Implementation of supplemental physiotherapy following hip fracture surgery: a protocol for the process evaluation of a randomised controlled trial

BACKGROUND

Patient outcomes following low-trauma hip fracture are suboptimal resulting in increased healthcare costs and poor functional outcomes at 1 year. Providing early and intensive in-hospital physiotherapy could help improve patient outcomes and reduce costs following hip fracture surgery. The HIP fracture Supplemental Therapy to Enhance Recovery (HIPSTER) trial will compare usual care physiotherapy to intensive in-hospital physiotherapy for patients following hip fracture surgery. The complex environments in which the intervention is implemented present unique contextual challenges that may impact intervention effectiveness. This study aims to complete a process evaluation to identify barriers and facilitators to implementation and explore the patient, carer and clinician experience of intensive therapy following hip fracture surgery.

METHODS AND ANALYSIS

The process evaluation is embedded within a two-arm randomised, controlled, assessor-blinded trial recruiting 620 participants from eight Australian hospitals who have had surgery for a hip fracture sustained via a low-trauma injury. A theory-based mixed method process evaluation will be completed in tandem with the HIPSTER trial. Patient and carer semi-structured interviews will be completed at 6 weeks following hip fracture surgery. The clinician experience will be explored through online surveys completed pre- and post-implementation of intensive therapy and mapped to domains of the Theoretical Domains Framework (TDF). Translation and behaviour change success will be assessed using the Reach Effectiveness-Adoption Implementation Maintenance (RE-AIM) framework and a combination of qualitative and quantitative data collection methods. These data will assist with the development of an Implementation Toolkit aiding future translation into practice.

DISCUSSION

The embedded process evaluation will help understand the interplay between the implementation context and the intensive therapy intervention following surgery for low-trauma hip fracture. Understanding these mechanisms, if effective, will assist with transferability into other contexts and wider translation into practice.

TRIAL REGISTRATION

ACTRN 12622001442796.

Machine Vision Requires Fewer Repeat Measurements than Colorimeters for Precise Seafood Colour Measurement

The colour of seafood flesh is often not homogenous, hence measurement of colour requires repeat measurements to obtain a representative average. The aim of this study was to determine the optimal number of repeat colour measurements required for three different devices [machine vision (digital image using camera, and computer processing); Nix Pro; Minolta CR400 colorimeter] when measuring three species of seafood (Atlantic salmon, Salmo salar, n = 8; rockling, Genypterus tigerinus, n = 8; banana prawns, Penaeus merguiensis, n = 105) for raw and cooked samples. Two methods of analysis for number of repeat measurements required were compared. Method 1 was based on minimising the standard error of the mean and Method 2 was based on minimising the difference in colour over repeat measurements. Across species, using Method 1, machine vision required an average of four repeat measurements, whereas Nix Pro and Minolta required 13 and 12, respectively. For Method 2, machine vision required an average of one repeat measurement compared to nine for Nix Pro and Minolta. Machine vision required fewer repeat measurements due to its lower residual variance: 0.51 compared to 3.2 and 2.5 for Nix Pro and Minolta, respectively. In conclusion, machine vision requires fewer repeat measurements than colorimeters to precisely measure the colour of salmon, prawns, and rockling.

Effect of composition, casein genetic variants and glycosylation degree on bovine milk whipping properties

This study investigated the individual and combined effects of ĸ-Casein (ĸ-CN; AA, AB, BB), β-Casein (β-CN; A1A1, A1A2, A2A2) and high and low ratios of glycosylated ĸ-CN to total ĸ-CN, referred to as the glycosylation degree (GD), on bovine cream whipping properties. The genetic variants of individual cows were identified using reversed-phase high-performance liquid chromatography (RP-HPLC) and verified through liquid chromatography-mass spectrometry (LC-MS). A previously discovered relationship between days-in-milk and GD was validated and used to obtain high and low GD milk. Whipped creams were created through the mechanical agitation of fat standardised cream from milk of different ĸ-CN, β-CN, and GD combinations, and whipping properties (the ability to whip, overrun, whipping time and firmness) were evaluated. No significant correlation was measured in whipping properties for cream samples from milks with different ĸ-CN and β-CN genetic variants. However, 80 % of samples exhibiting good whipping properties (i.e., the production of a stiffened peak) were from milk with low GD suggesting a correlation between whipping properties and levels of glycosylation. Moreover, cream separated from skim milk of larger casein micelle size showed superior whipping properties with shorter whipping times (<5 min), and higher firmness and overrun. Milk fat globule (MFG) size, on the other hand, did not affect whipping properties. Results indicate that the GD of κ-CN and casein micelle size may play a role in MFG adsorption at the protein and air interface of air bubbles formed during whipping; hence, they govern the dynamics of fat network formation and influencing whipping properties.

