Self-Reported Early and Later Life Weight and the Risk of All-Cause Mortality in Older Adults

OBJECTIVES

The extent to which body weight in early adulthood is associated with late-life mortality risk is unclear. This study aimed to determine the association between body mass index (BMI) in early adulthood (at 18 years of age) and older age (70 years and over), and the risk of mortality in later life.

DESIGN

Secondary analysis of the ASPREE Longitudinal Study of Older Persons (ALSOP).

SETTING, PARTICIPANTS

Data were from 14,853 relatively healthy community-dwelling Australians aged ≥ 70 years when enrolled in the study.

MEASUREMENTS

Self-reported weight at age ≥ 70 years and recalled weight at age 18 years were collected at ALSOP study baseline. Height was measured with a stadiometer and was used for calculation of BMI at both timepoints. BMI at each timepoint was defined as: underweight, normal weight, overweight and obese. Individuals were categorised into one of five 'lifetime' BMI groups: normal weight (BMI between 18.5 and 24.9 at both times), overweight (25.0-29.9 at either or both times), obesity to non-obese (≥30.0 at age 18 and <30.0 ≥ 70 years), non-obese to obesity (<30.0 at age 18 and ≥30.0 at age ≥ 70 years), and early and later life obesity (≥30.0 at both times).

RESULTS

During a median 4.7 years follow-up, 715 deaths occurred. Obesity at 18 years, but not in older age (p=0.44), was significantly associated with the risk of mortality in later life, even after accounting for current health status (HR: 2.35, 95% CI: 1.53-3.58, p<0.001). Compared with participants with normal BMI at both time points, being obese at both time points was associated with increased mortality risk (HR=1.99, 95% CI: 1.04-3.81, p=0.03), and the risk was even greater for individuals who were obese at 18 years but were no longer obese in older age (HR=2.92, 95% CI: 1.65-5.16, p<0.001), in fully adjusted models. Participants who were normal weight at 18 years and were obese in later life, did not have an increased mortality risk (p=0.78).

CONCLUSIONS

Obesity in early adulthood, and obesity in both early and later life, were associated with increased mortality risk in later life. This highlights the importance of preventing obesity in early adulthood and maintaining a normal weight over an adult lifespan.

Correlates of Meal Skipping in Community Dwelling Older Adults: A Cross-Sectional Study

In this cross-sectional analysis of 10,071 community dwelling adults aged ≥70 years, we examined factors associated with meal skipping (self-reported) using multivariable logistic regression. Prevalence of meal skipping in this study was 19.5%. The adjusted odds (aOR [95%CI]) of meal skipping were lower in those 85+ years (vs. 70-74.9 years, 0.56 [0.45-0.70]), and in those in regional areas (vs. urban area, 0.81 [0.72-0.92]). Higher odds of meal skipping were observed for those living alone (vs. living with someone, 1.84 [1.64-2.05]), current smokers (vs. non-smokers, 2.07 [1.54-2.80]), consumers of high amounts of alcohol (vs. abstainers 1.93 [1.35-2.75]), those with poor oral health (vs. excellent oral health, 1.71 [1.07 -2.73]) diabetes (vs. not 1.26 [1.06-1.50]), or frailty (vs. not, 1.63 [1.09-2.43]). This study identified socio-demographic, social, behavioural and biomedical correlates of meal skipping in later life, which may assist in targeting interventions to address meal skipping.

Novel wearable and contactless heart rate, respiratory rate, and oxygen saturation monitoring devices: a systematic review and meta-analysis

We performed a systematic review and meta-analysis to identify, classify and evaluate the body of evidence on novel wearable and contactless devices that measure heart rate, respiratory rate and oxygen saturations in the clinical setting. We included any studies of hospital inpatients, including sleep study clinics. Eighty-four studies were included in the final review. There were 56 studies of wearable devices and 29 of contactless devices. One study assessed both types of device. A high risk of patient selection and rater bias was present in proportionally more studies assessing contactless devices compared with studies assessing wearable devices (p = 0.023 and p < 0.0001, respectively). There was high but equivalent likelihood of blinding bias between the two types of studies (p = 0.076). Wearable device studies were commercially available devices validated in acute clinical settings by clinical staff and had more real-time data analysis (p = 0.04). Contactless devices were more experimental, and data were analysed post-hoc. Pooled estimates of mean (95%CI) heart rate and respiratory rate bias in wearable devices were 1.25 (-0.31-2.82) beats.min^-1 (pooled 95% limits of agreement -9.36-10.08) and 0.68 (0.05-1.32) breaths.min^-1 (pooled 95% limits of agreement -5.65-6.85). The pooled estimate for mean (95%CI) heart rate and respiratory rate bias in contactless devices was 2.18 (3.31-7.66) beats.min^-1 (pooled limits of agreement -6.71-10.88) and 0.30 (-0.26-0.87) breaths.min^-1 (pooled 95% limits of agreement -3.94-4.29). Only two studies of wearable devices measured S_p O₂ ; these reported mean measurement biases of 3.54% (limits of agreement -5.65-11.45%) and 2.9% (-7.4-1.7%). Heterogeneity was observed across studies, but absent when devices were grouped by measurement modality and reference standard. We conclude that, while studies of wearable devices were of slightly better quality than contactless devices, in general all studies of novel devices were of low quality, with small (< 100) patient datasets, typically not blinded and often using inappropriate statistical techniques. Both types of devices were statistically equivalent in accuracy and precision, but wearable devices demonstrated less measurement bias and more precision at extreme vital signs. The statistical variability in precision and accuracy between studies is partially explained by differences in reference standards.

