Breast-feeding and childhood-onset type 1 diabetes: a pooled analysis of individual participant data from 43 observational studies.

OBJECTIVE: To investigate if there is a reduced risk of type 1 diabetes in children breastfed or exclusively breastfed by performing a pooled analysis with adjustment for recognized confounders. RESEARCH DESIGN AND METHODS: Relevant studies were identified from literature searches using MEDLINE, Web of Science, and EMBASE. Authors of relevant studies were asked to provide individual participant data or conduct prespecified analyses. Meta-analysis techniques were used to combine odds ratios (ORs) and investigate heterogeneity between studies. RESULTS: Data were available from 43 studies including 9,874 patients with type 1 diabetes. Overall, there was a reduction in the risk of diabetes after exclusive breast-feeding for >2 weeks (20 studies; OR = 0.75, 95% CI 0.64-0.88), the association after exclusive breast-feeding for >3 months was weaker (30 studies; OR = 0.87, 95% CI 0.75-1.00), and no association was observed after (nonexclusive) breast-feeding for >2 weeks (28 studies; OR = 0.93, 95% CI 0.81-1.07) or >3 months (29 studies; OR = 0.88, 95% CI 0.78-1.00). These associations were all subject to marked heterogeneity (I(2) = 58, 76, 54, and 68%, respectively). In studies with lower risk of bias, the reduced risk after exclusive breast-feeding for >2 weeks remained (12 studies; OR = 0.86, 95% CI 0.75-0.99), and heterogeneity was reduced (I(2) = 0%). Adjustments for potential confounders altered these estimates very little. CONCLUSIONS: The pooled analysis suggests weak protective associations between exclusive breast-feeding and type 1 diabetes risk. However, these findings are difficult to interpret because of the marked variation in effect and possible biases (particularly recall bias) inherent in the included studies.

Chewing gum, occupational stress, work performance and wellbeing. An intervention study.

An intervention study was carried out to examine the effects of chewing gum on occupational stress and related outcomes. 101 volunteers from Cardiff University completed the study. The results showed that chewing gum reduced stress (both at work and outside work), reduced fatigue, reduced anxiety and depression and led to a more positive mood. Chewing gum was also associated with perceptions of better performance (both at work and outside).

Interbirth interval is associated with childhood type 1 diabetes risk.

Short interbirth interval has been associated with maternal complications and childhood autism and leukemia, possibly due to deficiencies in maternal micronutrients at conception or increased exposure to sibling infections. A possible association between interbirth interval and subsequent risk of childhood type 1 diabetes has not been investigated. A secondary analysis of 14 published observational studies of perinatal risk factors for type 1 diabetes was conducted. Risk estimates of diabetes by category of interbirth interval were calculated for each study. Random effects models were used to calculate pooled odds ratios (ORs) and investigate heterogeneity between studies. Overall, 2,787 children with type 1 diabetes were included. There was a reduction in the risk of childhood type 1 diabetes in children born to mothers after interbirth intervals <3 years compared with longer interbirth intervals (OR 0.82 [95% CI 0.72-0.93]). Adjustments for various potential confounders little altered this estimate. In conclusion, there was evidence of a 20% reduction in the risk of childhood diabetes in children born to mothers after interbirth intervals <3 years.

Birth order and childhood type 1 diabetes risk: a pooled analysis of 31 observational studies.

BACKGROUND: The incidence rates of childhood onset type 1 diabetes are almost universally increasing across the globe but the aetiology of the disease remains largely unknown. We investigated whether birth order is associated with the risk of childhood diabetes by performing a pooled analysis of previous studies. METHODS: Relevant studies published before January 2010 were identified from MEDLINE, Web of Science and EMBASE. Authors of studies provided individual patient data or conducted pre-specified analyses. Meta-analysis techniques were used to derive combined odds ratios (ORs), before and after adjustment for confounders, and investigate heterogeneity. RESULTS: Data were available for 6 cohort and 25 case-control studies, including 11,955 cases of type 1 diabetes. Overall, there was no evidence of an association prior to adjustment for confounders. After adjustment for maternal age at birth and other confounders, a reduction in the risk of diabetes in second- or later born children became apparent [fully adjusted OR = 0.90 95% confidence interval (CI) 0.83-0.98; P = 0.02] but this association varied markedly between studies (I² = 67%). An a priori subgroup analysis showed that the association was stronger and more consistent in children < 5 years of age (n = 25 studies, maternal age adjusted OR = 0.84 95% CI 0.75, 0.93; I² = 23%). CONCLUSION: Although the association varied between studies, there was some evidence of a lower risk of childhood onset type 1 diabetes with increasing birth order, particularly in children aged < 5 years. This finding could reflect increased exposure to infections in early life in later born children.

Maternal age at birth and childhood type 1 diabetes: a pooled analysis of 30 observational studies.