HIP fracture Supplemental Therapy to Enhance Recovery (HIPSTER): a protocol for a randomised controlled trial

INTRODUCTION

Hip fractures result in substantial health impacts for patients and costs to health systems. Many patients require prolonged hospital stays and up to 60% do not regain their prefracture level of mobility within 1 year. Physical rehabilitation plays a key role in regaining physical function and independence; however, there are no recommendations regarding the optimal intensity. This study aims to compare the clinical efficacy and cost-effectiveness of early intensive in-hospital physiotherapy compared with usual care in patients who have had surgery following a hip fracture.

METHODS AND ANALYSIS

This two-arm randomised, controlled, assessor-blinded trial will recruit 620 participants who have had surgery following a hip fracture from eight hospitals. Participants will be randomised 1:1 to receive usual care (physiotherapy according to usual practice at the site) or intensive physiotherapy in the hospital over the first 7 days following surgery (two additional sessions per day, one delivered by a physiotherapist and the other by an allied health assistant). The primary outcome is the total hospital length of stay, measured from the date of hospital admission to the date of hospital discharge, including both acute and subacute hospital days. Secondary outcomes are functional mobility, health-related quality of life, concerns about falling, discharge destination, proportion of patients remaining in hospital at 30 days, return to preadmission mobility and residence at 120 days and adverse events. Twelve months of follow-up will capture data on healthcare utilisation. A cost-effectiveness evaluation will be undertaken, and a process evaluation will document barriers and facilitators to implementation.

ETHICS AND DISSEMINATION

The Alfred Hospital Ethics Committee has approved this protocol. The trial findings will be published in peer-reviewed journals, submitted for presentation at conferences and disseminated to patients and carers.

TRIAL REGISTRATION NUMBER

ACTRN12622001442796.

Development, feasibility testing, and preliminary evaluation of the Communication with an Artificial airway Tool (CAT): Results of the Crit-CAT pilot study

BACKGROUND

A purpose-built outcome measure for assessing communication effectiveness in patients with an artificial airway is needed.

OBJECTIVES

The objective of this study was to develop the Communication with an Artificial airway Tool (CAT) and to test the feasibility and to preliminary evaluate the clinical metrics of the tool.

METHODS

Eligible patients with an artificial airway in the Intensive Care Unit were enrolled in the pilot study (Crit-CAT). The CAT was administered at least twice before and after the communication intervention. Item correlation analysis was performed. Participant and family member acceptability ratings and feedback were solicited. A qualitative thematic analysis was undertaken.

RESULTS

Fifteen patients with a mean age of 53 years (standard deviation [SD]: 19.26) were included. The clinician-reported scale was administered on 50 attempts (100%) with a mean completion time of 4.5 (SD: 0.77) minutes. The patient-reported scale was administered on 46 out of 49 attempts (94%) and took a mean of 1.5 (SD: 0.39) minutes to complete. The CAT was feasible for use in the Intensive Care Unit, with patients with either an endotracheal or tracheostomy tube, whilst receiving invasive mechanical ventilation or not, and while using either verbal or nonverbal modes of communication. Preliminary establishment of responsiveness, validity, and reliability was made. The tool was acceptable to participants and their family members.

CONCLUSION

The clinician-reported and patient-reported components of the study were feasible for use. The CAT has the potential to enable quantifiable comparison of communication interventions for patients with an artificial airway. Future research is required to determine external validity and reliability.

Effect of a Fortified Biostimulant Extract on Tomato Plant Productivity, Physiology, and Growing Media Properties

The pursuit of sustainable and productive agriculture demands the exploration of innovative approaches to improve plant productivity and soil health. The utilization of natural agricultural biostimulants, such as extracts from seaweed, fish, and humus, has gained prominence as an ecological strategy to achieve this goal. In this study we investigated the effectiveness of a fortified biostimulant extract (FBE), composed of extracts from seaweed, fish, and humus, on tomato plant physiology, productivity, and growing media properties, and estimated carbon emissions associated with tomato production. The FBE was applied to the growing media of tomato plants produced in a greenhouse, in experiments over two growing seasons. The productivity assessments demonstrated that the application of FBE significantly increased tomato fruit yield by 20% and relative marketable fruit yield by 27%, and reduced estimated greenhouse gas (GHG) emissions associated with production by 29%. FBE treatment improved plant shoot and root biomass, accelerated flower and fruit set initiation, and increased chlorophyll content in leaves, resulting in enhanced plant physiology and advanced development. FBE treatment positively influenced the availability of crucial nutrients such as nitrogen, phosphorus, and iron in the growing media. FBE promoted the growth of total active microbes in the growing media, particularly the fungal population, which plays an important role in nutrient cycling and health. These findings highlight the beneficial effects of the FBE due to enhanced plant productivity and growth, improved fertility, the promotion of beneficial plant and growing media interactions, and the reduction in estimated GHG emissions.

