Objectives The aim of this study was to investigate the effect of shift work and long working hours in midlife on the risk of dementia in old age. Methods The present study comprised 4766 participants from the Copenhagen Male Study. We used information on shift work (collected in 1970-1971 and 1985-1986), long working hours defined as >45 hours per week (collected in 1970-1971), socioeconomic status, sleep, stress, and cardiovascular risk factors. Information about dementia diagnoses was obtained from registers. Participants were followed until 2014 (mean length of follow-up was 17.8 years). We employed Poisson regression for the survival analyses and estimated incidence rate ratios (IRR) and their 95% confidence intervals (CI). Results We found no statistically significant association between shift work (IRR 0.86, 95% CI 0.70-1.05) or long working hours (IRR 0.97, 95% CI 0.79-1.19) and dementia. Adjustment for potential confounders and mediators did not change the estimates. Working shifts at both time points of exposure assessment was not associated with a higher incidence of dementia compared with non-shift workers at both time points (IRR 0.99, 95% CI 0.69-1.42). The lowest incidence of dementia was observed among participants who reported shift work at one time point (only in 1985-1986: IRR 0.44, 95% CI 0.16-1.23 and only in 1970-1971: IRR 0.58, 95% CI 0.31-1.11). Conclusion We did not find positive evidence of an association between shift work or long working hours and the incidence of dementia, but the negative findings may reflect the crude assessment of shift work and long working hours, which is a major limitation of the present study.

ObjectiveShift work and long working hours are potential risk factors for dementia, but previous studies on shift work, long working hours and dementia are sparse and their findings are conflicting. Therefore, we investigated the effect of night shift work and long working hours on dementia.DesignA longitudinal study.SettingDenmark.Participants3435 occupationally active men and women from the general working population.MethodsWork schedule covered day work (reference) and shift schedules without/with night work. Working hours covered <27, 28–36, 37 (reference), 38–44, and ≥45 hours/week. As the primary outcome, we used register-based information about dementia, and estimated incidence rate ratios (IRR) and 95% CI. Estimates were adjusted for gender, age, psychosocial work factors and cardiovascular risk factors.ResultsWe identified 85 dementia cases during a mean of 9.8 years of follow-up. We found a positive, but statistically insignificant association between night shift work and dementia (IRR=2.01; 95% CI: 0.87-4.65). Post hoc analyses indicated that this was only due to a higher risk in permanent night workers (IRR=3.25; 95% CI: 1.35-7.83). The dementia risk was also significantly higher among participants working 38–44 hours/week (IRR=2.08; 95% CI: 1.11-3.90) compared with those working 37 hours/week. We found no indications of a higher risk of dementia in participants working <37 hours/week or ≥45 hours/week.ConclusionWe did not find arguments that night shift work or long working hours increased dementia risk in general. However, we found a higher risk of dementia in specific subgroups, that is, permanent night workers and employees with moderately longer weekly working hours than the standard.

BackgroundStress-related mental disorders (SRMD), which correspond to the diagnostic code F43 in the International Classification of Diseases, version 10, rank among the leading causes of sickness absence in several European countries. Despite the size of this health problem, research on risk factors for severe medical outcomes, like suicidal behavior, is lacking to date. The aim of this study was to investigate predictors of suicide attempt and suicide among sickness absentees with SRMD.MethodsA cohort of 36,304 non-retired individuals, aged 16–64 years on 31.12.2004, with at least one sickness absence spell due to SRMD, initiated in 2005, was followed up with regard to suicide attempt (2006–2009) and suicide (2006–2008). Univariate and multivariate hazard ratios (HR) with 95% confidence intervals (CI) were estimated for a number of predictors.ResultsDuring the follow-up period, 266 individuals attempted suicide and 34 committed suicide. In the multivariate analyses, the following factors increased the risk of suicide attempt: =< 25 years of age, low educational level, lone parenthood, > 1 sickness absence spell, long duration of the first spell of sickness absence due to SRMD (> 180 days), > 4 and > 8 days of inpatient care due to somatic or mental diagnoses (2000–2005), and > 4 and > 1 outpatient visits due to somatic or mental diagnoses (2001–2005), respectively. Hazard ratios ranged from 1.4 to 4.2. Health care due to mental diagnoses and > 1 spell of sickness absence regardless of diagnosis were predictive of suicide.ConclusionsSeveral predictors related to socio-demographics, sickness absence and health-care consumption were identified as risk factors for suicidal behavior. Consideration of these risk factors is of both clinical and public health importance.

BackgroundThe spread of the highly pathogenic avian influenza (HPAI) H5N1 virus among poultry and humans has raised global concerns and has motivated government and public health organizations to initiate interventions to prevent the transmission of HPAI. In Bangladesh, H5N1 became endemic in poultry and seven human H5N1 cases have been reported since 2007, including one fatality. This study piloted messages to increase awareness about avian influenza and its prevention in two rural communities, and explored change in villagers’ awareness and behaviors attributable to the intervention.MethodsDuring 2009–10, a research team implemented the study in two rural villages in two districts of Bangladesh. The team used a focused ethnographic approach for data collection, including informal interviews and observations to provide detailed contextual information about community response to a newly emerging disease. They collected pre-intervention qualitative data for one month. Then another team disseminated preventive messages focused on safe slaughtering methods, through courtyard meetings and affixed posters in every household. After dissemination, the research team collected post-intervention data for one month.ResultsMore villagers reported hearing about ‘bird flu’ after the intervention compared to before the intervention. After the intervention, villagers commonly recalled changes in the color of combs and shanks of poultry as signs of avian influenza, and perceived zoonotic transmission of avian influenza through direct contact and through inhalation. Consequently the villagers valued covering the nose and mouth while handling sick and dead poultry as a preventive measure. Nevertheless, the team did not observe noticeable change in villagers’ behavior after the intervention. Villagers reported not following the recommended behaviors because of the perceived absence of avian influenza in their flocks, low risk of avian influenza, cost, inconvenience, personal discomfort, fear of being rebuked or ridiculed, and doubt about the necessity of the intervention.ConclusionsThe villagers’ awareness about avian influenza improved after the intervention, however, the intervention did not result in any measurable improvement in preventive behaviors. Low cost approaches that promote financial benefits and minimize personal discomfort should be developed and piloted.

Background: Psychological distress is potentially linked to the risk of dementia through neurologic and cardiovascular mechanisms. Vital exhaustion (VE) is a mental state of psychological distress, which could be a risk factor for dementia. Objective: To investigate whether VE is a risk factor for dementia in later life. Methods: We used data from 6,807 participants attending the third survey of the Copenhagen City Heart Study in 1991–1994. VE was assessed by 17 symptoms (score: 0–17) from the Maastricht Questionnaire. Information on dementia was obtained from national registers. Risk time for dementia was counted from five years after VE assessment for participants > 55 years at the time of VE assessment. For younger participants, risk time for dementia was counted from the year they turned 60 years and onwards. Participants were followed until 2016. We used Poisson regression to calculate incidence rate ratios (IRR) and their 95% confidence intervals (CI). Results: During an average follow-up of 10 years, 872 participants were registered with dementia. We found a dose-response relation between the number of VE symptoms and the incidence of dementia. For every additional VE symptom, the dementia incidence increased by 2% (IRR = 1.024; 95% CI: 1.004–1.043). Adjustment for socio-demographic and health-related factors did not change the results substantially. Neither did stratification by age, sex, educational level, and marital status. Conclusion: We found evidence that VE is a risk factor for dementia. Our sensitivity analyses supported that this association was not only due to VE being a potential prodromal sign of dementia.