Subjective sleepiness and accident risk avoiding the ecological fallacy

The present study of sleepiness and accident risk in a HI-FI car simulator aimed to provide subject-level relative risks (RR) with 95% confidence intervals (CI) for different levels of subjective sleepiness measured with the Karolinska Sleepiness Scale (KSS), 1 = very alert, 9 = very sleepy, fighting sleep, an effort to staying awake. Five male and five female shift workers, mean age 37 years, participated with a 2-h drive (08:00-10:00 hours) in a dynamic high-fidelity moving base driving simulator, after a night of work and after a night of sleep. Subjective sleepiness was measured with KSS every 5 min and events of incidents (two wheels outside the right lane), accidents (two wheels off the road or four wheels in opposite lane) and crashes (four wheels off the road) were recorded. The probability of an accident was modelled with a Generalized Linear Mixed Model approach to estimate subject-specific effects, rather than group average effects, to avoid the ecological fallacy. The results showed that sleepiness was strongly related to accident risk. An average subject was estimated at 28.2 times (95% CI RR = 10.7-74.1) increased risk at KSS = 8 and at 185 times (95% CI RR = 42-316) at KSS = 9 compared with KSS = 5. There were large individual differences in event propensity that complicates the prediction of absolute accident risk for individual subjects.     

Sleep disturbances as a predictor of occupational injuries among public sector workers

The association between disturbed sleep and increased risk of occupational injury has been observed in several cross-sectional and case–control studies, but prospective evidence is lacking. We examined prospectively whether sleep disturbances predicted occupational injuries in a large population of Finnish public sector employees. A total of 48 598 employees working in 10 municipalities and 21 hospitals in various parts of Finland were included. Sleep disturbances were assessed with the four-item Jenkins Sleep Problems Scale. Records of sickness absence due to occupational injury during the year following the survey were obtained from employers' registers. A proportion (9076; 22%) of participants reported disturbed sleep, and 978 (2.4%) had a recorded occupational injury. After adjustment for socio-demographic characteristics, the odds ratio (OR) for occupational injury was 1.38 [95% confidence interval (CI) 1.02–1.87] times higher for men with experiences of disturbed sleep than for those without sleep disturbances, but not significant for women. Of the sub-dimensions of sleep disturbances, the OR for occupational injury was 1.69 (95% CI 1.26–2.26) for women with difficulties initiating sleep, but not significant for men. These associations remained after additional adjustment for work stress, sleep length, obesity, alcohol use and mental health. This study suggests that sleep disturbances are a significant predictor of occupational injuries even after accounting for a range of covariates.     

Excessive daytime sleepiness and risk of occupational injuries in non-shift daytime workers

STUDY OBJECTIVES: Only a few studies have examined the possible association between excessive daytime sleepiness (EDS) and risk of occupational injuries, and most of them were based on self-reports. This study tested this association in daytime workers using injury data taken from organizational archives. DESIGN: A retrospective and prospective study. It covered injury occurrence during two years prior to a sleep disorder assessment/education procedure and injury occurrence in the following year. The workers were given the assessment results and, when applicable, a letter to the treating physician. SETTING: Eight industrial plants. Lectures and discussions on sleep disorders, treatment, and implications to safety and quality of life were conducted with small groups who completed the sleep assessment questionnaire beforehand. The workers completed the sleep assessment questionnaire prior to the lecture/discussion. PARTICIPANTS: 532 non-shift daytime workers. INTERVENTIONS: N/A. MEASURES AND RESULTS: A battery of questionnaires to assess EDS (by the Epworth Sleepiness Scale), suspected sleep disorders, sleep habits, and job and environmental conditions. Of the workers studied 22.6% had EDS. Most of those (96.3%) indicated that they had experienced this propensity for the past two years or more and 56% of them had experienced it for 10 years or more. Logistic regression analysis indicated that during the two-year period prior to the procedure, EDS was associated with an increased risk of sustaining a work injury (OR=2.23, 95% CI 1.30-3.81), even after controlling for possible confounders, including factory category, job and environmental conditions. In the year after the procedure, the injury rate decreased by one-third in the workers with EDS but remained unchanged in the workers without EDS. Consequently, the association between EDS and injury was no longer significant (OR=1.42, 95% CI 0.71-2.85). CONCLUSION: EDS is a prevalent phenomenon in non-shift daytime workers. Workers with EDS had over two-fold higher risk of sustaining an occupational injury. Providing workers with the assessment results and of the implications of EDS for safety may explain the decrease in occupational injuries upon follow-up. This decrease might have occurred either because of workers taking steps to reduce EDS and/or adopting safety behaviors.     

