Older Adult Males Who Worked at Small-Sized Workplaces Have an Increased Risk of Decline in Instrumental Activities of Daily Living: A Community-Based Prospective Study

Occupational status and self-reported low back pain by gender: a nation-wide cross-sectional study among the general population in Japan

Background

We aimed to examine the cross-sectional association between occupational class and self-reported low back pain (LBP) in a representative sample of the Japanese general population.

Methods

We used anonymized data from a nationwide survey (31,443 men and 35,870 women aged ≥ 20). Occupational class variables included working status, occupation, employment status, and company size (number of employees). Covariates included age, socio-economic status, lifestyle, and comorbidities. Poisson regression models stratified by gender were used to estimate adjusted prevalence ratio (APR) and 95% confidence interval (CI) for self-reported LBP.

Results

The prevalence of self-reported LBP was 11.7% in men and 14.2% in women. After adjustment for covariates and mutual adjustment for all occupational class variables, among both genders, agricultural/forestry/fishery workers and non-workers had a significantly higher prevalence of self-reported LBP: APR (95% CI) of agricultural/forestry/fishery was 1.36 (1.08–1.70) in men and 1.59 (1.30–1.93) in women; that of non-workers was 1.42 (1.18–1.70) in men and 1.23 (1.08–1.40) in women. Among men, non-regular employees were more likely to have self-reported LBP than regular employees: APR (95% CI) was 1.25 (1.07–1.46) in part-timers and casual staff and 1.18 (1.03–1.35) in other types of non-regular employees. Moreover, compared to men working at companies with ≥ 100 employees, men working at companies with 30–99 employees had a significantly higher prevalence of self-reported LBP (APR 1.17; 95% CI, 1.03–1.34). Among women, professionals and technicians (1.26; 1.11–1.43) and sales workers (1.22; 1.04–1.43) had a significantly higher prevalence of self-reported LBP than clerks. Neither employment status nor company size was associated with self-reported LBP in women. After stratified analyses by age group, similar patterns were observed in participants aged 20–64, but not in those aged ≥ 65.

Conclusion

Our results suggest that self-reported LBP is highly prevalent among agricultural/forestry/fishery workers and the unemployed, regardless of gender, and that there are also gender differences in the association of occupational class factors with self-reported LBP. It is necessary, therefore, to take preventive measures against LBP based on gender and occupational class factors in Japan.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12199-021-01031-2.

Social participation and mortality according to company size of the longest-held job among older men in Japan: A 6-year follow-up study from the JAGES

OBJECTIVES

The purpose of this study was to examine the relationship between social participation (type/pattern) and mortality according to company size of the longest-held job among older men in Japan who have worked in the company.

METHODS

Longitudinal data from the Japan Gerontological Evaluation Study were used in this study. Functionally independent individuals aged 65 years and older in Japan were surveyed. Work and community organizations (local community, hobbies, and sports) were used as social participation. A Cox proportional hazards model was used to calculate mortality hazard ratios.

RESULTS

Analysis was carried out on 19 260 participants. A total of 2870 deaths occurred during the 6-year follow-up period. Those in companies with 49 or fewer employees had the highest prevalence of work participation and the lowest participation in any community organization. Regardless of company size, the mortality risk was significantly lower for participants in any social participation (eg, the hazard ratio for participation in a hobby organization among those with a company size of 49 employees or fewer was 0.74, 95% CI: 0.65-0.85) compared to nonparticipants whose company size was 49 or fewer employees.

CONCLUSIONS

In Japan, although older men who have worked for small companies may have fewer benefits, their social participation may reduce their mortality risks. To avoid increasing health inequalities, it is necessary to create an environment in which they are more likely to participate in social activities.

Longitudinal association between lifetime workforce participation and risk of self-reported cognitive decline in community-dwelling older adults

BACKGROUND

Although many governments are promoting workforce participation (WP) by older people, evidence of WP's effects on active aging is inadequate. We examined whether there is a gender-specific beneficial effect of lifetime WP from adulthood though old age against self-reported cognitive decline (CD) among community-dwelling older adults.