OBJECTIVE: The aim if the study was to investigate whether children born to older mothers have an increased risk of type 1 diabetes by performing a pooled analysis of previous studies using individual patient data to adjust for recognized confounders. RESEARCH DESIGN AND METHODS: Relevant studies published before June 2009 were identified from MEDLINE, Web of Science, and EMBASE. Authors of studies were contacted and asked to provide individual patient data or conduct prespecified analyses. Risk estimates of type 1 diabetes by maternal age were calculated for each study, before and after adjustment for potential confounders. Meta-analysis techniques were used to derive combined odds ratios and to investigate heterogeneity among studies. RESULTS: Data were available for 5 cohort and 25 case-control studies, including 14,724 cases of type 1 diabetes. Overall, there was, on average, a 5% (95% CI 2-9) increase in childhood type 1 diabetes odds per 5-year increase in maternal age (P = 0.006), but there was heterogeneity among studies (heterogeneity I(2) = 70%). In studies with a low risk of bias, there was a more marked increase in diabetes odds of 10% per 5-year increase in maternal age. Adjustments for potential confounders little altered these estimates. CONCLUSIONS: There was evidence of a weak but significant linear increase in the risk of childhood type 1 diabetes across the range of maternal ages, but the magnitude of association varied between studies. A very small percentage of the increase in the incidence of childhood type 1 diabetes in recent years could be explained by increases in maternal age.

Fatigue and health in a seafaring population.

BACKGROUND: Occupational fatigue is relatively common within the general population and has been linked to reduced performance, injury and longer term ill-health. Despite growing acknowledgement of this problem in the maritime sector, little research has been conducted into the risk factors, prevalence and consequences of seafarers' fatigue. AIMS: To examine the prevalence of fatigue among seafarers, identify potential risk factors and assess possible links with poor performance and ill-health. METHODS: Cross-sectional questionnaire survey of seafarers working in the offshore oil support, short-sea and deep-sea shipping industries. A number of tools were used including the fatigue subscale of the profile of fatigue-related symptoms, the Cognitive Failures Questionnaire, the General Health Questionnaire and the SF36 General Health scale. RESULTS: In all, 1855 questionnaires were completed giving an overall response rate of 20%. Fatigue symptoms were associated with a range of occupational and environmental factors, many unique to seafaring. Reporting a greater number of risk factors was associated with greater fatigue [e.g. OR = 2.53 (1.90-3.35) for those with three or four risk factors and OR = 9.54 (6.95-13.09) for those with five or more risk factors]. There was also a strong link between fatigue and poorer cognitive and health outcomes, with fatigue the most important of a number of risk factors, accounting for 10-14% of the variance. CONCLUSIONS: Seafarers' fatigue could impact on safety within the industry and may be linked to longer term individual ill-health. It can only be addressed by considering how multiple factors combine to contribute to fatigue.

Seafarers' fatigue: a review of the recent literature.

Fatigue has been noticeably under-researched in the maritime domain compared to other transport sectors. In a review of the literature 11 databases were searched in order to assess recent developments in the field and distil those issues of greatest concern and challenge to the seafaring community. Whilst diversity in the seafaring population has the potential to make global fatigue estimates meaningless, evidence of mis-recorded working hours shows how cultural and commercial pressures are universally shared.

Racial discrimination, ethnicity and work stress.

BACKGROUND: Previous research has suggested higher work stress among minority ethnic workers. AIMS: To determine levels of work stress in three ethnic groups, consider the contribution of racial discrimination to the groups' profiles of occupational and demographic associations with stress, and assess the association between work stress and well-being. METHODS: A household quota sample design was used, and 204 black African-Caribbean, 206 Bangladeshi and 216 white (UK born) working people took part in structured interviews. RESULTS: More black African-Caribbean respondents reported high work stress than either Bangladeshi or white respondents. Reported racial discrimination among black African-Caribbean female respondents was strongly associated with perceived work stress. Among the black African-Caribbean respondents, women who reported experiencing racial discrimination at work had higher levels of psychological distress. CONCLUSIONS: Perceived work stress may be underpinned by exposure to racial discrimination at work among black African-Caribbean women, and this may affect their psychological well-being.

The prevention and management of seafarers' fatigue: a review.

Global concern about the extent of seafarer fatigue is widely evident across the shipping industry. This paper provides an evaluation of the extent to which fatigue can be prevented and managed. Given the diversity of activities undertaken in the maritime sector, and the different profiles of fatigue risk factors in different work groups, it is clear that a range of strategies will need to be implemented. One conclusion from the review is that current legislation and guidance on fatigue has not had the desired effect. The way forward is to treat seafarers' fatigue as a serious health and safety issue. A starting point must be to take a more robust approach to regulation. Manning levels need to be addressed in a realistic way, that prevents economic advantage accruing to those operating at bare minimum and the issue of false record-keeping requires urgent attention. This must be supplemented with appropriate training and guidance regarding avoidance of fatigue and the creation of optimum working conditions. Lessons can be learned from other transport industries and it is important to seek examples of best practice and apply these in an effective way to the maritime sector. Methods of addressing issues specific to seafaring are now well developed and a holistic approach to the problem of fatigue can lead to a culture that benefits the industry as a whole.

