Labriola, M., Work environment factors associated with long-term sickness absence and return to work, National Institute of Occupational Health, Copenhagen, 2006
Long-term sickness absence and return to work
In the study, long-term sickness absence is defined as a period of at least eight consecutive weeks of absence. In the research on long-term sickness absence, data allowed for analysis of such absence both at individual and workplace levels (Table 2).
At the individual level, no associations between psychosocial risk factors and long-term absence can be observed. However, when combined with workplace level, the data show associations between long-term sickness absence and low decision-making power, as well as a low level of supervisor support and poor management. More interestingly, the study finds that poor management increases the negative impacts of other work environment risk factors on sickness absence. For example, employees exposed to poor management and heavy lifting face twice the risk of absence from work than employees exposed to a high quality of management and heavy lifting.
Even though psychosocial risk factors prove to have no impact on long-term sickness absence at individual level, they do appear to have an effect on whether an employee returns to work: a low job profile and low decision-making powers in the job appear to have an impact on whether an employee experiencing long-term sickness absence will actually return to work.
|Bending/twisting of neck or back||1.33|
|Pushing/pulling heavy loads||1.15|
|Physical activity in work||1.43|
|Low decision-making powers||2.17|
|Low supervisor support||2.04|
|Low management quality||1.75|
|Twisting the back/Low management quality||2.94|
|Pushing or pulling heavy loads/Low management quality||3.08|
|Lifting/Low management quality||3.82|
|Physical activity at work/Low management quality||3.22|
Notes: * See explanatory note for odds ratio in Table 1.
Source: Labriola, M., 2006
Employees exposed to long-term sickness absence
Analysis was also performed on the demographics, jobs and sectors of employees affected by sickness absence. The study shows that female employees, as well as employees aged 40–49 years and those with only lower secondary school education, are at a greater risk of experiencing long-term sickness absence. Moreover, the following groups of workers carry a greater risk of absence from work:
- childcare workers and pre-school teachers;
- healthcare workers;
- kitchen staff;
- unskilled workers.
Having a job in any one of these categories, working in the public sector, or working in the healthcare or social work sectors are factors which carry a significantly higher risk of experiencing long-term sickness absence.
In comparison, managers, computer professionals, technicians, designers, and highly-educated professionals show a significantly lower than average risk of long-term sickness absence.
Rune Holm Christiansen and Helle Ourø Nielsen, Oxford Research