Population genomic screening of all young adults in Australia to detect familial hypercholesterolemia: a cost-effectiveness analysis

Background

Heterozygous familial hypercholesterolemia (FH) is a highly-penetrant, autosomal dominant monogenic disorder that causes elevated plasma low-density cholesterol (LDL-C) levels and risk of premature coronary heart disease (CHD). To date, the cost-effectiveness of the emerging strategy of genomic screening of adult populations for FH has not been investigated.

Purpose

To assess the impact and cost-effectiveness of offering population genomic screening to all young adults in Australia to detect heterozygous familial hypercholesterolemia (FH).

Methods

We designed a decision analysis model to compare the current standard of care for heterozygous FH diagnosis in Australia (opportunistic cholesterol screening and genetic cascade testing) with population genomic screening of adults aged 18–40 years to detect pathogenic variants in the LDLR/APOB/PCSK9 genes. The model captured morbidity/mortality due to coronary heart disease (CHD) over a lifetime horizon, from a healthcare perspective. Risk of CHD, treatment effects, prevalence, and healthcare costs were estimated from published studies. Outcomes included quality adjusted life years (QALYs), costs and incremental cost-effectiveness ratio (ICER), discounted 5% annually. Sensitivity analyses were undertaken to explore the impact of key input parameters on the robustness of the model. The model structure was designed to be transferable to countries with different healthcare systems.

Results

Over the lifetime of the population (4,167,768 men; 4,129,961 women), the model estimated a gain of 62,722 years of life lived and 73,959 QALYs due to CHD prevention. Population genomic screening for FH would be cost-effective from a healthcare perspective if the cost per test was ≤AU$300 (∼US$233) which would yield an ICER AU$28,000 cost-saving.

Conclusion

Based on our model, offering population genomic screening to all young adults to detect FH could be cost-effective in the Australian healthcare system, at testing costs that are currently feasible.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): This work was supported by the Australian National Heart Foundation and Monash University Faculty of Medicine, Nursing and Health Sciences Results from scenario analysesResults from Monte Carlo simulations

P4557Factors associated with treatment and control of hypertension in a healthy elderly population free of cardiovascular disease: a cross-sectional study

Introduction

Despite readily available treatments, control of high blood pressure (BP) in the ageing population remains suboptimal. Gaps in understanding the management of high BP amongst the elderly exist, as most studies have been in predominantly middle-aged populations.

Purpose

We explored pharmacological BP lowering treatment and control among elderly hypertensive participants free from overt cardiovascular disease (CVD), and identified factors related to both “untreated” and “treated but uncontrolled” high BP.

Methods

We analyzed baseline data from 19,114 individuals aged ≥65 years enrolled from Australia and the US in the ASPirin in Reducing Events in the Elderly (ASPREE) study. Hypertension was defined as an average systolic/diastolic BP ≥140/90 mmHg and/or use of any BP-lowering medication. `Controlled hypertensives” were those receiving BP-lowering medication and with BP <140/90 mmHg. Descriptive analyses were used to summarize hypertension control rates; logistic regression was used to investigate relationships with treatment and BP control.

Results

Overall, 74% (14,213/19,114) of participants were hypertensive, and of these 29% (4,151/14,213) were untreated. Among those treated, 47% (4,732/10,062) had BP <140/90 mmHg. Participants who were untreated were more likely to be men, have higher educational status, and be in good physical health, and less likely to have significant comorbidities. The factors related to “treated but uncontrolled” hypertension included older age, being men, Black race (versus White), using BP lowering monotherapy and residing in Australia (versus US) (Figure 1).

Conclusion(s)

There were high levels of “untreated” and “treated but uncontrolled” BP, in an otherwise healthy elderly population, suggesting that opportunities for better BP control exist through targeting intervention to high-risk individuals.

Acknowledgement/Funding

National Institute on Aging and the National Cancer Institute at NIH; NHMRC Australia, Monash University, Victorian Cancer Agency (Australia)

P6362Impact of the 2017 AHA/ACC hypertension guideline on hypertension prevalence and cardiovascular risk factors in a healthy older cohort

Background

The 2017 American Heart Association (AHA)/American College of Cardiology (ACC) hypertension guideline recommends a target blood pressure (BP) of <130/80 mmHg regardless of age, which is lower than previously recommended BP goals.

