Helmets for preventing injury in motorcycle riders

Background: Motorcycle crash victims form a high proportion of those killed or injured in road traffic accidents. Injuries to the head, following motorcycle crashes, are a common cause of severe morbidity and mortality. It seems intuitive that helmets should protect against head injuries but it has been argued that motorcycle helmet use decreases rider vision and increases neck injuries. This review will collate the 'current available evidence on helmets and their impact on mortality, and head, face and neck injuries following motorcycle crashes.

Objectives: To quantify the effectiveness of wearing a motorcycle helmet in reducing mortality and head and neck injury following motorcycle crashes.

Search strategy: Databases including the Cochrane Injuries Group Specialised Register, Cochrane Central Register of Controlled Trials (The Cochrane Library issue 1,2003), MEDLINE (January 1966 to February 2003), EMBASE (January 1985 to February 2003), CINAHL (January 1982 to February 2003), IRRD (International Road Research Documentation), TRANSDOC, TRIS (Transport Research Information Service), ATRI (Australian Transport Index) (1976 to Feb 2003), Science Citation Index were searched for relevant articles. Web sites of traffic and road accident research bodies including government agencies were also searched. Reference lists from topic reviews, identified studies and bibliographies were examined for relevant articles.

Selection criteria: We considered for inclusion studies that investigated a population of motorcycle riders who had crashed, examining helmet use as an intervention and with outcomes that included one or more of the following: death, head, neck or facial injury. Studies included any that compared an intervention and control group and, therefore, included any randomised controlled trials, non-randomised controlled trials, cohort, case-control and cross-sectional studies. Ecological and case series studies were excluded.

Data collection and analysis: Two reviewers independently screened reference lists for eligible articles. Two reviewers independently assessed articles for inclusion criteria. Data were abstracted by two independent reviewers using a standard abstraction form.

Main results: Fifty-three observational studies were identified of varying quality. Despite methodological differences there was a remarkable consistency in results, particularly for mortality and head injury outcomes. Motorcycle helmets appear to reduce the risk of mortality although, due to heterogeneity in study design, an overall estimate of effect was not calculated. There was some evidence that the effect of helmets on mortality is modified by speed. Motorcycle helmets were found to reduce the risk of head injury and from five well-conducted studies the risk reduction is estimated to be 72% (OR 0.28, 95%CI 0.23,0.35). Insufficient evidence was found to estimate the effect of motorcycle helmets compared with no helmet on facial or neck injuries. However, studies of poorer quality suggest that helmets have no effect on the risk of neck injuries and are protective for facial injury. There was insufficient evidence to demonstrate whether differences in helmet type confer more or less advantage in injury reduction.

Conclusions: Motorcycle helmets reduce the risk of mortality and head injury in motorcycle riders who crash, although the former effect may be modified by other crash factors such as speed. Further well-conducted research is required to determine the effects of helmets and different helmet types on mortalIty, head, neck and facial injuries. However, the findings suggest that global efforts to reduce road traffic injuries may be facilitated by increasing helmet use by motorcyclists.

The role of omega-3 fatty acids in mood disorders

Research has established that docosahexaenoic acid (DHA), a long-chain omega-3 polyunsaturated fatty acid (PUFA), plays a fundamental role in brain structure and function. Epidemiological and cross-sectional studies have also identified a role for long-chain omega-3 PUFA, which includes DHA, eicosapentaenoic acid, and docosapentaenoic acid, in the etiology of depression. In the past ten years, there have been 12 intervention studies conducted using various preparations of longchain omega-3 PUFA in unipolar and bipolar depression. The majority of these studies administered long-chain omega-3 PUFA as an adjunct therapy. The studies have been conducted over 4 to 16 weeks of intervention and have often included small cohorts. In four out of the seven studies conducted in depressed individuals and in two out of the five studies in bipolar patients, individuals have reported a positive outcome following supplementation with ethyl-eicosapentaenoic acid or fish oil containing long-chain omega-3 PUFA. In the three trials that researched the influence of DHA-rich preparations, no significant effects were reported. The mechanisms that have been invoked to account for the benefits of long-chain omega-3 PUFA in depression include reductions in prostaglandins derived from arachidonic acid, which lead to decreased brain-derived neurotrophic factor levels and/or alterations in blood flow to the brain.