Patterns of fatigue among seafarers during a tour of duty.

BACKGROUND: Work-related fatigue is associated with sickness absence and mental and physical health problems, and may increase the risk of accidents and injuries at work. Relatively little is known about fatigue among seafarers, particularly during a tour of duty. The aim of this study was to describe the pattern of day to day fatigue among seafarers during a tour at sea. METHODS: Participants from the offshore support, short sea and coastal, and deep sea sectors of the UK shipping industry completed daily diaries. Information about sleep and fatigue was collected each day on waking and retiring. RESULTS: Fatigue on waking was a more sensitive measure of cumulative occupational fatigue than fatigue on retiring. Fatigue on waking increased between the start and end of tour. This increase took place in particular during the first week at sea, and was most apparent among those on shorter tours of duty. CONCLUSIONS: Day to day changes in fatigue are measurable, and may vary among particular sub-groups of seafarers. Used among larger groups, such a diary method could help identify times and activities associated with the greatest risk.

SSRIs and cognitive performance in a working sample.

BACKGROUND: Studies of the impact of antidepressant use on cognitive performance have frequently been carried out among the elderly or on healthy volunteers. Comparatively little research has considered their impact on a relatively young, working population, particularly within the context of everyday life. AIMS: To examine any association between SSRI use and cognitive performance, mood and human error at work. METHODS: SSRI users and controls completed a battery of laboratory based computer tasks measuring mood and cognitive function pre- and post-work at the start and end of a working week. They also completed daily diaries reporting their work performance. RESULTS: SSRI use was associated with memory impairment: specifically poorer episodic, though not working or semantic memory. Effects of SSRI use on recognition memory seemed to vary according to the underlying psychopathology, while effects on delayed recall were most pronounced among those whose symptoms had not (yet) resolved. There were no detrimental effects on psychomotor speed, attention, mood or perceived human error at work. CONCLUSIONS: The findings lend support to the SSRIs comparative safety, even among workers, particularly as the symptoms of the underlying psychopathology are successfully addressed. Possible memory impairments may, however, be found in those taking SSRIs.

Minor injuries, cognitive failures and accidents at work: incidence and associated features.

BACKGROUND: There is a dearth of information examining minor injuries and cognitive failures in the workplace. AIMS: This study aims to describe the incidence of, and characteristics associated with, minor injuries, cognitive failures and accidents in the workplace. METHODS: The study was a community based postal questionnaire survey of people selected at random from the Electoral Registers of Cardiff and Merthyr Tydfil; 7980 questionnaires were returned. RESULTS: Frequent/very frequent minor injuries were reported by 9.8% of the workers and frequent/very frequent cognitive failures (e.g. problems of memory, attention or action) by 10.5%. Work accidents requiring treatment were reported by 5.6% of the workers. Minor injuries, cognitive failures and accidents were associated with a number of demographic and health factors. In addition, minor injuries, cognitive failures and accidents were found to be related to each other. CONCLUSIONS: A large number of workers experience accidents and minor injuries at work. Minor injuries are not recorded by official sources but could have implications in productivity and worker health. Factors identified in this study, as associated with injuries or accidents, could be addressed by specific workplace policies or by raising individual awareness of the risks.

Recreational drug use: patterns from a South Wales self-report survey.

This study aimed to examine patterns of illicit recreational drug use, alcohol consumption, and smoking in a community-based population sample. A postal questionnaire survey was conducted of people who were selected at random from the Electoral registers of Cardiff and Merthyr Tydfil. Twelve percent of respondents reported illicit recreational drug use in the last year, and 7% in the last month. Among respondents aged under 25 years, 34% (39% of males and 31% of females) had used illicit drugs in the last year, and 19% (23% of males and 17% of females) in the last month. Twenty-one percent of respondents smoked (20% of males and 22% of females). Twenty-seven percent of respondents reported drinking more alcohol than currently recommended sensible limits (36% of males and 21% of females). Among respondents aged under 25 years, 53% of men and 38% of women drank over these limits. Illicit drug use was associated with heavy alcohol consumption and, in particular, with smoking. Smoking and heavy alcohol consumption combined was most strongly associated with illicit drug use. Rates of illicit recreational drug use were higher than have previously been reported for Wales. Illicit drug use and smoking varied with age, sex, work status and geographical location, whereas heavy alcohol consumption varied with age, sex and work status, but not geographical location. Both smoking and alcohol consumption were associated with illicit drug use, with smokers who were also heavy drinkers being those most likely to report illicit drug use.