Purpose

We aimed to determine how much the updated classification for high BP would increase the overall prevalence of “hypertension” in an otherwise healthy elderly population. Additionally, we explored the cardiovascular disease (CVD) risk factor distribution in those newly classified “hypertensives” to determine whether the increased prevalence of hypertension was accompanied by an increase in other modifiable CVD risk factors.

Methods

We used baseline data from 19,114 participants (16,703 in Australia and 2,411 in the USA) aged ≥65 years who were enrolled in the ASPirin in Reducing Events in the Elderly (ASPREE) study between 2010 and 2014. Participants were classified as having hypertension using either: (a) pre-2017 thresholds (SBP ≥140 mmHg or mean DBP ≥90 mmHg and/or on anti-hypertensive) or (b) 2017 AHA/ACC guidelines (SBP ≥130 mmHg or DBP ≥80 mmHg and/or on anti-hypertensive). We assessed the presence of cardiovascular disease risk factors such as diabetes, hypercholesterolemia, smoking, obesity, reduced renal function among these hypertensive participants and also estimated their predicted risk over 10 years.

Results

Based on pre-2017 thresholds, 74% of the participants met the criteria for hypertension. Hypertension prevalence increased to 87% when the more stringent 2017 guideline was applied. 29% of this subset of newly classified hypertensive participants did not have any other identifiable traditional CVD risk factors. Further, a significantly lower 10-year predicted cardiovascular risk (22% versus 26%, p<0.001) among those newly classified hypertensive participants was observed in relation to those having hypertension based on pre-2017 guideline (Figure 1).

Figure 1. 10-year predicted CVD risk among hyoertensive and newly classified hypertensive ASPREE participants by presence of CVD risk factor

Conclusion

As expected, the prevalence of hypertension increased among the healthy elderly when applying the new AHA-2017 guideline; however, the increased prevalence occurs despite lack of an accompanying increase in additional CVD risk factors or predicted 10-year risk. Our findings suggest an individualized approach is needed in evaluating high BP among the healthy elderly.

Acknowledgement/Funding

National Institute on Aging and the National Cancer Institute at NIH; NHMRC Australia, Monash University, Victorian Cancer Agency (Australia)

Sleep and Cancer Incidence in Alberta's Tomorrow Project Cohort

We aimed to investigate the association between self-reported sleep duration and sleep timing midpoint with all- and site-specific cancer incidence in Alberta's Tomorrow Project (ATP) cohort. Methods: The analysis for sleep duration included 46,300 Albertans aged 35–65 years at baseline from the ATP cohort recruited from 2001–2015. Sleep timing midpoint (wake-time – ½ sleep duration) was assessed in a subset of ATP participants (n = 19,820). Cancer incidence was determined through record linkage with the Alberta Cancer Registry in December 2016. Cox proportional hazard regression models evaluated the effects of sleep duration and sleep timing midpoint categories on all- and site-specific (breast, colorectal, lung, prostate, endometrial and hematologic) cancer incidence. Models were adjusted for age, sex (non sex-specific cancers), highest level of education, total household income, marital status, alcohol intake, smoking status, body mass index, family history of cancer, presence of at least one medical condition/co-morbidity, menopausal status (female cancers only) and sleep duration (sleep timing midpoint analysis only). Results: By 2016, there were 3,034 incident cases of cancer in this cohort. A statistical trend was noted for an increased risk of all cancers in participants reporting &gt; 9 hours of sleep/night compared to 7–9 hours of sleep/night (hazard ratio (HR) = 1.16, 95% confidence interval (CI): 0.98–1.36; P = 0.08). Reporting &gt; 9 hours of sleep/night compared to 7–9 hours of sleep/night was also associated with an increased incidence of endometrial cancer (HR = 2.09, 95% CI: 1.16–3.76; P = 0.01). A later sleep timing midpoint (&gt;4:08 AM) versus an intermediate sleep timing midpoint (3:47 AM–4:08 AM) was associated with an increased risk of all (HR = 1.19, 95% CI: 1.03–1.37; P = 0.02) and breast (HR = 1.64, 95% CI: 1.18–2.26; P = 0.003) cancer incidence. Conclusions: These novel findings provide evidence regarding the important role of sleep in cancer etiology. Interventions that put emphasis on proper sleep hygiene for cancer prevention are needed.

Precision Measurement of the β Asymmetry in Spin-Polarized ^{37}K Decay

Using Triumf's neutral atom trap, Trinat, for nuclear β decay, we have measured the β asymmetry with respect to the initial nuclear spin in ^{37}K to be A_{β}=-0.5707(13)_{syst}(13)_{stat}(5)_{pol}, a 0.3% measurement. This is the best relative accuracy of any β-asymmetry measurement in a nucleus or the neutron, and is in agreement with the standard model prediction -0.5706(7). We compare constraints on physics beyond the standard model with other β-decay measurements, and improve the value of V_{ud} measured in this mirror nucleus by a factor of 4.