METHODS

We used data from a community-based prospective study of 2,422 men and 2,852 women aged ≥65 with neither poor cognition nor disability in basic activities of daily living at baseline. Self-reported CD was measured using the Cognitive Performance Scale. Lifetime WP evaluated the presence or absence of WP at baseline, the longest-held occupation, and lifetime working years (total working years throughout lifetime). Generalized estimating equations of the multivariable Poisson regression model were applied to evaluate a cumulative incidence ratio (CIR) for self-reported CD and a 95% confidence interval (CI), controlled for age, education, self-perceived economic status, chronic medical conditions, smoking history, physical activity, depression, and instrumental activities of daily living. To examine any gender-specific association, stratified analyses by gender were performed.

RESULTS

The 33-month cumulative incidence of self-reported CD was 15.7% in men and 14.4% in women. After covariate adjustments and mutual adjustment for three items of lifetime WP, men who had their longest held job in a white-collar occupation reported significantly decreased self-reported CD compared to men engaged in blue-collar jobs (CIR 0.72; 95% CI, 0.57-0.91), and women had a significant dose-response relationship between longer lifetime working years and less decline in subjective cognitive functioning (P for trend <0.029). Among both genders, WP at baseline was not associated with self-reported CD.

CONCLUSIONS

Our results suggest that lifetime WP, especially lifetime principal occupation in men and lifetime working years in women, may play a more prominent role in preventing self-reported CD than later-life WP.

Size of company of the longest-held job and mortality in older Japanese adults: A 6-year follow-up study from the Japan Gerontological Evaluation Study

OBJECTIVES

Very few longitudinal studies have investigated the question of whether differences in company size may give rise to health inequalities. The aim of this study was to examine the relationship between company size of the longest-held job and mortality in older Japanese adults.

METHODS

This study used longitudinal data from the Japan Gerontological Evaluation Study. Surveys were sent to functionally independent individuals aged 65 or older who were randomly sampled from 13 municipalities in Japan. Respondents were followed for a maximum of 6.6 years. The Cox proportional hazards model was used to calculate mortality hazard ratios (HRs) for men and for women. Analysis was carried out on 35 418 participants (197 514 person-years).

RESULTS

A total of 3935 deaths occurred during the 6-year follow-up period. Among men, in Model 1 that adjusted for age, educational attainment, type of longest-held job, and municipalities, mortality HRs decreased significantly with increasing size of company (P for trend = .002). Compared to companies with 1-9 employees, the mortality HR (0.78, 95% confidence interval: 0.68-0.90) was significantly lower for companies with 10 000 or more employees. However, there were no significant differences among women (P for trend = .41).

CONCLUSIONS

In men, mortality in old age may decrease with increasing size of company of the longest-held job. To reduce health inequalities in old age due to differences in size of company, studies should be conducted to determine the underlying mechanisms and moderating factors and those findings should be reflected in labor policies and occupational health systems.

The Association Between Education and Smoking Prevalence, Independent of Occupation: A Nationally Representative Survey in Japan

Background

Higher smoking prevalence in less educated persons and manual workers is well known. This study examines the independent relationship of education and occupation with tobacco use.

Methods

We used anonymized data from a nationwide population survey (30,617 men and 33,934 women). Education was divided into junior high school, high school, or university attainment. Occupation was grouped into upper non-manual, lower non-manual, and manual. Poisson regression models stratified by age and gender were used to estimate adjusted prevalence ratio (PR) and 95% confidence interval (CI) for current smoking.