Psychological morbidity in general practice managers: a descriptive and explanatory study.

BACKGROUND: Proposals to establish an occupational health service for primary care should be informed by knowledge of the health needs of general practice employees. AIM: To determine the prevalence and occupational correlates of stress, anxiety, and depression among practice managers in two contrasting health authorities in England. METHOD: A postal questionnaire, soliciting information about stress induced by work-related activities, which contained the General Health Questionnaire (GHQ) and Hospital Anxiety and Depression Scale (HADS), was sent to all 149 practice managers in two health authorities areas of south-east England. RESULTS: Completed questionnaires were returned by 111 (75%) managers; 41/111 (37%) achieved GHQ case status with scores on HADS indicating that 49/111 (44%) classified themselves as anxious and 19/111 (17%) as depressed. The likelihood of being a case was found to be higher in managers from practices with larger numbers of GP partners (P = 0.02) and in managers from practices not in receipt of deprivation payments (P = 0.03). Multiple logistic regression showed that managers' perceived difficulties with general practice administration duties (relative ratio [RR] = 3.27, 95% confidence interval [CI] = 1.22-8.75) and dealings with GPs (RR = 1.86, 95% CI = 1.03-3.34) were the most powerful predictors of case status. CONCLUSION: The questionnaire uncovered high prevalences of self-reported stress, anxiety, and depression in general practice managers. Although the vast majority of National Health Service (NHS) employees have access to an occupational health service, no such source of support exists for those working in general practice. The NHS needs to establish an occupational health service that caters to the needs of clinical and non-clinical members of primary health care teams.     

Sleep duration and sleep complaints and risk of myocardial infarction in middle-aged men and women from the general population: the MONICA/KORA Augsburg cohort study

STUDY OBJECTIVES: To examine gender-specific associations between sleep duration and sleep complaints and incident myocardial infarction (MI). DESIGN: Cohort study. SETTING: A representative population sample of middle-aged subjects in Germany. PARTICIPANTS: The study was based on 3508 men and 3388 women (aged 45 to 74 years) who participated in one of the 3 MONICA (Monitoring trends and determinants on cardiovascular diseases) Augsburg surveys between 1984 and 1995, who were free of MI and angina pectoris at baseline and were followed up until 2002. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: A total of 295 cases of incident MI among men and 85 among women occurred during a mean follow-up period of 10.1 years. Compared with women sleeping 8 hours, the multivariable adjusted hazard ratio (HR) of MI among women sleeping < or =5 hours was 2.98 (95% CI, 1.48-6.03), and among women sleeping > or =9 hours 1.40 (95% CI, 0.74-2.64); the corresponding HRs among men were 1.13 (95% CI, 0.66-1.92) and 1.07 (95% CI, 0.75-1.53). In multivariable analysis the relative risk of an incident MI for men and women with difficulties maintaining sleep was 1.12 (95% CI, 0.84-1.48) and 1.53 (95% CI, 0.99-2.37), respectively, and for men and women with difficulties initiating sleep the relative risk was 1.16 (95% CI, 0.82-1.63) and 1.30 (95% CI, 0.81-2.06), respectively. CONCLUSIONS: Modest associations between short sleep duration and difficulties maintaining sleep and incident MI were seen in middle-aged women but not men from the general population.     

A Case-Crossover Study of Sleep and Work Hours and the Risk of Road Traffic Accidents

Study Objectives:

Sleepiness, prolonged wakefulness, and extended work hours have been associated with increased risk of injuries and road accidents. The authors'' objective was to study the relation between those factors and road accidents using a case-crossover design, effective in estimating the risk of acute events associated with transient, short effect exposures.

