With the continuously aging global population, achieving both health and longevity among older adults is an important public health challenge. In particular, maintaining social engagement during old age is crucial for ensuring healthy aging and enhancing peoples’ well-being.^1,2) Continuing to engage in paid work is a particularly promising social commitment for this population group. In addition to the income earned, engaging in paid work provides multiple benefits for older adults, including greater social contributions, larger social networks, and more meaningful life goals, which lead to positive health benefits and overall improved well-being.³⁾

Recently, particularly in Japan, where the aging rate is the highest worldwide, an increasing number of older adults either continue or intend to return to work after retirement, despite Japan’s mandatory retirement age of 65 years.^4,5) In terms of working or not working post-retirement, a growing body of evidence has demonstrated the effects on the physical and mental health of older adults. From a traditional perspective, retirement due to old age does not necessarily have a negative effect. Some systematic reviews have suggested the positive impact of retirement on mental health.^6,7) Meanwhile, other studies have reported the positive health impacts of working post-retirement.⁸⁾ Thus, the results have been inconsistent.

Despite the contradictory results of these previous studies, the social environment of older adults is changing, such as an increasing number of individuals living alone and the weakening of their neighborhood relationships.^9,10) Thus, the meaning of post-retirement work may have changed. Therefore, further research is needed. In this context, the latest systematic review suggested the overall positive effects of people working in older age on physical and mental health.¹¹⁾ Additionally, recent studies of a large sample of older Japanese adults reported that continuing to work during old age was associated with a lower risk of mortality,¹²⁾ greater activities in daily living,¹³⁾ higher functional capacity,¹⁴⁾ healthy cognitive functioning,¹²⁾ and better mental health maintenance.¹²⁾ Furthermore, working during older age also helped to prevent the incidence of long-term care.¹⁵⁾ Therefore, as the latest evidence suggests, continuing to work during older age may be a promising approach to increasing the social engagement of this population group, which could, in turn, maintain their overall health and well-being.

Despite the increasing number of older adults continuing to work post-retirement, limited research has focused on the personal impact of their job conditions, such as employment status or working environment. A previous systematic review suggested that working post-retirement had overall positive health effects, while poor working environments and high work-related stress had negative impacts,¹¹⁾ including on physical and mental health.^16,17) Additionally, adverse health effects may occur depending on older adults’ motivation to work.¹⁸⁾ These studies highlight the need for further research on positive work-related factors to support employed older adults’ overall well-being. However, evidence is insufficient regarding these work-related factors that affect the health and well-being of working older adults. Further studies on this association are needed to promote healthy aging and maintain the well-being of older adults.

Therefore, this study examined the associations between work-related factors and happiness, a core concept of well-being, among working older adults.

The final analysis included data from 520 men and 168 women. Tables 1 and 2 show the characteristics of the male and female participants, respectively. The mean ages were 68.5±3.0 years for men and 68.0±2.6 years for women. Among the participating men, those with a higher level of happiness were more likely to have higher educational attainment, higher BMI, regular exercise habits, non-regular employment, high job strain, high job suitability, and good relationships at work; not consume alcohol or smoke; and work <5 hours daily. Among the participating women, those with a higher level of happiness were more likely to consume alcohol, have regular exercise habits, work for no more than 8 hours daily, have a high sense of job control, and feel a high sense of job suitability.

Table 3 shows the results of the analysis of associations between the examined work-related factors and participant happiness, as identified by multivariable ordinal logistic regression analysis conducted separately for men and women. After adjusting for covariates, low job suitability was negatively associated with happiness in men (OR=0.46; 95% CI, 0.28–0.78; p=0.004). In women, a daily working time of >8 hours and low job control were negatively associated with happiness (daily working time of <6 hours vs. >8 hours: OR=0.29; 95% CI, 0.12–0.71; p=0.008; low job control: OR=0.29; 95% CI, 0.12–0.72; p=0.009). These results showed similar trends in the sensitivity analysis, for which the outcomes were divided into absolute ranges (Supplementary Table S2).

The results of the analysis results after excluding self-employed participants were nearly the same as the main results (Supplementary Table S3).