Tracheostomy clinical practices and patient outcomes in three tertiary metropolitan hospitals in Australia

BACKGROUND

There is a paucity of literature in Australia on patient-focused tracheostomy outcomes and process outcomes. Exploration of processes of care enables teams to identify and address existing barriers that may prevent earlier therapeutic interventions that could improve patient outcomes following critical care survival.

OBJECTIVES

The objectives of this study were to examine and provide baseline data and associations between tracheostomy clinical practices and patient outcomes across three large metropolitan hospitals.

METHODS

We performed a retrospective multisite observational study in three tertiary metropolitan Australian health services who are members of the Global Tracheostomy Collaborative. Deidentified data were entered into the Global Tracheostomy Collaborative database from Jan 2016 to Dec 2019. Descriptive statistics were used for the reported outcomes of length of stay, mortality, tracheostomy-related adverse events and complications, tracheostomy insertion, airway, mechanical ventilation, communication, swallowing, nutrition, length of cannulation, and decannulation. Pearson's correlation coefficient and one-way analyses of variance were performed to examine associations between variables.

RESULTS

The total cohort was 380 patients. The in-hospital mortality of the study cohort was 13%. Overall median hospital length of stay was 46 days (interquartile range: 31-74). Length of cannulation was shorter in patients who did not experience any tracheostomy-related adverse events (p= 0.036) and who utilised nonverbal communication methods (p = 0.041). Few patients (8%) utilised verbal communication methods while mechanically ventilated, compared with 80% who utilised a one-way speaking valve while off the ventilator. Oral intake was commenced in 20% of patients prior to decannulation. Patient nutritional intake varied prior to and at the time of decannulation. Decannulation occurred in 83% of patients.

CONCLUSIONS

This study provides baseline data for tracheostomy outcomes across three large metropolitan Australian hospitals. Most outcomes were comparable with previous international and local studies. Future research is warranted to explore the impact of earlier nonverbal communication and interventions targeting the reduction in tracheostomy-related adverse events.

Implementation of offering choice of pulmonary rehabilitation location to people with COPD: a protocol for the process evaluation of a cluster randomised controlled trial

BACKGROUND

Pulmonary rehabilitation (PR) is a core component of management people with chronic obstructive pulmonary disease (COPD); yet, people with COPD face significant barriers to attending centre-based PR programs. The emergence of new models of PR, remotely delivered directly into people's homes, has the potential to improve rehabilitation access and completion by providing patients with a choice of rehabilitation location (centre or home). However, offering patients a choice of rehabilitation model is not usual practice. We are undertaking a 14-site cluster randomised controlled trial to determine whether offering choice of PR location improves rehabilitation completion rates resulting in reduced all-cause unplanned hospitalisation over 12 months. The aim of this paper is to describe the protocol for the process evaluation of the HomeBase2 trial.

METHODS

A mixed methods process evaluation, to be undertaken in real time, has been developed in accordance with UK Medical Research Council (MRC) recommendations on process evaluation of complex interventions. This protocol describes the intended use of two theoretical frameworks (RE-AIM framework (Reach; Effectiveness; Adoption; Implementation; Maintenance) and Theoretical Domains Framework (TDF)) to synthesise findings and interpret data from a combination of qualitative (semi-structured interviews) and quantitative (questionnaires, clinical outcome data, intervention fidelity) methodologies. Data will be collected at an intervention, patient and clinician level. Qualitative and quantitative data will be used to derive context-specific potential and actual barriers and facilitators to offering patients choice of rehabilitation location. Acceptability and sustainability of the intervention will be evaluated for future scale-up.

DISCUSSION

The process evaluation described here will appraise the clinical implementation of offering a choice of rehabilitation program location for people with COPD. It will identify and evaluate key factors for future scale-up and sustainability and scale-up of offering choice of pulmonary rehabilitation program model for people.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04217330 Registration date: January 3 2020.

Bushfire exposure is associated with increased pH and dark-cutting in beef longissimus thoracis at grading

To investigate if bushfire exposure is associated with increased loin pH, this study analysed temporal and geospatial data on fire incidence in South-Eastern Australia together with beef carcase quality and production records for fire affected animals (n = 451,299). Two outcomes were modelled: 1) loin pH at time of grading, and 2) the incidence of "high pH" defects (pH > 5.70). For both models, decreasing "time since closest fire" and "distance of property from closest fire" were associated with increasing loin pH and increased incidence of high pH carcases(p < 0.05 for all); interactions for "distance from the closest fire" with feed type (grain vs grass) and "days of fire exposure" with HGP (hormonal growth promotant) treatment (yes vs no) (p < 0.05 for both) indicate high pH outcomes were exacerbated in grass-fed and HGP treated cattle. It is concluded that exposure to bushfire is associated with increasing pH but the extent and magnitude of these increases are modulated by production factors.