Design:

Five hundred seventy-four injured drivers presenting for care after road accidents to the Emergency Room of Udine, Italy, were enrolled in the study from March 2007 to March 2008. Sleep, work, and driving patterns in the 48 h before the accident were assessed through an interview.

Measurements and Results:

The relative risk (RR) of accident associated with each exposure was estimated using the case-crossover matched pair interval approach. Sleeping ≥ 11 h daily was associated with a decrease of the RR, as was sleeping less than usual. Being awake ≥ 16 h and, possibly, working > 12 h daily were associated with increases in the RR.

Conclusions:

Extended work hours and prolonged wakefulness increase the risk of road accidents and suggest that awareness should be raised among drivers. The findings regarding acute sleep amount are less clear, possibly due to an effect of chronic sleep loss.

Citation:

Valent F; Di Bartolomeo S; Marchetti R; Sbrojavacca R; Barbone F. A case-crossover study of sleep and work hours and the risk of road traffic accidents. SLEEP 2010;33(3):349-354.     

Associations between smoking, screening, and death caused by cervical cancer in Korean women

PURPOSE: Cervical cancer is a major women's health problem in the world today. The purpose of this study was to estimate the incidence and mortality rates and to investigate risk factors for cervical cancer in Korean women. MATERIALS AND METHODS: Reproductive factors, cigarette smoking, as well as the risk of incidence and death from cervical cancer were examined in a 12-year prospective cohort study of 475,398 Korean women aged 30 to 95 years who received health insurance from the National Health Insurance Corporation and who had a medical evaluation in 1992. Relative risks (RR) and 95% confidence intervals (CI) were calculated using the Cox proportional hazards model after adjusting for age, body mass index, cigarette smoking, alcohol use, menarche, parity, and Papanicolaou test status. RESULTS: This study showed that the RR of death due to cervical cancer among current smokers was two times higher compared with non- smokers (RR=2.00; 95% CI, 1.23-2.91). In addition, the RR of death due to cervical cancer among all women who smoked > or = 10 cigarettes/day was 2.4 times higher than the RR among women that had never smoked. More interestingly, those who had never been screened by Papanicolaou smears had twice the risk of death due to cervical cancer (RR =2.00; 95% CI, 1.37-1.81). CONCLUSION: Our prospective study concluded that current smokers had an increased risk of death due to cervical cancer. We suggest that the target age group for cervical cancer screening tests be reconsidered and should begin as early as possible.     

Poor adherence to placebo or amiodarone therapy predicts mortality: results from the CAMIAT study. Canadian Amiodarone Myocardial Infarction Arrhythmia Trial.

OBJECTIVE: This study examined the relationship between adherence, mortality, and psychosocial factors. METHODS: Subjects were 1141 patients participating in the Canadian Amiodarone Myocardial Infarction Arrhythmia Trial. Poor adherence to study medication (amiodarone or placebo), measured by pill count over 2 years, was defined as the lower 20th percentile of the pill count distribution. Predictors of adherence were also studied and included demographic and cardiac variables and, in a subset of participants (N = 671), measures of depression, distress, hostility, and social support. RESULTS: In survival analysis controlling for cardiac and demographic variables, poor adherence in the placebo and amiodarone groups was associated with an increased risk of sudden cardiac death (relative risk (RR) = 2.11, 95% confidence interval (CI) = 1.03-4.56, p < .05; and RR = 3.15, 95% CI = 1.34-7.44, p < .01, respectively), total cardiac mortality (RR = 2.04, 95% CI = 1.12-3.72, p < .02; and RR = 2.49, 95% CI = 1.32-4.72, p < .01, respectively), and all-cause mortality (RR = 2.25, 95% CI = 1.27-3.97, p < .001; and RR = 2.34, 95% CI = 1.32-4.17, p < .004, respectively). Logistic regression analysis identified two predictors of poor adherence to placebo: age > 70 years (odds ratio = 2.18, 95% CI = 1.11-4.29, p < .03) and social activities in the month before the index heart attack (odds ratio = 1.02, 95% CI = 1.00-1.04, p < .05). CONCLUSIONS: Poor adherence is associated with a greater risk of mortality. The relationship between adherence and social activities suggests a higher motivation to adhere to treatment in individuals more engaged in enjoyable activities.     

