Trajectories of marginal part-time work and risk of depression. Does job or income insecurity mediate the relation?

OBJECTIVES: Working few hours a week, known as marginal part-time work, may increase both job and income insecurity, which have been linked to the risk of depression. This study examines the association between marginal part-time work and depression and the mediating role of job and income insecurity. METHODS: We included 30 523 respondents of the Danish Labor Force Survey (DLFS) between 2010 and 2017 and linked them to register-based information on weekly working hours, which was used to identify full-time workers and model group-based trajectories of marginal part-time. These data were linked with survey information on job and income insecurity, and register-based information on hospital-diagnosed depression or redeemed anti-depressant drugs in the following two years. We estimated hazard ratios (HR) by Cox proportional hazards models and conducted mediation analyses to estimate the natural direct and indirect effects using job and income insecurity as mediators. RESULTS: We identified three distinct trajectories of marginal part-time work: constant marginal part-time work, mobile towards marginal part-time work, and fluctuating in and out of marginal part-time work. Compared with full-time workers, the constant [HR 2.42, 95% confidence interval (CI) 1.83-3.20], mobile (HR 2.84, 95% CI 2.16-3.75), and fluctuating (HR 3.51, 95% CI 2.07-5.97) trajectories all had higher risks of depression. There was no evidence of mediation by either job (HR 1.02, 95% CI 0.92-1.12) or income (HR 0.98, 95% CI 0.89-1.08) insecurity. CONCLUSIONS: We found a higher risk of depression following marginal part-time work. The higher risk was not mediated by job or income insecurity.

Night and evening shifts and risk of calling in sick within the next two days - a case-crossover study design based on day-to-day payroll data.

OBJECTIVE: Night and evening work is associated with risk of sickness absence, but little is known about the acute effects of these types of shifts on sickness absence. The aim of the current study is therefore to examine the risk of calling in sick within two days after a night or an evening shift. METHODS: By use of a case-crossover design, odds of calling in sick within two days after a night or an evening shift compared to day shifts were analyzed within the same person. Day-to-day information on shifts and sickness absence were derived from the Danish Working Hour Database on 44 767 cases. Data were analyzed using conditional logistic regression. The analyses were supplemented by extensive testing of methodological choices. RESULTS: Analyses showed higher odds of calling in sick after a night shift [odds ratio (OR) 1.22, 95% confidence intervak (CI) 1.14-1.30] and lower odds after an evening shift (OR 0.89, 95% CI 0.84-0.93) compared to day shifts within the same person. Testing of methodological choices suggested that in particular the duration of case and control periods, time between these periods along with the number of control periods affected the results. CONCLUSION: This large and unique within-person study among Danish hospital employees indicate that the risk of calling in sick is affected by the types of shifts, independently of sex, age, and time-invariant confounding. Extensive testing identified important methodological choices eg, length and number of included periods to consider when choosing the case-crossover design.

Self-Reported Sleepiness after 2, 4, and 7 Consecutive Night Shifts and Recovery Days in Danish Police Officers.

BACKGROUND: Night shift work often implies shorter sleep duration and this can lead to sleepiness, which has been associated with an increased risk of accidents and injuries. The aim is to study how the number of consecutive night shifts affects self-reported sleepiness. PARTICIPANTS AND METHODS: The study was a quasi-experimental, within-subject crossover study with 73 police officers. Three work schedules of two, four, and seven consecutive night shifts followed by the same number of recovery days, i.e., days worked or days off, was performed by all participants. Sleepiness was self-reported using the Karolinska sleepiness scale (KSS) every fourth hour on the last night shift and the last recovery day in each sequence. RESULTS: We observed differences in the level of sleepiness between recovery days and night shift days but no differences in the pattern of sleepiness levels on night shift days in the different work schedules. The highest levels of KSS were observed before bedtime (at 07:00 after a night shift and 23:00 on a recovery day). CONCLUSION: The number of consecutive night shifts did not affect the self-reported levels of self-reported sleepiness among Danish police officers.