Dose–response effects of aerobic exercise on energy compensation in postmenopausal women: combined results from two randomized controlled trials

Background/objectives:

Despite the clear health benefits of exercise, exercised-induced weight loss is often less than expected. The term ‘exercise energy compensation’ is used to define the amount of weight loss below what is expected for the amount of exercise energy expenditure. We examined the dose–response effects of exercise volume on energy compensation in postmenopausal women.

Participants/methods:

Data from Alberta Physical Activity and Breast Cancer Prevention (ALPHA) and Breast Cancer and Exercise Trial in Alberta (BETA) were combined for the present analysis. The ALPHA and BETA trials were two-centred, two-armed, 12-month randomized controlled trials. The ALPHA trial included 160 participants randomized to 225 min per week of aerobic exercise, and the BETA trial randomized 200 participants to each 150 and 300 min per week of aerobic exercise. All participants were aged 50–74 years, moderately inactive (<90 min per week of exercise), had no previous cancer diagnosis and a body mass index between 22 and 40 kg m⁻². Energy compensation was based on changes in body composition (dual-energy X-ray absorptiometry scan) and estimated exercise energy expenditure from completed exercise volume. Associations between Δenergy intake, ΔVO_2peak and Δphysical activity time with energy compensation were assessed.

Results:

No differences in energy compensation were noted between interventions. However, there were large inter-individual differences in energy compensation between participants; 9.4% experienced body composition changes that were greater than expected based on exercise energy expenditure, 64% experienced some degree of energy compensation and 26.6% experienced weight gain based on exercise energy expenditure. Increases in VO_2peak were associated with reductions in energy compensation (β=−3.44 ml kg⁻¹ min⁻¹, 95% confidence interval for β=−4.71 to −2.17 ml kg⁻¹ min⁻¹; P=0.0001).

Conclusions:

Large inter-individual differences in energy compensation were noted, despite no differences between activity doses. In addition, increases in VO_2peak were associated with lower energy compensation. Future studies are needed to identify behavioral and metabolic factors that may contribute to this large inter-individual variability in energy compensation.

Emergency demand and repeat attendances by older patients

BACKGROUND

Population ageing is projected to impact on health services utilisation including Emergency Departments (ED), with older patients reportedly having a high rate of return visits. We describe and compare patterns in ED utilisation between older and younger adults, and quantify the proportion and rate of return visits.

METHODS

Population-based retrospective analysis of metropolitan Melbourne public hospital ED data, 1999/2000 to 2008/2009. Numbers of patients, presentations, re-presentations and rates per 1000 population were calculated, with comparison of older (aged ≥ 70 years) and younger (15-69 years) attendances.

RESULTS

Population growth in each age group was similar over the study period, yet ED presentations rose by 72% for older adults compared with a 59% increase for younger adults. Rates per 1000 population rose with increasing age. Of the population aged ≥ 70 years, 39% presented to ED compared with 17% of the population aged 15-69 years in 2008/2009. Twenty-seven per cent of the increase in older adult presentations was driven by a cohort who attended ≥ 4 times in 2008/2009. The number of older patients presenting ≥ 4 times doubled over the decade, contributing to 23% of all older presentations in 2008/2009. ED length of stay rose with increasing age; 69% of older adults remained in ED for ≥ 4 h compared with 39% of younger adults in 2008/2009. The number of older adult ED hospital admissions doubled over the decade.

CONCLUSIONS

Older patients are disproportionately represented among ED attendances. They also have an increasing propensity to re-present to ED, indicating a need to identify the clinical, social and health system-related risk factors for re-attendance by specific patients.

CONSORT 2010 statement: updated guidelines can improve wound care

There is a growing need to add to the evidence base in wound care. Randomised controlled trials (RCTs) are one methodological approach for this. The CONSORT statement, which provides guidance on how to conduct a rigorous RCT, was updated earlier this year. Implementation of the Consort statement will clarify to the reader what exactly was done in the RCT, to whom and when. In this way, practitioners and health-care providers can determine its validity. The Consort statement has the potential to play a crucial role in influencing the quality of research and clinical practice, and so to improve wound care. The benefits of Consort 2010 are clear; the challenge is for clinicians and researchers to use it.

Suboptimal management of cardiovascular risk factors in coronary heart disease patients in primary care occurs particularly in women

BACKGROUND

Patients with established coronary heart disease (CHD) are at the highest risk of further events. Despite proven therapies, secondary prevention is often suboptimal. General practitioners (GPs) are in an ideal position to improve secondary prevention.