Depression and risk of sudden cardiac death after acute myocardial infarction: testing for the confounding effects of fatigue

OBJECTIVES: This study examined the impact of depressive symptoms and social support on 2-year sudden cardiac death (SCD) risk, controlling for fatigue symptoms. METHODS: Myocardial infarction (MI) patients (N = 671) participating in the Canadian Amiodarone Myocardial Infarction Arrhythmia Trial completed measures of depression, hostility, and social support. RESULTS: After controlling for significant biological predictors, psychosocial predictors of increased SCD risk in the survival analysis were greater social network contacts (RR = 1.04; 95% CI = 1.01-1.06; p < .007), lower social participation (RR = 0.98; 95% CI = 0.96-1.00; p < .05), and, in placebo-treated patients, elevated depressive symptoms (RR = 2.45; 95% CI = 1.14-5.35; p < .02). Fatigue was associated with SCD (RR = 1.31; 95% CI = 1.11-1.53; p < .001), and, when included in the model, diminished the influence of depression (RR = 1.73; 95% CI = 0.75-3.98; p = .20). When the cognitive-affective depressive symptoms were examined separately from somatic symptoms, there was a trend for an association between cognitive-affective symptoms and SCD in placebo-treated patients after controlling for fatigue (RR = 1.09; 95% CI = 0.99-1.19, p < .06). CONCLUSIONS: Symptoms of depression and fatigue overlap in patients with MI. The trend for the cognitive-affective symptoms of depression to be associated with SCD risk, even after controlling for dyspnea/fatigue, suggests that the association between depression and mortality after AMI cannot be entirely explained as a confound of cardiac-related fatigue. The independent contribution of social participation suggests a role of both depressive symptomatology and social factors in influencing mortality risk after MI.     

Prevalence of occupational allergy to bell pepper pollen in greenhouses in the Netherlands

BACKGROUND: An increasing number of allergic complaints appear to have occurred among bell pepper greenhouse employees. OBJECTIVE: The aim of this study was to estimate the prevalence of work-related allergic symptoms and the prevalence of sensitization to specific occupational allergens and its determinants. METHODS: We studied 472 employees who were invited to answer an extensive questionnaire and to be tested on location with inhalant allergens and home-made extracts of the bell pepper plant. In addition, peak expiratory flow monitoring and RASTs were performed. RESULTS: Work-related symptoms were reported in 53.8% of all cases. Sensitization to the bell pepper plant was found in 35.4%. Positive reactions to leaf, stem and/or juice, however, were associated in nearly 90% with sensitization to pollen, which appeared to be most important allergen of the plant. Sensitization to the bell pepper plant and inhalant atopy were considered the most important risk factors for the occurrence of work-related symptoms of the upper airways (PRR 2.63, CI 2.11-3.25 and PRR 2.25, CI 1.82-2.79) as well as of the lower airways (PRR 4.08, CI 2.38-7.00 and PRR 3.16, CI 1.87-5.33). CONCLUSION: There is a surprisingly high prevalence of work-related respiratory symptoms (53.8%) in bell pepper horticulture. In two-thirds of the employees, symptoms at work were associated with an IgE-mediated allergy due to the high and chronic exposure to bell pepper pollen. Complaints at work without specific sensitization to bell pepper pollen can be caused by non-specific hyper-reactivity or atopy to other occupational allergens. The extent of this occupational allergy has important consequences for the health care of this large, still growing occupational group.     