HbA1c as a screening tool for detection of type 2 diabetes: A systematic review

Aim: To assess the validity of glycated haemoglobin A1c (HbA1c) as a screening tool for early detection of Type 2 diabetes.

Methods: Systematic review of primary cross-sectional studies of the accuracy of HbA1c for the detection of Type 2 diabetes using the oral glucose tolerance test as the reference standard and fasting plasma glucose as a comparison.

Results: Nine studies met the inclusion criteria. At certain cut-off points, HbA1c has slightly lower sensitivity than fasting plasma glucose (FPG) in detecting diabetes, but slightly higher specificity. For HbA1c at a Diabetes Control and Complications Trial and UK Prospective Diabetes Study comparable cut-off point of ≥ 6.1%, the sensitivity ranged from 78 to 81% and specificity 79 to 84%. For FPG at a cut-off point of ≥ 6.1 mmol/l, the sensitivity ranged from 48 to 64% and specificity from 94 to 98%. Both HbA1c and FPG have low sensitivity for the detection of impaired glucose tolerance (around 50%).

Conclusions: HbA1c and FPG are equally effective screening tools for the detection of Type 2 diabetes. The HbA1c cut-off point of > 6.1% was the recommended optimum cut-off point for HbA1c in most reviewed studies; however, there is an argument for population-specific cut-off points as optimum cut-offs vary by ethnic group, age, gender and population prevalence of diabetes. Previous studies have demonstrated that HbA1c has less intra-individual variation and better predicts both micro- and macrovascular complications. Although the current cost of HbA1c is higher than FPG, the additional benefits in predicting costly preventable clinical complications may make this a cost-effective choice.

Modeling response rates in surveys of female sexual difficulty and dysfunction

INTRODUCTION: Studies that address sensitive topics, such as female sexual difficulty and dysfunction, often achieve poor response rates that can bias  results. Factors that affect response rates to studies in this area are not well characterized.
AIM: To model the response rate in studies investigating the prevalence of female sexual difficulty and dysfunction.
METHODS: Databases were searched for English-language, prevalence studies using the search terms: sexual difficulties/dysfunction, woman/women/female, prevalence, and cross-sectional. Studies that did not report response rates or were clinic-based were excluded. A multiple linear regression model was constructed.
MAIN OUTCOME MEASURES: Published response rates.
RESULTS: A total of 1,380 publications were identified, and 54 of these met our inclusion criteria. Our model explained 58% of the variance in response rates of studies investigating the prevalence of difficulty with desire, arousal, orgasm, or sexual pain (R(2) = 0.581, P = 0.027). This model was based on study design variables, study year, location, and the reported prevalence of each type of sexual difficulty. More recent studies (beta = -1.05, P = 0.037) and studies that only included women over 50 years of age (beta = -31.11, P = 0.007) had lower response rates. The use of face-to-face interviews was associated with a higher response rate (beta = 20.51, P = 0.036). Studies that did not include questions regarding desire difficulties achieved higher response rates than those that did include questions on desire difficulty (beta = 23.70, P = 0.034).
CONCLUSION: Response rates in prevalence studies addressing female sexual difficulty and dysfunction are frequently low and have decreased by an average of just over 1% per anum since the late 60s. Participation may improve by conducting interviews in person. Studies that investigate a broad range of ages may be less representative of older women, due to a poorer response in older age groups. Lower response rates in studies that investigate desire difficulty suggest that sexual desire is a particularly sensitive topic.

Is adiposity an under-recognized risk factor for tendinopathy? A systematic review

Objective : Tendon injuries have been reported to occur more frequently in individuals with increased adiposity. Treatment also appears to have poorer outcomes among these individuals. Our objective was to examine the extent and consistency of associations between adiposity and tendinopathy.

Methods : A systematic review of observational studies was conducted. Eight electronic databases were searched (Allied and Complementary Medicine, Biological Abstracts, CINAHL, Current Contents, EMBase, Medline, SPORTDiscus, and Web of Science) and citation tracking was performed on included reports. Studies were included if they compared adiposity between subjects with and without tendon injury or examined adiposity as a predictor of conservative treatment success.