AIM

To contrast management of cardiovascular risk factors in patients with established CHD in primary care to those in clinical guidelines and according to gender.

METHODS

GPs throughout Australia were approached to participate in a programme incorporating a disease management software (mdCare) program. Participating practitioners (1258 GPs) recruited individual patients whose cardiovascular risk factor levels were measured.

RESULTS

The mdCare programme included 12,509 patients (58% male) diagnosed with CHD. Their mean age was 71.7years (intra-quartile range 66-78) for men and 74years (intra-quartile range 68-80) for women. Low-density-lipoprotein cholesterol was above target levels in 69% (2032) of women compared with 58% (2487) in men (P < 0.0001). There was also a higher proportion of women with total cholesterol above target levels (76%, 3592) compared with men (57%, 3787) (P < 0.0001). In patients who were prescribed lipid-lowering medication, 53% (2504) of men and 72% (2285) of women continued to have a total cholesterol higher than recommended target levels (P < 0.0001). Overall, over half (52%, 6538) had at least five cardiovascular risk factors (55% (2914) in women and 50% (3624) in men, P < 0.0001).

CONCLUSION

This study found less intensive management of cardiovascular risk factors in CHD patients, particularly among women, despite equivalent cardiovascular risk. This study has shown that these patients have multiple risk factors where gender also plays a role.

Definitions of antiretroviral treatment failure for measuring quality outcomes

OBJECTIVES

Our aim was to compare three different definitions of treatment failure and discuss their use as quality outcome measures for a clinical service.

METHODS

Data for treatment-naïve patients who attended the Melbourne Sexual Health Centre (MSHC) between 1 January 2000 and 31 December 2008 were analysed. Definition 1 was the strict Food and Drug Administration (FDA) definition of treatment failure as determined using the time to loss of virological response (TLOVR) algorithm. Definition 2 defined treatment failure as occurring in those whose viral load never fell to <400 HIV-1 RNA copies/mL or who developed two consecutive viral loads > or =400 copies/mL on any treatment (switching or stopping treatment with a viral load <400 copies/mL was permitted). Definition 3 was the same as definition 2 except that individuals were also deemed to have failed if they stopped treatment for 6 months or longer.

RESULTS

There were 310 antiretroviral-naïve patients who started treatment in the study period. Of these, 156 [50.3%; 95% confidence interval (CI) 42.1-53.3%] experienced treatment failure under definition 1, 10 (3.2%; 95% CI 1.5-5.8%) experienced treatment failure under definition 2, and 16 (4.5%; 95% CI 2.5-7.4%) experienced treatment failure under definition 3 over the 108 months of follow-up. The probability of failing definition 1 was statistically different from the probability of failing definition 2 or 3 (P=0.01).

CONCLUSION

There were significant differences in treatment failure for the three definitions. If definition 1 were used, the outcomes would be sufficiently common to enable clinics to be compared but would be less meaningful. If definition 2 or 3 were used, the events would be too rare to enable clinics to be compared, but it would be possible to set a benchmark level of success that clinics could aim to reach.

Methodology of the Cardiovascular Health and Age-Related Maculopathy (CHARM) Study

Age-related macular degeneration (AMD) is responsible for the majority of visual impairment in the Western world. Epidemiological studies examining risk factors for AMD are needed to develop strategies for the prevention of blindness from this condition. A number of potentially modifiable risk factors for AMD have been identified; however, only smoking has been a consistent risk factor across the numerous studies. A growing body of evidence suggests that AMD and cardiovascular disease may have common risk factors. The Cardiovascular Health and Age Related Maculopathy (CHARM) Study was established to examine the risk factors for AMD and its progression, in particular risk factors associated with cardiovascular disease. Examining risk factors for prevalent AMD, cases with AMD were compared with age and gender matched controls with no AMD features. For the assessment of AMD progression, the study examined in 2001 and 2002 those participants with early AMD, or age-related maculopathy (ARM), who had undergone baseline examination between 1992 and 1995 and compared the characteristics of those who had progression of AMD with those who did not. The CHARM study involved both ophthalmic and cardiovascular examinations. Standardised clinical eye examination and grading of the macular stereo photographs were used to determine the AMD status and progression. To examine cardiovascular status, carotid artery ultrasound imaging analysis of systemic arterial compliance, augmentation index and pulse wave velocity were performed. The traditional and novel risk factors for CVD such as levels of glucose, cholesterol, high density lipoprotein cholesterol, low density lipoprotein cholesterol, fibrinogen, C-reactive protein, immunoglobulins A and M, homocysteine, oxidized LDL and the exposure to the Chlamydia Pneumonia infection were determined. DNA was collected for apolipoprotein E genotyping. The present paper outlines the primary aims of the CHARM study, the methodology involved and the recruitment results.