Trends in AIDS and mortality in HIV-infected subjects with hemophilia from 1985 to 2003: the competing risks for death between AIDS and liver disease

OBJECTIVE: To study trends in progression to AIDS, all-cause mortality, and cause-specific mortality (AIDS-related, liver disease, and hemorrhagic complications) over calendar periods with different exposure to highly active antiretroviral therapy (HAART) in a cohort of hemophiliacs in Spain, taking into account the competing risks of the causes of death. METHODS: Multicenter cohort of HIV-infected hemophiliacs. HIV seroconversion was estimated using mathematic techniques for interval-censored data from 1979 through 1985. Rates of AIDS and cause-specific death were calculated by Poisson regression, allowing for late entry, for the periods 1985 through 1992, 1993 through 1996, 1997 through 2000 (early HAART), and 2001 through 2003 (late HAART), also allowing for competing risks. RESULTS: Of 585 subjects, 44% were younger than 15 years of age, 82% had severe hemophilia, 86% had type A hemophilia, and the median seroconversion date was October 1982. Calendar period and age at HIV seroconversion strongly influenced AIDS and death rates. Compared with 1993 through 1996, decreases of 75% (relative risk [RR] = 0.25, 95% confidence interval [CI]: 0.14 to 0.43) and 72% (RR = 0.28, 95% CI: 0.12 to 0.63) in the RR of AIDS were observed in early and late HAART. For all-cause mortality, 72% (RR = 0.28, 95% CI: 0.18 to 0.42) and 83% (RR = 0.17, 95% CI: 0.09 to 0.33) decreases were observed by 1997 through 2000 and 2001 through 2003. For liver-related deaths, increases were observed in the late-HAART period (RR = 2.80, 95% CI: 0.94 to 8.36) compared with 1993 through 1996, but using competing risks, this RR was substantially reduced (RR = 1.70, 95% CI: 0.57 to 5.04). DISCUSSION: Major reductions in AIDS and death rates were observed from 1997 to 2003 in hemophiliacs. These survival improvements are largely attributable to decreases in AIDS-related deaths and have been accompanied by increases in liver disease death rates, which are overestimated if competing risks are not taken into account.     

Factors associated with failed and completed railway suicides

BACKGROUND: The present analysis aimed to assess the proportion of survivors of railway suicides and to compare survivors and completers in terms of personal characteristics and temporal patterns surrounding the event, to identify potential differences between those who completed suicide and those who survived a serious suicide attempt. METHODS: A total of 5731 suicide victims (including 4003 cases with complete documentation on sex) of the German central railway registry of person accidents covering a six-year observation period of 1997 to 2002 and satisfying the operational definition of an act of suicidal behaviour according to the ICD-10 were included into the data set. To assess the impact of sex, age, local and temporal factors on case fatality, a multivariate logistic regression analysis was performed. RESULTS: A minority of 540 (9.4%) subjects survived the suicidal event leading to a fatal to non-fatal ratio of 9.6:1 (chi(2)-test for equal proportions, p<0.001). Multivariate logistic regression analysis identified the following variables as risk factors for fatal outcome: men (vs. women: Odds ratio (OR)=2.05; 95% CI: 1.65-2.56), night (vs. day: OR=1.80; 95% CI: 1.43-2.27), open track (vs. station area: OR=2.95; 95% CI: 2.36-2.67) and main railway line (vs. local railway line: OR=2.29; 95% CI: 1.43-3.68). Interactions between two factors on fatal outcome were multivariate tested but showed no significance. CONCLUSIONS: Close to 10% of all railway suicide attempts are nonfatal. Fatality of suicidal behaviour on railway tracks is significantly associated with male sex pointing to a certain degree of ambivalence. Higher odds to die on open track area, fast track lines and during night-time suggest a reduced opportunity to survive due to circumstances.     

Increased longevity in older users of postmenopausal estrogen therapy: the Leisure World Cohort Study