Results : Four longitudinal cohorts, 14 cross-sectional studies, 8 case-control studies, and 2 interventional studies (28 in total) met the inclusion criteria, providing a total of 19,949 individuals. Forty-two subpopulations were identified, 18 of which showed elevated adiposity to be associated with tendon injury (43%). Sensitivity analyses indicated a clustering of positive findings among studies that included clinical patients (81% positive) and among case-control studies (77% positive).

Conclusion : Elevated adiposity is frequently associated with tendon injury. Published reports suggest that elevated adiposity is a risk factor for tendon injury, although this association appears to vary depending on aspects of study design and measurement. Adiposity is of particular interest in tendon research because, unlike a number of other reported risk factors for tendon injury, it is somewhat preventable and modifiable. Further research is required to determine if reducing adiposity will reduce the risk of tendon injury or improve the results of treatment.

Exploring optimistic and pessimistic attributions in depression-specific mood

Cognitive theories of depression include maladaptive thinking styles as depressive vulnerabilities. The hopelessness theory of depression (Abramson, Metalsky, & Alloy, 1989) particularly implicates stable and global attributions for negative events as influences upon depression. Positive event attributions are considered less influential, yet they have shown equal predictiveness to negative event attributions for depression-specific mood. Previous research has provided equivocal results largely because of cross-sectional design and modest psychometric properties of the measures. The present research aimed to: create a new instrument to measure optimistic and pessimistic attributions; test the relatedness of attributions for positive and negative events; and, clarify relationships of the scales with optimism and mood. Three studies were undertaken, all of which used structural equation modeling. Two cross-sectional studies, using 342 and 332 community participants respectively, developed and validated the Questionnaire of Explanatory Style (QES). A final longitudinal study with 250 community participants tested the predictive validity of the QES. Overall, six scales were developed, three of which were optimistic and three of which were negative. The scales were acceptable to community samples and had adequate psychometric properties. The optimistic scales were attributions for positive events and the negative scales were attributions for negative events rather than pessimistic scales. Cross-sectional results indicated that only one of the negative scales weakly directly predicted depression-specific mood, but all predicted general psychological distress. By contrast, the optimistic scales were more directly predictive of depression-specific mood, particularly the Positive Disposition scale. Longitudinal results indicated that two of the optimistic scales were the most important QES predictors of depression-specific mood two months later. The optimistic scale Positive Disposition appears most central to the prediction of both concurrent and subsequent depression-specific mood. The scale content represents explanations for positive events that are internal and stable characteristics. These may be construed as personal competencies to bring about positive outcomes. This scale is closely allied to measures of optimism. Findings affirm the importance of optimistic attributions to the understanding of depression-specific mood and provide a productive focus for therapeutic intervention and future research.

Leisure-time physical activity, inactivity and sedentary behaviours

Assesses the relationship between leisure-time physical activity and sedentary behaviours in two cross-sectional studies of adults. Behavioural choice theory was applied to gain a better understanding of people's time allocation in these behaviours. The findings show that preference, reinforcement, and barriers are potentially important factors to consider in the study of the increasing population prevalence of sedentary lifestyles.

Hysterectomy trends in australia between--2000/01 and 2004/05

Background: Hysterectomy is a major and common surgical procedure that has the potential to provide relief from ongoing gynaecological problems, but is often associated with negative impacts on health and wellbeing. Research indicates that hysterectomy rates and trends vary widely between and within countries; yet little is known about patterns in Australia.

Aims: This research aimed to describe hysterectomy rates and trends in Australia between 2000/01 and 2004/05.

Methods: This repeat cross-sectional study used routinely collected data from all hospitals in Australia. Data on all women admitted to hospital for a hysterectomy were obtained from the National Hospital Morbidity Database (2000/01–2004/05). Data were analysed by calculating population rates for each type of hysterectomy. Incidence rate ratios were calculated to assess changes over time.

Results: Hysterectomy rates in Australia declined from 34.8 per 10 000 women in 2000/01 to 31.2 per 10 000 women in 2004/05. A decline in the incidence rate for abdominal hysterectomy (from 18.7 to 15.1 per 10 000 women) and the incidence rate for concurrent oophorectomy (from 12.4 to 11.3 per 10 000 women) were also observed during this time period. At each point in time, the highest incidence rates for hysterectomy were for women aged 45–54 years.