Exploratory and confirmatory factor analysis of the questionnaire on Palliative Care for Advanced Dementia (qPAD) using a large sample of staff from Australian residential aged care homes

BACKGROUND

The Questionnaire on Palliative Care for Advanced Dementia (qPAD) is increasingly being used to assess residential aged care workers' knowledge and attitudes about palliative care for people with dementia. The qPAD developers performed an exploratory factor analysis and assessed the internal consistency using a small sample.

AIM

The aim of this study was to further assess the structural validity of the qPAD using a large sample of qPAD responses from staff who work in residential aged care homes in Australia.

METHODS

Data from 727 care staff who participated in an Australian dementia palliative care training project were used for exploratory factor analyses, assessment of internal consistency, and confirmatory factor analysis of the knowledge test and attitude scale components of the qPAD.

RESULTS

The exploratory factor analysis of the knowledge test produced a four-factor solution. One item loaded weakly, and four items had cross-loadings. Factor labels for the knowledge test were difficult to define. Factor analysis of the attitude scale produced a three-factor structure with good internal consistency-Feeling valued and part of the care team (α = 0.88), Family and team engagement (α = 0.75) and Perceptions and beliefs (α = 0.83). Confirmatory factor analysis indicated improvements in model fit were needed for both the knowledge test and attitude scale.

CONCLUSION

The findings of this factor analysis differed from the original study. The attitude scale produced a three-factor structure, but the knowledge test requires further development due to weak and cross-loadings of several items, inadequate internal consistency of factors and poor model fit.

High consumer acceptance of mutton and the influence of ageing method on eating quality

To compare the eating quality (EQ) of wet (WA) and dry aged (DA) mutton longissimus thoracis et lumborum (LTL) and semimembranosus (SM), bone-in leg and loin primals from 81 merino cull ewes were WA or DA for 14, 28, 42 or 56 days. Untrained consumers (n = 540) assessed the excised LTL and SM for EQ (tenderness, juiciness, liking of flavour and overall liking, 0-100), quality grade and respective willingness to pay (WTP). LTL scored higher than SM for EQ, P < 0.001 for all consumer sores. Mean LTL EQ scores were > 70 and mean SM EQ scores >54. Ageing method had no significant effect on LTL or SM EQ (P > 0.05 for all consumer scores). Ageing beyond 14 days improved SM and LTL tenderness. Consumers most often graded LTL and SM quality grades as "better than everyday" and "good everyday" respectively; corresponding WTP was 26.90 $AUD/kg and 18.80 $AUD/kg. Extended ageing periods improved mutton tenderness.

Perceptions of rural high school teachers - on the frontline of youth suicide

OBJECTIVE

This study aimed to investigate the perceptions and beliefs of rural high school teachers about student suicide completion in their school and their perceived self-efficacy in identification of suicidality in students (suicidal ideation, plans and behaviours).

DESIGN

A cross-sectional survey methodology.

SETTING

Gippsland and the Loddon Mallee regions of Victoria, Australia.

PARTICIPANTS

Rural high school teachers.

OUTCOME MEASURE

A survey that aimed to obtain participants' perceptions and self-reports about students who had died by suicide in their school within the last 5 years, their perceived self-efficacy in identifying suicidal students and barriers to helping students at risk.

RESULTS

Two hundred and seventy-seven rural high school teachers participated and 86% reported that a student from their school had died by suicide within the last 5 years. Sixty-five per cent believed that more than one student had died by suicide and 70% perceived they were currently aware of students experiencing suicidality in their class. Receiving professional development about suicide and obtaining help from mental health clinicians predicted perceived self-efficacy in identification of suicidality in students. Participants perceived the barriers to help students at risk included insufficient numbers of school-based mental health professionals and community mental health services.

CONCLUSIONS

Many rural high school teachers perceive they are at the front line of the youth suicide crisis due to unmet service need in youth mental ill health. Increased access to effective services immediately after teachers become aware of suicidality may assist in reducing youth suicide in rural areas.