OBJECTIVE: To examine the effect of postmenopausal estrogen therapy (ET), including duration and recency of use, on all-cause mortality in older women. DESIGN: As part of a prospective cohort study of residents of a California retirement community begun in the early 1980s, Leisure World Cohort women (median age, 73 y) completed a postal health survey including details on ET use and were followed up for 22 years (1981-2003). Age- and multivariate-adjusted risk ratios (RR) and 95% CIs were calculated using proportional hazard regression. RESULTS: Of the 8,801 women, 6,626 died during follow-up (median age, 88 y). ET users had an age-adjusted mortality rate of 52.9 per 1,000 person-years compared with 56.5 among lifetime nonusers (RR = 0.91; 95% CI, 0.87-0.96). Risk of death decreased with both increasing duration of ET and decreasing years since last use (P for trend <0.001). The risk was lowest among long-term (> or =15 y) users (RR = 0.83; 95% CI, 0.74-0.93 for 15-19 y and RR = 0.87; 95% CI, 0.80-0.94 for 20+ y). For long-term users, the age-adjusted mortality rate was 50.4 per 1,000 person-years. Lower-dose users (< or =0.625 mg) had a slightly better survival rate than higher-dose users (RR = 0.84; 95% CI, 0.78-0.91 vs RR = 0.91; 95% CI, 0.83-0.97). Risk did not differ by route of administration (P = 0.56). Further adjustment for potential confounders had little effect on the observed RRs for ET. CONCLUSION: Long-term ET is associated with lower all-cause mortality in older women.     

CERT2 ceramide- and phospholipid-based risk score and major adverse cardiovascular events: A systematic review and meta-analysis

Accumulating evidence over the last decade suggests the promising role of ceramides as potential mediators of coronary artery disease (CAD) or prognostic biomarkers of its clinical course. This meta-analysis (CRD42021241058) aimed to assess the prognostic value of a ceramide- and phosphatidylcholine-based risk score, Coronary Event Risk Test 2 (CERT2) score, for the prediction of major adverse cardiovascular events (MACE: cardiovascular death, myocardial infarction or stroke) in 26,896 individuals with established CAD. Patients with CERT2=0-3 were used as a reference group. Pooled risk ratio (RR) of MACE among patients with CERT2=4-6 was equal to 1.35 (95% confidence intervals, CI: 1.11-1.64). Patients with CERT2=7-8 had an 81% increased risk of MACE (RR=1.81, CI: 1.40-2.34), while those with CERT2=9-12 had a 165% increased risk of MACE (RR=2.65, CI: 1.85-3.80). Subgroup analysis in patients with chronic coronary syndrome yielded an adjusted hazard ratio for MACE equal to 1.20 (CI: 1.09-1.32) per one standard deviation increase of CERT2 score. A summary c-statistic of the score combined with classical risk assessment model was found equal to 0.68 (95% CI: 0.58 to 0.77; approximate 95% prediction interval 0.38 to 0.88). Therefore, CERT2 score seems to emerge as a robust predictor of MACE. However, additional research is warranted to establish the cost-effectiveness of CERT2 score calculation for the determination of residual risk in patients with CAD.     

Factors associated with severity of occupational asthma with a latency period at diagnosis

BACKGROUND: Severity of occupational asthma at diagnosis is an important prognostic factor. The aim of this study was to determine which factors affect the severity of occupational asthma with a latency period at diagnosis. METHODS: The study population consisted of 229 consecutive subjects with occupational asthma with a latency period recruited by four occupational health departments and divided into two groups according to the severity of the disease at diagnosis. The moderate-severe (FEV(1) <70% predicted, or PD(20) methacholine /=70% predicted and PD(20) methacholine >300 microg, n = 128) groups were compared in terms of clinical and demographic parameters. Multivariate analysis using logistic regressions was performed to examine factors associated with asthma severity. RESULTS: Duration of symptoms before diagnosis was significantly longer in the moderate-severe group (mean +/- SD: 6.3 +/- 6.8 years vs 3.4 +/- 4.4 years, P < 0.001). Sex ratio, age, atopy, smoking habits, duration of exposure before symptoms, and molecular weight of the causal agent were not significantly different between the two groups. On multivariate analysis, only duration of symptoms before diagnosis was associated with asthma severity (aOR = 1.12, 95% CI 1.05-1.18, P < 0.001). CONCLUSIONS: Severity of occupational asthma with a latency period at diagnosis was associated with duration of symptoms before diagnosis, but not with the type of causal agent. This finding emphasizes the need for early diagnosis and avoidance of exposure.     

Sleep disturbances as a predictor of cause-specific work disability and delayed return to work

Study Objective:

To examine sleep disturbances as a predictor of cause-specific work disability and delayed return to work.

