Birthweight and the risk of childhood-onset type 1 diabetes: a meta-analysis of observational studies using individual patient data.

AIMS/HYPOTHESIS: We investigated whether children who are heavier at birth have an increased risk of type 1 diabetes. METHODS: Relevant studies published before February 2009 were identified from literature searches using MEDLINE, Web of Science and EMBASE. Authors of all studies containing relevant data were contacted and asked to provide individual patient data or conduct pre-specified analyses. Risk estimates of type 1 diabetes by category of birthweight were calculated for each study, before and after adjustment for potential confounders.Meta-analysis techniques were then used to derive combined ORs and investigate heterogeneity between studies. RESULTS: Data were available for 29 predominantly European studies (five cohort, 24 case-control studies), including 12,807 cases of type 1 diabetes. Overall, studies consistently demonstrated that children with birthweight from 3.5 to 4 kg had an increased risk of diabetes of 6% (OR 1.06 [95% CI 1.01-1.11]; p=0.02) and children with birthweight over 4 kg had an increased risk of 10% (OR 1.10 [95% CI 1.04-1.19]; p=0.003), compared with children weighing 3.0 to 3.5 kg at birth. This corresponded to a linear increase in diabetes risk of 3% per 500 g increase in birthweight (OR 1.03 [95% CI 1.00-1.06]; p=0.03). Adjustments for potential confounders such as gestational age, maternal age, birth order, Caesarean section, breastfeeding and maternal diabetes had little effect on these findings. CONCLUSIONS/INTERPRETATION: Children who are heavier at birth have a significant and consistent, but relatively small increase in risk of type 1 diabetes.

The work environment, stress and well-being.

BACKGROUND: Much recent work extending the field of job characteristics to include positive aspects of work makes the implicit assumption that the absence of negative work characteristics is equivalent to the presence of positive work characteristics. AIMS: To consider the effect sizes seen at different ends of job characteristic dimensions and to compare the impact of the presence and absence of job characteristics in association with mental health and well-being outcomes. METHODS: Data from 8755 workers were analysed to compare the impacts of the presence or absence of job characteristics (job demand, extrinsic effort and social support) in associations with both positive (job satisfaction) and negative (work-related stress) outcome measures. RESULTS: Comparable presence and absence impacts were apparent for extrinsic effort in association with work-related stress. However, in the association between job demand and work-related stress, the presence of high levels of job demand had a significantly greater impact than the absence of high levels of job demand; while in the association between social support and job satisfaction, the absence of high levels of social support had a significantly greater impact than the presence of high levels of social support. CONCLUSIONS: It is not always appropriate to assume that the absence of negative aspects of the work environment is equivalent to the presence of positive aspects.

Cannabis use, cognitive performance and mood in a sample of workers.

There are well documented acute and chronic effects of cannabis use on mental functioning. However, less is known about any effects on cognition within the context of work and everyday life. The aim of the study was to examine any association between cannabis use and cognitive performance, mood and human error at work. Cannabis 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. Cannabis use was associated with impairment in both cognitive function and mood, though cannabis users reported no more workplace errors than controls. Cannabis use was associated with lower alertness and slower response organization. In addition, users experienced working memory problems at the start, and psychomotor slowing and poorer episodic recall at the end of the working week. This pattern of results suggests two possible effects. First a 'hangover'-type effect which may increase with frequency of use. Second a subtle effect on cognitive function, perhaps more apparent under cognitive load and/or fatigue, which may increase with more prolonged use. The results also highlight the importance of the timing of testing within the context and routine of everyday life.

A community based investigation of the association between cannabis use, injuries and accidents.

There are well documented acute and chronic effects of cannabis use. However, less is known about any effects on safety within the context of work and everyday life. The aim of the study was to examine any association between cannabis use and injuries and accidents. A postal questionnaire survey was conducted among people selected at random from the electoral registers of Cardiff and Merthyr Tydfil. Cannabis use was associated with both minor injuries and accidents, particularly among those with high levels of other associated risk factors. Cannabis use was associated with a significant detrimental impact on safety. It is possible that this is linked to an amplification of other risk factors associated with accidents and injuries. This has potentially wide reaching implications particularly in the context of other work and lifestyle characteristics.

Psychotropic medication use and accidents, injuries and cognitive failures.

BACKGROUND: Psychotropic medication has the potential to impair psychomotor and cognitive function, and several medications have well documented links to increased accident and injury susceptibility. Those developed more recently have many fewer side effects. However, there is little work examining any association between psychotropic medication use and safety within the context of other demographic, health and lifestyle factors. AIMS: To examine and compare any associations between psychotropic medication use (including benzodiazepines, tricyclics and SSRIs) and accidents, injuries and cognitive failures in a community sample. METHODS: A postal questionnaire survey was conducted among people selected at random from the electoral registers of Cardiff and Merthyr Tydfil. RESULTS: Psychotropic medication use was associated with accidents, injuries and cognitive failures, particularly among those who already had higher levels of other risk factors and/or continuing mental health problems. CONCLUSIONS: The well established associations between accidents and injuries and older psychotropic medications were replicated. SSRIs, however, were relatively safer. The study also highlighted the need to consider any effect of psychotropic medication within the context of both mental health status and other factors.

The Bristol Stress and Health Study: accidents, minor injuries and cognitive failures at work.

BACKGROUND: Accidents and injuries at work account for several million working days lost each year. Cognitive failures (problems of memory, attention or action) can lead to accidents and injuries in certain contexts. AIM: This work describes the prevalence and associations of workplace accidents, minor injuries and cognitive failures reported by respondents to a follow-up postal questionnaire as part of the community-based Bristol Stress and Health Study. METHODS: Postal questionnaires were sent to 4673 people who participated in the first phase of the study (in which questionnaires were sent to individuals selected at random from the electoral roll). RESULTS: Four per cent of workers reported an accident at work, 8% reported quite or very frequent minor injuries and 13% reported quite or very frequent cognitive failures. Accidents at work were associated with being male, smoking and higher negative job characteristics. Respondents reported workplace accidents at a level similar to the overall UK rate. Accidents and minor injuries, and minor injuries and cognitive failures, shared common associations and all three outcomes were associated with each other. CONCLUSION: Information about cognitive failures is important in the study of accidents and injuries at work. In addition, negative job characteristics represent part of the context in which human error is translated into injury.