Implementing a choice of pulmonary rehabilitation models in chronic obstructive pulmonary disease (HomeBase2 trial): protocol for a cluster randomised controlled trial

INTRODUCTION

There is compelling evidence that either centre-based or home-based pulmonary rehabilitation improves clinical outcomes in chronic obstructive pulmonary disease (COPD). There are known health service and personal barriers which prevent potentially eligible patients from accessing the benefits of pulmonary rehabilitation. The aim of this hybrid effectiveness-implementation trial is to examine the effects of offering patients a choice of pulmonary rehabilitation locations (home or centre) compared with offering only the traditional centre-based model.

METHOD AND ANALYSIS

This is a two-arm cluster randomised, controlled, assessor-blinded trial of 14 centre-based pulmonary rehabilitation services allocated to intervention (offering choice of home-based or centre-based pulmonary rehabilitation) or control (continuing to offer centre-based pulmonary rehabilitation only), stratified by centre-based programme setting (hospital vs non-hospital). 490 participants with COPD will be recruited. Centre-based pulmonary rehabilitation will be delivered according to best practice guidelines including supervised exercise training for 8 weeks. At intervention sites, the home-based pulmonary rehabilitation will be delivered according to an established 8-week model, comprising of one home visit, unsupervised exercise training and telephone calls that build motivation for exercise participation and facilitate self-management. The primary outcome is all-cause, unplanned hospitalisations in the 12 months following rehabilitation. Secondary outcomes include programme completion rates and measurements of 6-minute walk distance, chronic respiratory questionnaire, EQ-5D-5L, dyspnoea-12, physical activity and sedentary time at the end of rehabilitation and 12 months following rehabilitation.Direct healthcare costs, indirect costs and changes in EQ-5D-5L will be used to evaluate cost-effectiveness. A process evaluation will be undertaken to understand how the choice model is implemented and explore sustainability beyond the clinical trial.

ETHICS AND DISSEMINATION

Alfred Hospital Ethics Committee has approved this protocol. The trial findings will be published in peer-reviewed journals, submitted for presentation at conferences and disseminated to patients across Australia with support from national lung charities and societies.

TRIAL REGISTRATION NUMBER

NCT04217330.

Prevalence of failure of passive immunity transfer in Australian non-replacement dairy calves

Failure of passive immunity transfer (FPIT) increases the risk of morbidity and mortality in dairy calves. The prevalence of FPIT in dairy calves has generally been reported to be high, with FPIT estimated to occur in 38%–42% of Australian dairy calves. However, the focus of previous studies has been on replacement heifer calves. Our aim was to assess the prevalence of FPIT in Victorian bobby calves (non‐replacement dairy calves). We collected blood samples from 3608 bobby calves at three abattoirs at exsanguination, and measured serum total protein as an indicator of passive transfer. We found that 36% of bobby calves showed evidence of FPIT (serum total protein ≤52 g/L), and 50% of calves had poor or fair passive transfer (<58 g/L). When a subset of calves (from farms with more than five calves in the dataset) was analysed using a linear mixed model, Jersey calves and crossbred/other calves had an estimated 5.3 g/L and 5.1 g/L higher serum total protein concentration, respectively, than Holstein‐Friesian calves (P < 0.001). Our results suggest that the prevalence of FPIT in bobby calves at abattoirs is similar to that reported in dairy heifer calves sampled on farms. A high prevalence of FPIT has implications for bobby calf morbidity and mortality, as well as calf viability and profitability for dairy‐beef production.

Evaluation of IMproving Palliative care Education and Training Using Simulation in Dementia (IMPETUS-D) a staff simulation training intervention to improve palliative care of people with advanced dementia living in nursing homes: a cluster randomised controlled trial

Background

People with dementia have unique palliative and end-of-life needs. However, access to quality palliative and end-of-life care for people with dementia living in nursing homes is often suboptimal. There is a recognised need for nursing home staff training in dementia-specific palliative care to equip them with knowledge and skills to deliver high quality care.

Objective

The primary aim was to evaluate the effectiveness of a simulation training intervention (IMPETUS-D) aimed at nursing home staff on reducing unplanned transfers to hospital and/or deaths in hospital among residents living with dementia.

Design

Cluster randomised controlled trial of nursing homes with process evaluation conducted alongside.

Subjects & setting

One thousand three hundred four people with dementia living in 24 nursing homes (12 intervention/12 control) in three Australian cities, their families and direct care staff.

Methods

Randomisation was conducted at the level of the nursing home (cluster). The allocation sequence was generated by an independent statistician using a computer-generated allocation sequence.

Staff from intervention nursing homes had access to the IMPETUS-D training intervention, and staff from control nursing homes had access to usual training opportunities. The predicted primary outcome measure was a 20% reduction in the proportion of people with dementia who had an unplanned transfer to hospital and/or death in hospital at 6-months follow-up in the intervention nursing homes compared to the control nursing homes.