Design:

Prospective observational cohort study linking survey data on sleep disturbances with records of work disability (≥ 90 days sickness absence, disability pension, or death) obtained from national registers.

Setting:

Public sector employees in Finland.

Participants:

56,732 participants (mean age 44.4 years, 80% female), who were at work and free of work disability at the study inception.

Measurements and Results:

During a mean follow-up of 3.3 years, incident diagnosis-specific work disability was observed in 4,028 (7%) employees. Of those, 2,347 (60%) returned to work. Sleep disturbances 5-7 nights per week predicted work disability due to mental disorders (hazard ratio [HR] 1.6, 95% confidence interval [CI] 1.3-1.9) and diseases of the circulatory system (HR = 1.6, 95% CI 1.2-2.1), musculoskeletal system (HR = 1.6, 95% CI 1.4-1.8) and nervous system (HR = 1.5, 95% CI 1.0-2.2), and injuries and poisonings (HR = 1.6, 95% CI 1.2-2.1) after controlling for baseline age, sex, socioeconomic status, night/shift work, health behaviors (e.g., smoking, exercise), diagnosed somatic diseases, use of pain killers, depression, and anxiety. In addition, sleep disturbances prior to disability were associated with higher likelihood of not returning to work after work disability from musculoskeletal diseases (HR = 1.2, 95% CI 1.1-1.7) and, in men, after work disability due to mental disorders (HR = 4.4, 95% CI 1.7-11.1).

Conclusions:

Sleep disturbances are associated with increased risk for subsequent disabling mental disorders and various physical illnesses. They also predict the outcome of work disability due to musculoskeletal disorders.

Citation:

Salo P; Oksanen T; Sivertsen B; Hall M; Pentti J; Virtanen M; Vahtera J; Kivimäki M. Sleep disturbances as a predictor of cause-specific work disability and delayed return to work. SLEEP 2010;33(10):1323-1331.     

Time course of onset of sensitization to common and occupational inhalants in apprentices

BACKGROUND: Incident sensitization to common allergens in the setting of sensitization to an occupational allergen has not been described. OBJECTIVE: Our aim was to determine the risk and timing of development of sensitization to common allergens in subjects with incident sensitization to a work-related allergen. METHODS: Data from a cohort of 769 apprentices in animal-health technology, pastry making, and dental hygiene were used. Skin prick tests to work-related allergens (laboratory animal, flour, and latex) and common allergens (mites, molds, pets, and pollen) were administered at baseline and at up to 3 subsequent annual visits. Risk ratios (RRs) and 95% CIs were calculated. RESULTS: Eighty-three subjects had sensitization to a work-related allergen. Four (4.8%) subjects became sensitized to common and then occupational allergens. Nine (10.8%) subjects had sensitization to a common allergen after sensitization to a work-related allergen. In 20 (24.1%) subjects new sensitizations to specific and common allergens were detected simultaneously. Fifty subjects remained free from new sensitization to occupational allergen during development of sensitization to common allergens. An increased risk of development of sensitization to molds (RR = 3.49) and pets (RR = 2.51) was found in subjects with incident sensitization to occupational allergens relative to the risk in subjects without sensitization. CONCLUSION: New sensitization to common aeroallergens is frequent in subjects not previously exposed to work-related allergens; it often occurs around the same time as sensitization to work-related agents. Subjects with new occupational sensitization are at a greater risk of development of sensitization to common aeroallergens than subjects without sensitization.     