Assessment of an unplanned admission to the intensive care unit as a global safety indicator in surgical patients

An unplanned intensive care unit admission within 24 hours of a procedure with an anaesthetist in attendance (UIA) is a recommended clinical indicator It is designed to identify preventable iatrogenic complications. Often understood as a specific anaesthetic outcome, its value has been repeatedly questioned. Iatrogenic complications however often result from successive mishaps. In the specific context of an UIA these complications can be related both to anaesthesia and surgery. UIA is therefore probably more a global indicator of the safety of surgical care (anaesthetic and surgical) rather than a specific anaesthetic outcome. Its utility as such is however unknown. The purpose of this study was to assess the value of UIA as a global measure of avoidable iatrogenic complications in surgical patients. Using computerised patient records and medical charts, all patients with an UIA over a study period of five years were identified. The proportion, cause and preventability of iatrogenic complications amongst these patients were assessed. A total of 188 UIA patients were identified by peer reviewers. Of these, 87% to 92% had a complication caused by anaesthesia and/or surgery. Anaesthesia was found to be responsible for 24% to 31% of iatrogenic complications. All other cases related to the combination of anaesthesia and surgery or surgery alone. Of these, 74% to 92% of complications were found to be preventable. Despite intrinsic limitations of the retrospective chart review method, UIA can be considered as a valuable tool to detect avoidable iatrogenic complications related to both surgical and anaesthetic care.

Training and other predictors of personal protective equipment use in Australian grain farmers using pesticides

OBJECTIVES

To investigate patterns of use of personal protective equipment (PPE) to reduce pesticide exposure in a sample of Australian farmers and also to assess the influence of possible predictive factors.

METHODS

A cross-sectional survey of 1102 farmers recruited through the Victorian Farmers Federation (VFF) was conducted. A written questionnaire was filled out by participants at VFF meetings attended by a visiting research assistant. Participants answered questions about frequency of pesticide use and PPE items they usually used when doing two different pesticide-related tasks, mixing and application, of each of four classes of pesticides. They also answered questions about personal characteristics, farm characteristics, farming activities, career and health.

RESULTS

Nearly all surveyed farmers had ever used pesticides, and over 87% had used Herbicides or Animal Health Products in the previous 12 months. Non-use of PPE was frequently reported, with up to 10-40% of farmers routinely using no PPE at all when using pesticides. Across all pesticide classes, PPE use was higher for pesticide mixing than for application. In multivariate analyses PPE use appeared to be most strongly associated with younger age and farm chemical training.

CONCLUSIONS

PPE use across all pesticide classes was poor, indicating the possibility of clinically significant pesticide exposure in many farmers. Given that PPE use was found to be associated with farm chemical training, the authors suggest that training is likely to be an important intervention for reducing farmers' pesticide exposure. Poor uptake of farm chemical training by farmers and the aging farming workforce are causes for concern in the light of these findings.

Bispectral index monitoring to prevent awareness during anaesthesia: the B-Aware randomised controlled trial

BACKGROUND

Awareness is an uncommon complication of anaesthesia, affecting 0.1-0.2% of all surgical patients. Bispectral index (BIS) monitoring measures the depth of anaesthesia and facilitates anaesthetic titration. In this trial we determined whether BIS-guided anaesthesia reduced the incidence of awareness during surgery in adults.

METHODS

We did a prospective, randomised, double-blind, multicentre trial. Adult patients at high risk of awareness were randomly allocated to BIS-guided anaesthesia or routine care. Patients were assessed by a blinded observer for awareness at 2-6 h, 24-36 h, and 30 days after surgery. An independent committee, blinded to group identity, assessed every report of awareness. The primary outcome measure was confirmed awareness under anaesthesia at any time.

FINDINGS

Of 2463 eligible and consenting patients, 1225 were assigned to the BIS group and 1238 to the routine care group. There were two reports of awareness in the BIS-guided group and 11 reports in the routine care group (p=0.022). BIS-guided anaesthesia reduced the risk of awareness by 82% (95% CI 17-98%).

INTERPRETATION

BIS-guided anaesthesia reduces the risk of awareness in at-risk adult surgical patients undergoing relaxant general anaesthesia. With a cost of routine BIS monitoring at US16 dollars per use in Australia and a number needed to treat of 138, the cost of preventing one case of awareness in high-risk patients is about 2200 dollars.

Prism adaptation can improve contralesional tactile perception in neglect

The authors show that prismatic adaptation can reduce tactile inattention in stroke patients with unilateral neglect. Four patients with visuospatial neglect and tactile extinction underwent 10-minute application of 20 degrees right-shifting prismatic lenses during pointing. This improved contralesional tactile perception in all patients, even for a task requiring no exploration or spatial motor responses. This finding suggests a potential role for prismatic adaptation in the rehabilitation of multiple sensory modalities in patients with neglect.