Results

At 6-months follow-up, 128 (21.1%) people with dementia from the intervention group had an unplanned transfer or death in hospital compared to 132 (19.0%) residents from the control group; odds ratio 1.14 (95% CI, 0.82-1.59). There were suboptimal levels of staff participation in the training intervention and several barriers to participation identified.

Conclusion

This study of a dementia-specific palliative care staff training intervention found no difference in the proportion of residents with dementia who had an unplanned hospital transfer. Implementation of the intervention was challenging and likely did not achieve adequate staff coverage to improve staff practice or resident outcomes.

Trial registration

Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12618002012257. Registered 14 December 2018.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-02809-x.

Patient-caregiver dyads advance care plan value discussions: randomised controlled cancer trial of video decision support tool

OBJECTIVE

Uptake of advance care planning (ACP) in cancer remains low. An emphasis on personal value discussions and adoption of novel interventions may serve as the catalyst to increase engagement. This study examined the effectiveness of a video decision support tool (VDST) modelling values conversations in cancer ACP.

METHODS

This single site, open-label, randomised controlled trial allocated patient-caregiver dyads on a 1:1 ratio to VDST or usual care (UC). Previously used written vignettes were converted to video vignettes using standard methodology. We evaluated ACP document completion rates, understanding and perspectives on ACP, congruence in communication and preparation for decision-making.

RESULTS

Participants numbered 113 (60.4% response rate). The VDST did not improve overall ACP document completion (37.7% VDST; 36.7% UC). However, the VDST improved ACP document completion in older patients (≥70) compared with younger counterparts (<70) (OR=0.308, 95% CI 0.096 to 0.982, p=0.047), elicited greater distress in patients (p=0.015) and improved patients and caregivers ratings for opportunities to discuss ACP with health professionals. ACP improved concordance in communication (VDST p=0.006; UC p=0.045), more so with the VDST (effect size: VDST 0.7; UC 0.54). Concordance in communication also improved in both arms with age.

CONCLUSION

The VDST failed to improve ACP document completion rates but highlighted that exploring core patient values may improve concordance in patient-caregiver communication. Striving towards a more rigorous design of the VDST intervention, incorporating clinical outcome scenarios with values conversations may be the catalyst needed to progress ACP towards a more fulfilling process for those who partake in it.

TRIAL REGISTRATION NUMBER

ACTRN12620001035910.

Elevated levels of circulating mitochondrial DNA predict early allograft dysfunction in patients following liver transplantation

BACKGROUND AND AIM

The role of circulating mitochondrial DNA (cmtDNA) in transplantation remains to be elucidated. cmtDNA may be released into the circulation as a consequence of liver injury; yet recent work also suggests a causative role for cmtDNA leading to hepatocellular injury. We hypothesized that elevated cmtDNA would be associated with adverse events after liver transplantation (LT) and conducted an observational cohort study.

METHODS

Twenty-one patients were enrolled prospectively prior to LT.

RESULTS

Postoperative complications were observed in 47.6% (n = 10). Seven patients (33.3%) had early allograft dysfunction (EAD), and six patients (28.5%) experienced acute cellular rejection within 6 months of LT. cmtDNA levels were significantly elevated in all recipients after LT compared with healthy controls and preoperative samples (1 361 937 copies/mL [IQR 586 781-3 399 687] after LT; 545 531 copies/mL [IQR 238 562-1 381 015] before LT; and 194 562 copies/mL [IQR 182 359-231 515] in healthy controls) and returned to normal levels by 5 days after transplantation. cmtDNA levels were particularly elevated in those who developed EAD in the early postoperative period (P < 0.001). In all patients, there was initially a strong overall positive correlation between cmtDNA and plasma hepatocellular enzyme levels (P < 0.05). However, the patients with EAD demonstrated a second peak in cmtDNA at postoperative day 7, which did not correlate with liver function tests.

CONCLUSIONS

The early release of plasma cmtDNA is strongly associated with hepatocellular damage; however, the late surge in cmtDNA in patients with EAD appeared to be independent of hepatocellular injury as measured by conventional tests.

Home-based pulmonary rehabilitation early after hospitalisation in COPD (early HomeBase): protocol for a randomised controlled trial

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is characterised by exacerbations of respiratory disease, frequently requiring hospital admission. Pulmonary rehabilitation can reduce the likelihood of future hospitalisation, but programme uptake is poor. This study aims to compare hospital readmission rates, clinical outcomes and costs between people with COPD who undertake a home-based programme of pulmonary rehabilitation commenced early (within 2 weeks) of hospital discharge with usual care.

