In this prospective population-based cohort study of all 98,551 individuals in Sweden who turned 65 in 2010 and had been in paid work at some point when aged 60–64, nearly half were in paid work at some point when aged 66–71. Prior SA was negatively associated with being in paid work. However, SA demonstrated somewhat different strengths of associations depending on sex and SA diagnosis group, whereas DP had similar associations with paid work irrespective of sex and DP diagnosis group (e.g., somatic DP among all 0.36; 0.34–0.39). When combining SA and DP, the ORs largely lay in-between those of the respective diagnosis groups of SA and DP alone. To the best of our knowledge, this study is the first to explore the association between specific SA and DP diagnosis groups and being in paid work after the age of 65.
Both women and men with previous SA due to mental diagnoses were less likely to be in paid work after age 65 than those with previous SA due to somatic diagnoses, which was also found when conducting analyses on the combined variable of SA and/or DP. More knowledge is warranted on possible reasons for this result, and whether this differs by type of occupation or type of mental diagnosis. It might be that the current stigma of mental disorders  decreases the likelihood of being in paid work, e.g., through hesitations to ask for relevant work adjustments. The result might also be affected by the fact that, at least in Sweden, SA spells due to mental diagnoses can last for a substantially longer time compared to SA due to most other conditions , which in itself might be a hinder for returning to work . Thus, future studies should include also information on SA duration.
SA due to somatic diagnoses when aged 60–64 was also associated with not being in paid work, however, this association was less strong than that for SA due to mental diagnoses. In Sweden, like in many other countries, mental and musculoskeletal diagnoses are the most common reason for SA . Among the musculoskeletal diagnoses, low back and neck pain are especially common , which might be a result of physically straining work conditions. Physically straining conditions, in turn, might hinder older people with somatic diagnoses to be in paid work, which could possibly be one reason for the decrease in work participation after 65. This hypothesis is supported by the result that people with lower education, who are more likely to work under physically straining conditions [45, 46], were less likely to be in paid work after 65.
At the same time, the absence of somatic SA could indicate a comparatively good work capacity among those in the older working force. Having a good work capacity might possibly imply a relatively good health status among these individuals, which in turn has been seen to predict working beyond the standard retirement age . Still, it is important to note that absence of SA does not equal absence of morbidity . Most morbidity does not affect people’s work capacity to the extent that they require SA or DP. Altogether, the results from this study indicate that somatic SA in the years leading up to the standard retirement age is associated with a lower likelihood of paid work after 65, although the association is perhaps not especially strong. These results are in line with prior research using other, broader measures of morbidity.
Surprisingly, prior SA due to both somatic and mental diagnoses did not show a significant association with being in paid work in the non-stratified analyses nor among women, whereas it was associated with a lower likelihood among men. Notably, the number of men was almost a one-third of the number of women within the group of SA due to both somatic and mental diagnoses. This surprising finding requires further research to explain. Future research could investigate to what degree the people who had previous SA in both somatic and mental diagnoses remained in paid work, whether they are in paid work for a shorter duration of time or work part-time to a greater extent, etc. Future research could also examine the duration and timing of the respective SA spells, and examine this in relation to the morbidities that underlie the SA spells.
Unsurprisingly, prior DP was a risk factor for not being in paid work after 65 among both women and men, irrespective of diagnosis group. Nevertheless, nearly 2000 individuals with DP when aged 60–64 were in paid work after 65, i.e., approximately 25% of those with prior DP. This can seem like a very high proportion, however, it must be seen in the light of that partial DP is possible in Sweden, unlike in many other countries. Thus, some of these individuals might have been on DP for, e.g., 25% of ordinary work hours, and in part-time work the rest of the time.
Especially at older ages, when different types of morbidity are more common, work adaptations can be crucial to facilitate a prolonged working life. A recent Swedish governmental inquiry on how to promote extended working lives suggested flexible work hours, reduced work hours, and the possibility to adapt work tasks based on one’s capacity . However, for those who have previously been granted DP, possibilities for work adjustments have already been assessed, and been judged as not possible.
Strengths and limitations
Strengths of this study are the prospective cohort study design, that microdata, linked at individual level from several high-quality administrative registers [48,49,50] could be used for all the people in a country who fulfilled the inclusion criteria (i.e., not a sample), the large cohort allowing for sub-group analyses, that data were not self-reported (i.e., not hampered by recall bias), that there was no non-response or drop-outs, and the long study period (12 years). Another strength is that we did not include shorter SA spells (≤14 days), which means that we only include those SA spells that led to a substantial reduction of work capacity for at least more than two weeks. Consequently, shorter, often self-certified SA spells due to, e.g., the common cold, stomach flu, or a sprained ankle were not included. Also, the SA and DP diagnoses had been assessed by the patient’s treating physician and approved by the Social Insurance Agency. Additionally, we included income from work irrespective of type of employment. This also includes self-employment, which is important as many who work beyond 65 are self-employed .
Like every study, this study has some limitations that should be taken into consideration. We had information on income from paid work, however, not on hours worked nor on type of work. There are multiple definitions of being in paid work in the literature, based on e.g., self-reported employment status, hours worked, income, registered employment [51,52,53]. Our definition was based on having had registered income from work, in order to include most individuals with some degree of paid work, as many of those who work past age 65 work part-time [18, 54]. Consequently, this study’s definition of paid work was very inclusive, which could both pose as a strength and a limitation. It does mean that several heterogeneous phenomena are captured using this outcome measure. In addition, future studies might want to differentiate analyses by levels of income or number of years with earnings when aged 66–71, and differentiate between those who remain continuously in work and those who stop working and then return.
By also including those who had income from paid work at any point when aged 60–64, we avoided the health selection that can arise from excluding those who leave work via full or part-time old-age pension before the standard retirement age of 65. Also, many continue in paid work after having taken early old-age pension and can then apply for SA. However, those who retired early were also less likely to have SA or DP during the exposure window, since some of them were at risk of SA and DP for a shorter time than those who were in paid work throughout the exposure period. However, they may still have had SA before the exposure window. This means that we might have underestimated the association between SA before age 65 and not working after age 65. Since DP is granted on a permanent basis until a person turns 65, this is less likely to be an issue regarding DP.
In addition, it should be noted that the Nagelkerke R Squares were quite low (see Tables 3 and 4), indicating that besides prior SA, DP, and the sociodemographic covariates, there were other factors that can explain work participation past the age of 65 than those accounted for in this model. Such factors could, e.g., be influence by significant others [15, 55], the employer , societal and group norms regarding retirement , work environment [22, 51], motivation to continue in paid work , personality , type of morbidity, as well as duration, rate (part- or full-time), and number of SA and DP spells. Moreover, one limitation is the possible overlap between SA and DP, which might affect the results of the analysis in which SA and DP were separate exposure variables. This is also the reason why we conducted analyses with a combined variable of SA and DP.
Further, the measures of SA and DP are also relatively crude, by bundling diagnoses together into mental respectively somatic diagnoses, and not distinguishing between part-time and full-time SA and DP or having SA or DP early or late in the study period. As a result, as with work, heterogeneous phenomena may be included in each of the groups, which may lead to an over- or underestimation of the association between SA/DP and paid work after age 65. Future studies should investigate if results vary with more specific SA and DP diagnoses, with SA/DP timing, length, and rate, as well as with e.g., specific morbidities and in specific occupations.
Still, since all individuals in Sweden fulfilling the inclusion criteria were included in this study, the results can be assumed to at least be generalizable to countries with a similar public SA, DP, and old-age pension system.