Conclusions: Hysterectomy rates in Australia are declining over time and currently appear to be lower than most other countries. More hysterectomies are performed vaginally than in Canada, the USA, the UK and Finland and the rate of concurrent oophorectomy is less than that reported in the USA and the UK.

The high prevalence of vitamin D insufficiency across Australian populations is only partly explained by season and latitude

Background Inadequate sun exposure and dietary vitamin D intake can result in vitamin D insufficiency. However, limited data are available on actual vitamin D status and predictors in healthy individuals in different regions and by season.

Methods We compared vitamin D status [25-hydroxyvitamin D; 25(OH)D] in people < 60 years of age using data from cross-sectional studies of three regions across Australia: southeast Queensland (27°S; 167 females and 211 males), Geelong region (38°S; 561 females), and Tasmania (43°S; 432 females and 298 males).

Results The prevalence of vitamin D insufficiency (≤ 50 nmol/L) in women in winter/spring was 40.5% in southeast Queensland, 37.4% in the Geelong region, and 67.3% in Tasmania. Season, simulated maximum daily duration of vitamin D synthesis, and vitamin D effective daily dose each explained around 14% of the variation in 25(OH)D. Although latitude explained only 3.9% of the variation, a decrease in average 25(OH)D of 1.0 (95% confidence interval, 0.7–1.3) nmol/L for every degree increase in latitude may be clinically relevant. In some months, we found a high insufficiency or even deficiency when sun exposure protection would be recommended on the basis of the simulated ultraviolet index.

Conclusion Vitamin D insufficiency is common over a wide latitude range in Australia. Season appears to be more important than latitude, but both accounted for less than one-fifth of the variation in serum 25(OH)D levels, highlighting the importance of behavioral factors. Current sun exposure guidelines do not seem to fully prevent vitamin D insufficiency, and consideration should be given to their modification or to pursuing other means to achieve vitamin D adequacy.

Comparing trends in BMI and waist circumference

The nature of excess body weight may be changing over time to one of greater central adiposity. The aim of this study is to determine whether BMI and waist circumference (WC) are increasing proportionately among population subgroups and the range of bodyweight, and to examine the public health implications of the findings. Our data are from two cross-sectional surveys (the US National Health and Nutrition Examination Studies (NHANES) in 1988–1994 (NHANES III) and 2005–2006), from which we have used samples of 15,349 and 4,176 participants aged ≥20 years. Between 1988–1994 and 2005–2006 BMI increased by an average of 1.8 kg/m2 and WC by 4.7 cm (adjusted for sex, age, race-ethnicity, and education). The increase in WC was more than could be attributed simply to increases in BMI. This independent increase in WC (of on average, 0.9 cm) was consistent across the different BMI categories, sexes, education levels, and race-ethnicity groups. It occurred in younger but not older age groups. Overall in each BMI category, the prevalence of low-risk WC decreased and the prevalence of increased-risk or substantially increased-risk WC increased. These results suggest that the adverse health consequences associated with obesity may be increasingly underestimated by trends in BMI alone. Since WC is closely linked to adverse cardiovascular outcomes, it is important to know the prevailing trends in both of these parameters.

Does self monitoring of blood blucose as opposed to urinalysis provide additional benefit in patients newly diagnosed with type 2 diabetes receiving structured education? The DESMOND SMBG randomised controlled trial protocol

Background
The benefit of self-monitoring of blood glucose (SMBG) in people with type 2 diabetes on diet or oral agents other than sulphonylureas remains uncertain. Trials of interventions incorporating education about self-monitoring of blood glucose have reported mixed results. A recent systematic review concluded that SMBG was not cost-effective. However, what was unclear was whether a cheaper method of self-monitoring (such as urine glucose monitoring) could produce comparable benefit and patient acceptability for less cost.

Methods/Design
The DESMOND SMBG trial is comparing two monitoring strategies (blood glucose monitoring and urine testing) over 18 months when incorporated into a comprehensive self-management structured education programme. It is a multi-site cluster randomised controlled trial, conducted across 8 sites (7 primary care trusts) in England, UK involving individuals with newly diagnosed Type 2 diabetes.