Results

After adjustment for covariates, education, and occupation, education was significantly related to current smoking in both genders; compared to university graduates, PRs of junior high school graduates aged 20–39, 40–64, and ≥65 were 1.74 (95% CI, 1.53–1.98), 1.50 (95% CI, 1.36–1.65), and 1.28 (95% CI, 1.08–1.50) among men, and 3.54 (95% CI, 2.92–4.30), 2.72 (95% CI, 2.29–3.23), and 1.74 (95% CI, 1.14–2.66) among women, respectively. However, significantly higher smoking prevalence in manual than in upper non-manual was found only in men aged 20–64; compared to upper non-manual, the PRs of manual workers aged 20–39, 40–64, and ≥65 were 1.11 (95% CI, 1.02–1.22), 1.18 (95% CI, 1.10–1.27), and 1.10 (95% CI, 0.89–1.37) among men, and 0.95 (95% CI, 0.75–1.20), 0.92 (95% CI, 0.75–1.12), and 0.46 (95% CI, 0.22–0.95) among women, respectively.

Conclusions

Independent of occupation, educational disparities in smoking existed, regardless of age and gender. Occupation-smoking relationship varied with age and gender. Our study suggests that we should pay attention to social inequality in smoking as well as national smoking prevalence.

The differential effects of type and frequency of social participation on IADL declines of older people

BACKGROUND

Although social participation (SP) is valid in active aging, it is vague which types and the frequency of SP are effective in maintaining instrumental activities of daily living (IADL). We conducted a community-based prospective cohort study and investigated the association of the types and frequency for SP with IADL decline in community-dwelling older adults.

METHODS

The target population were all individuals aged ≥65 living in a commuter town in Nara, Japan. A total of 6,013 participants with independent IADL at baseline were analyzed. IADL was assessed using the Tokyo Metropolitan Institute of Gerontology Index of Competence. Six SP types were assessed: volunteer groups, sports groups, hobby clubs, senior citizens' clubs, neighborhood community associations, and cultural clubs. The frequency of SP was categorized into frequent (i.e., weekly or more), moderate (i.e., monthly or yearly), and non-participation. Using multiple logistic regression models, the odds ratio (OR) and a 95% confidence interval (CI) for IADL decline were calculated. Covariates included age, marital status, education, subjective economic status, work status, body mass index, chronic medical conditions (i.e., hypertension, diabetes mellitus, heart disease, and cerebrovascular disease), lifestyle factors (i.e., alcohol, smoking, and exercise), self-rated health, depression, and cognitive functioning. To examine gender differences, stratified analyses by gender were performed.

RESULTS

During the 33-month follow-up, 16.4% of men and 8.7% of women exhibited IADL decline. After adjustment for all covariates, compared to those who never participated, women with moderate participation had significantly lower odds of IADL decline in volunteer groups (OR = 0.53, 95% CI = 0.31-0.88), hobby clubs (OR = 0.55, 95% CI = 0.38-0.79), neighborhood community associations (OR = 0.58, 95% CI = 0.42-0.81), and cultural clubs (OR = 0.51, 95% CI = 0.31-0.82), and women with frequent participation had lower odds of IADL decline in hobby clubs (OR = 0.63, 95% CI = 0.43-0.93). In contrast, among men, the significant association between SP and less risk of IADL decline was limited to moderate participation in neighborhood community associations (OR = 0.79, 95% CI = 0.63-0.99), and there were no differences between frequent participation and non-participation in all types of SP. Regarding volunteer groups, compared to women with frequent participation, women with moderate participation had a significantly lower risk of IADL decline (OR = 0.37, 95% CI = 0.18-0.77). The results of additional stratified analyses by self-rated health, depression, and cognitive functioning showed that the associations of the type and frequency of SP with IADL decline varied according to physical and mental functioning.

CONCLUSIONS

Several types of SP have a favorable effect on IADL through moderate participation rather than frequent participation, and women with moderate participation in volunteer groups have a more beneficial effect on IADL than women with frequent participation. When advising community-dwelling older adults on SP for IADL maintenance, health professionals may need to take into account plateau effects, gender differences, and physical and mental functioning.