Reduced frequency of high cholesterol levels among patients with intracerebral haemorrhage

To determine whether a relationship exists between high cholesterol levels and intracerebral haemorrhage (ICH) a case-control study was undertaken on 331 consecutive cases of first-episode primary ICH, verified by computed tomography, and 331 age- and sex-matched community controls. Using conditional logistic regression the adjusted odds ratio (OR) of ICH among individuals reporting a high cholesterol level was 0.45 [95% confidence interval (CI), 0.28-0.73]. A similar finding was observed when the analysis was limited to those using cholesterol-lowering drugs (OR 0.25; 95% CI, 0.08-0.80). These data provide support for an inverse relationship between high cholesterol levels and ICH. When considered together with previous findings, in which low cholesterol levels have been associated with an increased risk of haemorrhagic stroke, these data provide evidence that this inverse relationship may extend into a higher range of cholesterol values.

Predicted impact on Victoria's ambulance services of a new major trauma system

BACKGROUND

In 1999, a new major trauma system was proposed for the state of Victoria, Australia. The guidelines for the new system were aimed at delivering major trauma cases to definitive trauma care in the least time possible. The aim of the present study was to analyse the potential effect of this system on Victoria's ambulance services.

METHODS

The present study modelled the workload of major trauma cases in Victoria's ambulance service for one year pre- and post-introduction of the guidelines. Cases were analysed regarding whether their first hospital destination would change under the proposed guidelines, and, subsequently, whether they would require interhospital transport to a higher level trauma service. The impact on the ambulance services was modelled as annual changes in distances travelled due to predicted changes in hospital destinations.

RESULTS

Analysis of the predicted changes indicated that, in general, Victoria's metropolitan and rural road ambulance crews would not be greatly affected. However, some metropolitan road crews may have to travel extra distances for up to 110 cases per year. The major impact was on air retrieval crews, where the annual number of interhospital transfers is predicted to increase from approximately 150 to 330.

CONCLUSIONS

The present study demonstrated that most of the impact of a new trauma system on Victoria's ambulance services could be readily absorbed into the current workload. However, it also highlighted areas affected disproportionately within the ambulance services; in particular, air retrieval. Such studies are important to enable the effective implementation of new trauma systems.

Acceptance of a medical first-responder role by fire fighters

STUDY OBJECTIVE

In July 1998, a pilot trial which used fire fighters as medical first-responders for the first time in Australia, was implemented in Melbourne. We aimed to assess the impact of the introduction of a medical first-responder role to the fire service, on the fire fighters both professionally and personally.

METHODS

Focus groups were conducted at the fire stations located in the study area. Data from the focus groups was collated and examined for themes. The issues identified as important through the focus groups were then incorporated into a questionnaire.

RESULTS

The fire fighters located at the pilot stations involved in the first-responder programme appear to view their new role as first-responders as a positive addition to their emergency profession. Some areas of the programme were identified by this study as in need of improvement. Some aspects of the communication strategies utilised by the Fire Brigade were highly criticised. Some aspects of the support system offered by the Fire Brigade also appear to be regarded as unfavourable.

CONCLUSION

Results from this study provide useful information on professional fire fighter first-responder programmes and their impact on participating personnel. These results can be used to improve training modules, communication strategies and support services.

Effects of sediment bulk properties on erosion rates

Considerable work has been done recently on the effects of sediment bulk properties on erosion rates. From this it is known that erosion rates depend on at least the following parameters: bulk density, average particle size, particle size distribution, mineralogy, organic content, volume of gas in the sediment, salinity of the pore waters, and time after deposition. This work is reviewed and discussed here with the purpose of presenting a quantitative overview of the effects of each of these parameters. This information is then used to demonstrate a procedure for estimating erosion rates of sediments based on a knowledge of their bulk properties.

A systematic review of predictors of maintenance of normotension after withdrawal of antihypertensive drugs

BACKGROUND

The identification and treatment of hypertension in the general community has contributed to the reduction in strokes and coronary heart disease observed during the past 30 years. However, concerns have arisen that some patients may be receiving unnecessary antihypertensive drug therapy leading to wasted resources and the potential for adverse drug effects. Once therapy has been started, treating physicians have difficulty in selecting patients for withdrawal and have concerns regarding patient safety and their own legal liability.

PROCEDURES

This study reviews and consolidates information from published studies to identify known predictors of the successful maintenance of normotension after antihypertensive drug withdrawal. The predictors were identified by determining the proportion of subjects with various baseline characteristics who remained normotensive while off medication for at least 12 months. From these data we have developed a clinical algorithm to help identify patients in whom antihypertensive drug withdrawal might be considered. This may assist primary care physicians in achieving successful withdrawal of antihypertensive therapy among selected hypertensive patients.

RESULTS

The most consistent predictors identified were blood pressure (BP) (lower pretreatment, on treatment, and after withdrawal), nature of pharmacotherapy (fewer agents and lower dose), and preparedness to accept dietary intervention (weight and sodium reduction).