The trial has 80% power to demonstrate equivalence in mean HbA1c (the primary end-point) at 18 months of within ± 0.5% assuming 20% drop out and 20% non-consent. Secondary end-points include blood pressure, lipids, body weight and psychosocial measures as well as a qualitative sub-study.

Practices were randomised to one of two arms: participants attend a DESMOND programme incorporating a module on self-monitoring of either urine or blood glucose. The programme is delivered by accredited educators who received specific training about equipoise. Biomedical data are collected and psychosocial scales completed at baseline, and 6, 12, and 18 months post programme. Qualitative research with participants and educators will explore views and experiences of the trial and preferences for methods of monitoring.

Discussion
The DESMOND SMBG trial is designed to provide evidence to inform the debate about the value of self-monitoring of blood glucose in people with newly diagnosed type 2 diabetes. Strengths include a setting in primary care, a cluster design, a health economic analysis, a comparison of different methods of monitoring while controlling for other components of training within the context of a quality assured structured education programme and a qualitative sub-study.

Anxiety is more common in children with asthma

Objective There are a variety of reasons why there may be an association between asthma and anxiety in children. Research into the relation between asthma and anxiety has been limited by the sole use of parent-reported or self-reported asthma symptoms to define asthma status. The objective of this study was to determine if children with physician-defined asthma are more likely to suffer anxiety than children without asthma.

Design A population-based, cross-sectional assessment, of self-reported anxiety symptoms.

Setting and participants Children aged 5–13 years from Barwon region of Victoria, Australia. Asthma status was determined by review with a paediatrician. Controls were a sample of children without asthma symptoms (matched for age, gender and school).

Outcome measure The Spence Children's Anxiety Scale (SCAS) written questionnaire. The authors compared the mean SCAS score, and the proportion of children with an SCAS score in the clinical range, between the groups.

Results Questionnaires were issued to 205 children with asthma (158 returned, response rate 77%), and 410 controls (319 returned, response rate 78%). The SCAS scores were higher in asthmatics than controls (p<0.001); and were more likely to be in the clinical range (OR=2.5, 95% CI 1.1 to 5.8, p=0.036). There was no evidence that these associations could be explained by known confounding factors.

Conclusions Children with asthma are substantially more likely to suffer anxiety than children without asthma. Future studies are required to determine the sequence of events that leads to this comorbidity, and to test strategies to prevent and treat anxiety among children with asthma.

Incidence and persistence/recurrence of women’s sexual difficulties : findings from the Australian longitudinal study of health and relationships

This study presents data on the prevalence, incidence, and persistence/recurrence of 8 sexual difficulties among women. Australian women participated in 2 computer-assisted interviews approximately 12 months apart. Analyses were based on a weighted sample of 2,252 women who were 20–64 years of age, sexually active in the past 12 months, and in the same heterosexual relationship at both interviews. Upon recruitment, two-thirds of women (66%) reported having one or more sexual difficulties. At follow-up, 36% reported a new sexual difficulty. The two highest incident difficulties were “lacking interest in having sex” (26%) and “taking too long to orgasm” (11%). In addition, 68% of women with 1 or more sexual difficulties at recruitment reported having at least 1 of these again at follow-up. Lacking interest in having sex had the highest persistence/recurrence (65%). Logistic regression modeling revealed a lower incidence of sexual difficulties among women in their 40s. Age was also a predictor of the persistence/recurrence, with persistence/recurrence most likely among older women. Tobacco and alcohol use predicted the incidence, but not persistence/recurrence, of lacking interest in sex. Health professionals need to take note of the sociodemographic groups most prone to developing and having persistent/recurrent sexual difficulties.

Youth physical activity and sedentary time and associations with cardiometabolic health

In recent years, there has been increasing interest in the effects of sedentary behaviour on children’s health, defined as sitting behaviours that require low levels of energy expenditure (≤1.5 METs).¹ There is some evidence that sedentary behaviours may be detrimental to children’s health, though the majority of associations observed are derived from cross-sectional studies examining television viewing and adiposity.² This study adds to the literature by examining cross-sectional and prospective associations between objectively measured moderate- to vigorous physical activity (MVPA) and sedentary time, and cardiometabolic risk factors in youth aged 4–18 years.