Leadership behaviours and health-related early exit from employment: a prospective cohort study of 55 364 employees.

BACKGROUND: Absence of certain leadership behaviours, such as lack of feedback, recognition and involvement in employee development, has been associated with long-term sickness absence. We tested the hypothesis that absence of eight specific behaviours predicts health-related early exit from employment, and investigated differential effects in subgroups to guide future preventive initiatives. METHODS: Using Cox-proportional hazard modelling, we examined the prospective association between absence of leadership behaviours and health-related early exit from employment in a sample of 55 364 employees during 4.3 years follow-up. Leadership behaviours were measured by employee ratings in national surveys from 2012 to 2016. Exit from employment included disability pension and related measures of health-related early exit, retrieved from a national registry. RESULTS: We identified 510 cases of health-related early exit from employment during follow-up. A high level of absence of leadership behaviours, was associated with an increased risk of exit from employment (hazard ratio: 1.57, 95% CI: 1.31; 1.89). Subgroup analyses showed that the association between absence of leadership behaviours and exit from employment was similar for women and men and across age groups. The association was stronger for employees with high level of education than for employees with medium/low education, and the association was not observed among employees with a prevalent depressive disorder. CONCLUSIONS: Absence of the eight leadership behaviours is a risk factor for health-related early exit from employment in the Danish workforce. More studies are needed to confirm the results.

Labor Market Affiliation of Marginal Part-Time Workers in Denmark-A Longitudinal Study.

This longitudinal study examined the labor market affiliations of marginal part-time workers (<15 working hours/week) compared with full-time workers (32−40 working hours/week) within gender and age groups. Analyses were based on 1,492,187 Danish employees with marginal part-time or full-time work at baseline using register data of working hours and labor market affiliation from the Labor Market Account. We used the Expected Labor Market Affiliation method within gender and age groups to estimate the time spent in different labor market states over a 5-year follow-up from 2012−2017. The multistate model included five recurrent labor market states: work, unemployment, long-term sickness absence, studying, and temporarily out, and the results were adjusted for education level, morbidity, and ethnicity. A marginal part-time worker generally had fewer days of work without social benefits and spent more days studying during follow-up compared with a full-time worker. In addition, marginal part-time workers ≥ 25 years old had more days of unemployment and more days of long-term sickness absence. These findings suggest that marginal part-time workers have fewer paid workdays without social benefits compared with full-time workers, depending on age. Further studies should explore whether marginal part-time work is a stepping stone into or out of the labor market.

A comparison of work environment, job insecurity, and health between marginal part-time workers and full-time workers in Denmark using pooled register data.

OBJECTIVES: This study aimed to evaluate characteristics of the work environment, job insecurity, and health of marginal part-time workers (8.0-14.9 hours/week) compared with full-time workers (32.0-40.0 hours/week). METHODS: The study population included employees in the survey Work Environment and Health in Denmark (WEHD) in 2012, 2014, or 2016 (n = 34 960). Survey information from WEHD on work environment and health was linked with register-based information of exposure based on working hours 3 months prior to the survey, obtained from the register Labour Market Account. Associations between marginal part-time work and work environment and health were assessed using logistic regression models. RESULTS: Marginal part-time workers reported less quantitative job demands, lower levels of influence at work, poorer support from colleagues and leaders, less job satisfaction and poorer safety, as well as more job insecurity. Results on negative social relations in the workplace and physical workload were more ambiguous. Marginal part-time workers were more likely to report poorer self-rated health, treatment-requiring illness, and depressive symptoms compared with full-time workers. Adjusting for characteristics of the work environment showed an indication of altered odds ratios for self-rated health and depressive symptoms, whereas job insecurity did not. CONCLUSIONS: This study finds that marginal part-time workers experience a poorer psychosocial work environment and safety, higher job insecurity, and poorer health than full-time workers. Work environment characteristics may confound or mediate the association between marginal part-time work and health. However, prospective studies are needed to determine the causal direction of the revealed associations.