METHODS

A multisite randomised controlled trial, powered for superiority, will be conducted in Australia. Eligible patients admitted to one of the participating sites for an exacerbation of COPD will be invited to participate. Participants will be randomised 1:1. Intervention group participants will undertake an 8-week programme of home-based pulmonary rehabilitation commencing within 2 weeks of hospital discharge. Control group participants will receive usual care and a weekly phone call for attention control. Outcomes will be measured by a blinded assessor at baseline, after the intervention (week 9-10 posthospital discharge), and at 12 months follow-up. The primary outcome is hospital readmission at 12 months follow-up.

ETHICS AND DISSEMINATION

Human Research Ethics approval for all sites provided by Alfred Health (Project 51216). Findings will be published in peer-reviewed journals, conferences and lay publications.

TRIAL REGISTRATION NUMBER

ACTRN12619001122145.

Differences in Hedonic Responses, Facial Expressions and Self-Reported Emotions of Consumers Using Commercial Yogurts: A Cross-Cultural Study

Hedonic scale testing is a well-accepted methodology for assessing consumer perceptions but is compromised by variation in voluntary responses between cultures. Check-all-that-apply (CATA) methods using emotion terms or emojis and facial expression recognition (FER) are emerging as more powerful tools for consumer sensory testing as they may offer improved assessment of voluntary and involuntary responses, respectively. Therefore, this experiment compared traditional hedonic scale responses for overall liking to (1) CATA emotions, (2) CATA emojis and (3) FER. The experiment measured voluntary and involuntary responses from 62 participants of Asian (53%) versus Western (47%) origin, who consumed six divergent yogurt formulations (Greek, drinkable, soy, coconut, berry, cookies). The hedonic scales could discriminate between yogurt formulations but could not distinguish between responses across the cultural groups. Aversive responses to formulations were the easiest to characterize for all methods; the hedonic scale was the only method that could not characterize differences in cultural preferences, with CATA emojis displaying the highest level of discrimination. In conclusion, CATA methods, particularly the use of emojis, showed improved characterization of cross-cultural preferences of yogurt formulations compared to hedonic scales and FER.

Relationship of Established Cardiovascular Risk Factors and Peripheral Biomarkers on Cognitive Function in Adults at Risk of Cognitive Deterioration

BACKGROUND

There is a paucity of information on the role of microvascular and inflammatory biomarkers in cognitive dysfunction.

OBJECTIVE

This study sought to evaluate the relationships between established and a number of peripheral biomarkers on cognitive patterns in 108 older adults with memory complaints.

METHODS

Participants in the AIBL Active study aged 60 years and older with at least one vascular risk factor and memory complaints completed a neuropsychological test battery and provided cross-sectional health data. Linear regression models adjusted for covariates examined associations between cognitive performance and a panel of vascular risk factors (Framingham cardiovascular scores, hs-CRP, homocysteine, fasting glucose, LDL-cholesterol) and peripheral biomarkers (TNF-α, BDNF, VCAM-1, ICAM-1, PAI-1, CD40L).

RESULTS

Higher fasting glucose and homocysteine levels were independent factors associated with poorer performance in Trail Making Test (TMT) B (adjusted β= 0.40±0.10 and 0.43±0.09, respectively). Increasing homocysteine levels were weakly associated with poorer global cognition and delayed recall (adjusted β= 0.23±0.10 and -0.20±0.10 respectively). Increasing Framingham cardiovascular scores were related to poorer performance in TMT B (β  = 0.42±0.19). There was early evidence of associations between increasing plasma TNF-α and poorer TMT B (adjusted β  = 0.21±0.10) and between increasing BDNF and better global cognition (β= -0.20±0.09).

CONCLUSION

This study provides evidence to support the associations between vascular risk factors (Framingham scores, fasting glucose, and homocysteine) and poorer cognitive functions. Additionally, we measured several peripheral biomarkers to further investigate their associations with cognition. The relationship between TNF-α, BDNF, and cognitive performance in various domains may offer new insights into potential mechanisms in vascular cognitive impairment.

Blood parameters of young calves at abattoirs are related to distance transported and farm of origin