This cross-sectional study examined the association between work-related factors and happiness in older adults. Our results indicated that low job suitability for men and long working hours and low job control for women were significantly and negatively associated with happiness. These findings underscore the conditions needed to promote beneficial working environments that enhance the well-being of working older adults.

Among older men, job suitability was associated with higher levels of happiness. The job suitability assessed in this study indicated that the use of work knowledge and skill sets in their work was associated with high levels of job satisfaction. In Japan, many older men regularly engage in single occupations until they reach the mandatory retirement age. Using their skills and knowledge in their older age during their retirement might increase their job satisfaction, potentially leading to higher life satisfaction. Additionally, men are more likely to seek a greater degree of professionalism and power in their workplace.²⁸⁾ Therefore, even in their retirement work, having the expertise to use their skills and knowledge might lead to happiness.

Meanwhile, among older women, job control was associated with higher happiness, while long working hours was negatively associated with happiness. The interpretation of these results is speculative; however, there are possible reasons for these findings. Many older adult women in Japan do not engage in full-time employment. Therefore, they may be more likely to search for decision-making authority in their work, such as discretion and freedom of choice in operation, when they continue to work at an older age. Alternatively, in Japan, women may engage in many tasks related to household and community matters. Therefore, non-discretionary working conditions and long working hours may interfere with domestic tasks, which might negatively affect women’s happiness.

A previous study reported the benefits of working in older age only for men, including preventing the onset of functional disability.¹³⁾ Additionally, productive activities in older age, such as paid work and volunteering, were beneficial only for men’s mental health.²⁹⁾ These findings imply the presence of sex differences in the impact of working status among older adults. In Japanese society, the role of paid work likely differs between men and women because the latter are relatively more likely to also have a social role outside their employment, such as housework or various community social involvements.

Meanwhile, the sex differences in work-related factors of happiness might be influenced by employment status between men and women. Unlike men, self-employed cases were relatively low in women participants. However, our preliminary analysis that excluded self-employed respondents showed results that were highly similar to those of the main analysis. We presume that the work-related factors associated with happiness differ by sex and not by employment type. Therefore, when promoting increased employment for older adults, a given social system needs to carefully consider the quality of working conditions, in addition to the different job needs of men and women.

As the Japanese population ages, the number of older adults who continue to work after retirement will continue to increase.^6,8) Our results provide information on how to structure working environments for employed older adults to enhance their overall health and happiness. However, despite the growing evidence that working in later years can benefit overall health and happiness, it might also have negative consequences.^11,16,17) In addition to previous knowledge, our findings contribute to the promotion of the employment of older adults by identifying work-related factors that may be detrimental to happiness in this population group. The results of the present study highlight the need to consider the suitability of the job, create friendly working conditions, and make appropriate changes to the working environment when promoting increased employment of older adults. Further evidence is needed to promote the employment of older adults, including more detailed studies of working conditions and environments.

This study has certain limitations. First, the cross-sectional design prevented our determination of the causality of the investigated work-related factors on participants’ happiness. Therefore, further investigation using longitudinal data is required. Second, we had no information about participants’ economic status, such as income or overall wealth. These variables may have resulted in residual confounding factors. Third, we had no detailed information about the nature of the participants’ jobs (for instance, employment in blue- or white-collar jobs). This information is important to note because the relationship between work-related factors and happiness may differ depending on the nature of the job. Fourth, we had no information on existing or potential mental illnesses, including depression. Mental illness is an important determinant of happiness, which may result in a bias in our results. Fifth, this study recruited only those individuals who had received annual health check-ups at a public health center. In addition, the response rate of the participants to the study recruitment was low (25.9%). Therefore, the backgrounds of the study participants may differ from those of typical older workers in this area. Our sample might have been more health-conscious and had a higher socioeconomic status compared to those of the average worker. This limitation may have resulted in a selection bias. Finally, we recruited participants from only one public health center in a suburban area of Japan. The types and conditions of work may have characteristics unique to this area. Therefore, the generalizability of our results may be limited and future studies using a nationwide sample are required.

In conclusion, the results of the present study showed that low job suitability in men, as well as long daily working time and low job control in women, were significantly and negatively associated with happiness among older working adults. These findings underscore the need to improve the working conditions of this population group to enhance their overall health and well-being.