Sleep duration associated with mortality in elderly, but not middle-aged, adults in a large US sample

STUDY OBJECTIVES: To explore age differences in the relationship between sleep duration and mortality by conducting analyses stratified by age. Both short and long sleep durations have been found to be associated with mortality. Short sleep duration is associated with negative health outcomes, but there is little evidence that long sleep duration has adverse health effects. No epidemiologic studies have published multivariate analyses stratified by age, even though life expectancy is 75 years and the majority of deaths occur in the elderly. DESIGN: Multivariate longitudinal analyses of the first National Health and Nutrition Examination Survey using Cox proportional hazards models. SETTING: Probability sample (n = 9789) of the civilian noninstitutionalized population of the United States between 1982 and 1992. PARTICIPANTS: Subjects aged 32 to 86 years. MEASUREMENTS AND RESULTS: In multivariate analyses controlling for many covariates, no relationship was found in middle-aged subjects between short sleep of 5 hours or less and mortality (hazards ratio [HR] = 0.67, 95% confidence interval [CI] 0.43-1.05) or long sleep of 9 hours or more and mortality (HR = 1.04, 95% CI 0.66-1.65). A U-shaped relationship was found only in elderly subjects, with both short sleep duration (HR = 1.27, 95% CI 1.06-1.53) and long sleep duration (HR = 1.36, 95% CI 1.15-1.60) having significantly higher HRs. CONCLUSIONS: The relationship between sleep duration and mortality is largely influenced by deaths in elderly subjects and by the measurement of sleep durations closely before death. Long sleep duration is unlikely to contribute toward mortality but, rather, is a consequence of medical conditions and age-related sleep changes.     

Relationships of occupational stress to insomnia and short sleep in Japanese workers

STUDY OBJECTIVE: The aims of this study were to (a) examine the association between occupational stress and insomnia and short sleep in Japanese workers and (b) demonstrate the difference between 2 occupational stress models-Effort Reward Imbalance and the Demand Control Model. DESIGN: All data were obtained via self-administrated questionnaires and annual health checkups. Insomnia was evaluated by the Athens Insomnia Scale, and short sleep was defined as less than 6 hours sleep per day. SETTING: Employees at local governments and a transit company who had annual health checkups during the period from April 2003 to March 2004. PARTICIPANTS: After excluding participants without complete data, data from 6,997 men and 1,773 women were analyzed. INTERVENTION: N/A. MEASUREMENTS AND RESULTS: In men, high occupational stresses were significantly associated with insomnia, especially a high level of Effort Reward Imbalance (defined as the presence of high effort and low reward), had a remarkably higher odds ratio. In women, high occupational stresses were significantly associated with insomnia as well. High occupational stresses were significantly associated with short sleep in men. However, in women, only Effort Reward Imbalance showed a significant association with short sleep. CONCLUSIONS: This study suggested that occupational stress is a possible risk factor for insomnia and short sleep.     

Incidence of HIV infection in stable sexual partnerships: a retrospective cohort study of 1802 couples in Mwanza Region,Tanzania

OBJECTIVE: To describe the dynamics of HIV transmission in stable sexual partnerships in rural Tanzania. DESIGN: Retrospective cohort study nested within community-randomized trial to investigate the impact of a sexually transmitted disease treatment program. METHODS: A cohort of 1802 couples was followed up for 2 years, with the HIV status of each couple assessed at baseline and follow-up. RESULTS: At baseline, 96.7% of couples were concordant-negative, 0.9% were concordant-positive, 1.2% were discordant with the male partner being HIV-positive, and 1.2% were discordant with the female partner being HIV-positive. Individuals living with an HIV-positive partner were more likely to be HIV-positive at baseline (women: odds ratio [OR] = 75.7, 95% confidence interval [CI]: 33.4-172; men: OR = 62.4, CI: 28.5-137). Seroincidence rates in discordant couples were 10 per 100 person-years (py) and 5 per 100 py for women and men, respectively (rate ratio [RR] = 2.0, CI: 0.28-22.1). In concordant-negative couples, seroincidence rates were 0.17 per 100 py in women and 0.45 per 100 py in men (RR = 0.38, CI: 0.12-1.04). Individuals living in discordant couples were at a greatly increased risk of infection compared with individuals in concordant-negative couples (RR = 57.9, CI: 12.0-244 for women; RR = 11.0, CI: 1.2-47.5 for men). CONCLUSION: Men were more likely than women to introduce HIV infection in concordant-negative partnerships. In discordant couples, incidence in HIV-negative women was twice as high as in men. HIV-negative individuals in discordant partnerships are at high risk of infection, and preventive interventions targeted at such individuals are urgently needed.