Factors associated with recreational drug use.

This study aimed to examine demographic, lifestyle, mental health and personality factors associated with illicit recreational drug use, heavy alcohol consumption and smoking in a community-based population sample. A postal questionnaire survey was conducted of people who were selected at random from the Electoral registers of Cardiff and Merthyr Tydfil. Illicit drug use was associated with risk taking, neuroticism, being male, having a higher education qualification, not being married, being unemployed, being aged under 25 years, smoking, heavy alcohol consumption and living in Cardiff. Smoking was associated with anxiety, depression, being female, lower income and educational qualifications, looking after the family or home, being aged over 25 years, illicit drug use and heavy alcohol use. Heavy alcohol consumption was associated with not being depressed, experiencing sleeping problems, risk taking, being male, higher income, no higher educational qualification, not being married, being a student, being aged under 25 years, smoking and illicit drug use. Illicit drug use, smoking and heavy alcohol use were strongly associated with each other. Illicit drug use was associated with alcohol use and, to an even greater extent, with smoking. Illicit drug and alcohol use were associated with similar characteristics, but smoking was associated with a rather different demographic combination.

Job strain, effort--reward imbalance, and stress at work: competing or complementary models?

BACKGROUND: The Demand Control Model (DCM) and the Effort Reward Imbalance Model (ERI) offer putative explanations of the relationship between stressful working conditions, job strain, and psychological and physical ill health. AIMS: The aims of this study are to: (a) compare the predictive powers of the two models for explaining perceived job stress and mental distress amongst workers as a whole, (b) identify whether a model which combines dimensions of the DCM and ERI might have more predictive power than either of them separately, and (c) ascertain whether the models make distinct contributions to explaining stress at work in specific occupational settings. METHODS: Statistical analysis was carried out on data collected from a cross-sectional postal survey of a random sample (n = 7,069), of the adult population in an urban area in Southern England. The analysis focused on the 4,135 respondents who were in paid employment. RESULTS: There was little support for combining the models as the combined model was dominated by the predictive power of dimensions from the ERI. However, the results also showed that the models or dimensions of the models made distinct contributions to explaining perceived work stress in different types of occupation. CONCLUSIONS: There is little evidence to support a combined model of work characteristics. The ERI appears to be the stronger of the two models although the DCM has explanatory value for specific occupations.

Preliminary investigation of the association between psychotropic medication use and accidents, minor injuries and cognitive failures.

RATIONALE: Psychotropic medication may impair psychomotor and cognitive function, and so increase accident susceptibility. However, few studies examine any association in the framework of other demographic, health and occupational factors. OBJECTIVES: To examine the relationship between sleeping tablets and antidepressants, and accidents, minor injuries and cognitive failures. METHODS: Postal questionnaire study of 3111 individuals who participated in an earlier phase of the Bristol Stress and Health Study. RESULTS: Sleeping tablet use was associated with accidents, minor injuries and cognitive failures both at work and outside work. Antidepressant use was associated with accidents and cognitive failures both at work and outside work. Adjusting for health, demographic and occupational factors explained many of these associations, but sleeping tablet use was independently associated with accidents (both at work and outside work), and antidepressant use with cognitive failures (outside work). CONCLUSIONS: Antidepressant and sleeping tablet use were apparently associated with accidents, minor injuries and cognitive failures. Although most of the associations could be accounted for by other factors the results suggested links between sleeping tablet use and accidents, and between antidepressant use and cognitive failures.

A contemporary validation of the Reeder Stress Inventory.

OBJECTIVES: To examine the construct validity of the RSI in a contemporary cohort. DESIGN: A cross-sectional investigation of 1,717 employed individuals who responded to the second stage of a study of occupational stress. METHODS: Scores on the RSI are compared to smoking and drinking habits, social class, and two measures of health (number of days sick leave, and number of visits to a GP during the previous year). The RSI was compared to three questionnaires measuring concepts related to stress: the 12-item General Health Questionnaire (GHQ-12), the Hospital Anxiety and Depression Scale (HADS), and the Karasek Job Strain Questionnaire. RESULTS: Higher levels of stress, as measured by the RSI, were associated with smoking a greater number of cigarettes, and, if the respondent drank alcohol, greater consumption of alcoholic drinks. High levels of stress were also associated with having taken more days sick leave, having made more frequent visits to a GP, and, somewhat unexpectedly, with being a teetotaller, and with holding a non-manual occupation. Of the questionnaire measures, the strongest association was between the RSI and HADS anxiety subscale, consistent with an overlap between the concepts of stress and anxiety. CONCLUSIONS: This study supports the construct validity of the RSI in a sample of employed individuals.