CONCLUSIONS

On the basis of this information, a trial of withdrawal of antihypertensive medication might be recommended for patients who have mildly elevated, uncomplicated BP that is well controlled on a single agent, and who are motivated and likely to accept lifestyle changes.

Developing an information pack for the Asian carers of people with autism spectrum disorders

An investigation is described which forms the basis for the development of an information package for the Asian carers of people with autism spectrum disorders (ASD) and learning disabilities. The results of semi-structured interviews and planning for questionnaires with three different linguistic Asian groups (Urdu, Gujarati and Bengali) are presented. The views, attitudes and awareness of autism, knowledge of support services and perceived priority of needs are analysed for the three different communities. The investigation concludes with recommendations as to whether separate information is needed by each culture or whether a single information pack can be used and presented in each language format. The possible presentation format in which the information can be produced is also discussed.

Compliance of Victorian dairy farmers with current calf rearing recommendations for control of Johne's disease

Questionnaires were posted to 800 randomly selected registered Victorian dairy farmers in 1996. Five hundred and thirty-four responses were received and analysed. Johne's disease (JD) had been diagnosed on the farm of 13.2% of respondents in the last 5 years. JD was rated second only to neonatal diarrhoea in importance as a disease of calves, even though other diseases occurred more frequently. However, there was a low level of compliance with JD control recommendations by the respondents. There was no significant difference in the number of JD control recommendations adopted by farmers between the three major Victorian regions. There was a significant difference in compliance between farms having had a diagnosed case of JD and those that had not. Although there is awareness among dairy farmers of the importance of JD, there appears to be a poor implementation of measures by farmers to prevent the spread of the disease. Current JD control recommendations and the method of information transfer to Victorian dairy farms should be reassessed to ensure that dairy heifers are reared with minimal risk of transmission of JD.

Efficacy testing of recombinant human immunodeficiency virus (HIV) gp160 as a therapeutic vaccine in early-stage HIV-1-infected volunteers. rgp160 Phase II Vaccine Investigators

A phase II efficacy trial was conducted with recombinant human immunodeficiency virus (HIV) type 1 envelope glycoprotein gp160 (rgp160) in 608 HIV-infected, asymptomatic volunteers with CD4+ cell counts >400 cells/mm3. During a 5-year study, volunteers received a 6-shot primary series of immunizations with either rgp160 or placebo over 6 months, followed by booster immunizations every 2 months. Repeated vaccination with rgp160 was safe and persistently immunogenic. Adequate follow-up and acquisition of endpoints allowed for definitive interpretation of the trial results. There was no evidence that rgp160 has efficacy as a therapeutic vaccine in early-stage HIV infection, as measured at primary endpoints (50% decline in CD4+ cell count or disease progression to Walter Reed stage 4, 5, or 6) or secondary endpoints. A transient improvement was seen in the secondary CD4 endpoint for the vaccination compared with the placebo arm, but this did not translate into improved clinical outcome.

Cross-subtype neutralizing antibodies induced in baboons by a subtype E gp120 immunogen based on an R5 primary human immunodeficiency virus type 1 envelope

Global human immunodeficiency virus type 1 (HIV-1) diversity may require engineering vaccines to express antigens representing strains prevalent in the target population of vaccine testing. The majority (90%) of incident infections in Thailand are genetic subtype E, with a small percentage of subtype B infections in the intravenous drug user populations. We have evaluated and compared the binding and HIV-1 neutralizing properties of serum antibodies induced in baboons by CHO cell-expressed monomeric gp120 derived from a CCR5-using (R5) subtype E primary HIV-1CM235 or a CXCR4-using (X4) subtype B T-cell line-adapted (TCLA) HIV-1SF2 isolate. In contrast to the subtype-specific HIV-1 neutralizing antibodies induced with recombinant HIV-1SF2 gp120 (rgp120SF2), rgp120CM235 immunization induced antibodies capable of neutralizing both subtype E and subtype B TCLA HIV-1 isolates. However, neither immunogen induced antibodies capable of neutralizing primary HIV-1 isolates. Antibody induced by rgp120CM235 preferentially bound natively folded gp120 and retained strong cross-reactivity against multiple gp120 strains within subtype E as well as subtype B. In contrast, antibody responses to rgp120SF2 were directed predominantly to linear epitopes poorly exposed on native gp120 and had more limited cross-recognition of divergent gp120. Fine epitope mapping revealed differences in antibody specificities. While both rgp120CM235 and rgp120SF2 induced antibodies to regions within C1, V1/V2, V3, and C5, unique responses were induced by rgp120CM235 to multiple epitopes within C2 and by rgp120SF2 to multiple epitopes within C3, V4, and C4. These data demonstrate that strain and/or phenotypic differences of HIV-1 subunit gp120 immunogens can substantially alter antibody binding specificities and subsequent HIV-1 neutralizing capacity.