Nonreplacement dairy calves, or bobby calves, are fasted and transported to abattoirs from as young as 5 d of age in Australia. The aims of this cross-sectional observational study were (1) to assess the welfare status, as measured by blood parameters, of bobby calves in the commercial supply chain after transport and lairage, and (2) to assess whether distance and duration of transport are risk factors for poor bobby calf welfare, as measured by blood parameters. We hypothesized that bobby calves transported greater distances would be more likely to show evidence of compromised welfare, as measured by blood indicators of hydration, energy status, and muscle fatigue or damage. We also hypothesized that there would be a large amount of variability in indicators of energy status between calves from different farms. We analyzed blood samples collected at slaughter over a spring and an autumn calving period from 4,484 Australian bobby calves aged approximately 5 to 14 d old from 3 different states, after transport, fasting, and lairage. Packed cell volume (PCV), plasma glucose, and serum urea, total protein, β-hydroxybutyrate (BHB), and creatine kinase (CK) were measured. Radio frequency identification ear tag data were used to estimate the distance that the calves were transported and to identify the farm of origin. Data were analyzed using linear mixed models, except for BHB, which was analyzed using a Goodman-Kruskal gamma test due to left censoring of the data. Twelve percent of calves showed evidence of anemia (PCV less than 0.23 L/L), and 11% had urea concentrations consistent with dehydration (urea more than 7.7 mmol/L). Thirty-six percent of calves had CK activity above normal resting values, and 1% of calves had CK >2,000 U/L, indicating muscle fatigue or damage. Distance transported had significant effects on all blood variables except urea and BHB. With increasing distance transported, calves were more likely to show evidence of a negative energy balance (low plasma glucose) or dehydration (high PCV or total protein). The estimated effect of distance overall was small, but for calves transported more than 500 km, plasma glucose concentration declined more per kilometer. The calves' farm of origin accounted for a reasonable amount of the random variation between calves for plasma glucose (20%). Our results suggest that longer transport distances may increase the risk of poor calf welfare (dehydration, negative energy balance) after transport, and on-farm calf management (e.g., nutrition, timing of feeding before transport) may affect transported calves' energy status; improving this area could result in better energy availability during fasting.

The effects of feeding nitrate on the development of methaemoglobinaemia in sedentary Bos indicus cattle

Context Nitrate salts can be utilised by the rumen bacteria as a nitrogen source. Nitrate salts can induce a methaemoglobinaemia in cattle if consumed in sufficient quantities. Methaemoglobinaemia is the principal factor that leads to the onset of clinical signs for nitrate toxicity in cattle. A methaemoglobin concentration ≥20% is considered unsafe for cattle. There are, however, limited studies on the longer-term effects of nitrate supplementation on methaemoglobin formation in Bos indicus steers consuming forage that is reflective of northern Australia’s poor quality, native pasture in the dry season. Aims We hypothesised that the Australian government’s recommended daily dose of nitrate salts given to Bos indicus cattle would not cause a methaemoglobinaemia in the blood &gt;20% throughout a 70 day treatment period. Methods A 70 day study was conducted to determine the methaemoglobin, carboxyhaemoglobin, total haemoglobin, growth rate and forage intakes of cattle supplemented with a non-protein-nitrogen treatment containing nitrate (6.48 g NO3/kg dry matter intake (DMI) or no nitrate and consuming a chaffed Flinders grass hay (Iseilema spp.), a C4 species. The dose rate of nitrate was selected to match the Australian government guidelines. Ten 3-year-old fistulated Bos indicus steers (mean liveweight ± s.d., 400.7 ± 26.2 kg) were randomly allocated into two groups (n = 5). Blood samples were collected at 0, 2, 4 and 6 h after treatment with nitrate or no nitrate on days 10, 30, 50 and 70 to measure haemoglobin fractions in the blood. Key Results Nitrate treatment caused the mean methaemoglobin (P &lt; 0.001), peak methaemoglobin (P &lt; 0.001) and carboxyhaemoglobin (P = 0.008) concentration to be greater in the blood of steers compared with steers given no nitrate. Nitrate treatment had no general effect on the total haemoglobin, DMI or bodyweight of steers. Conclusions Bos indicus steers treated with 6.48 g NO3/kg DMI develop a methaemoglobinaemia that does not exceed 20% of total haemoglobin for 70 days. This data supports the Australian government’s recommended feeding rate of nitrate to sedentary Bos indicus steers. Implications The Australian government’s method for feeding nitrate to cattle is safe under the conditions of this study.

The effect of molasses nitrate lick blocks on supplement intake, bodyweight, condition score, blood methaemoglobin concentration and herd scale methane emissions in Bos indicus cows grazing poor quality forage

Context The Australian government has approved a greenhouse gas (GHG) offset method that requires cattle to consume nitrate in the form of a lick block. Field studies demonstrating the effectiveness of this methodology have not been previously reported. Aims This experiment was conducted to determine the effects on productivity and health when nitrate lick blocks were provided as a supplement to grazing beef cattle. We hypothesised that beef cattle given access to nitrate lick blocks would have similar productivity compared with cattle offered urea lick blocks. Methods Bos indicus breeding cows (n = 76) grazed a 467-ha paddock near Charters Towers, Queensland, between May and November 2014. A two-way remote automatic drafting system enabled allocation of cattle to different treatments while grazing in a common paddock. Treatments were 30% urea lick blocks (30U), or molasses nitrate lick blocks (MNB). At monthly intervals liveweight (LW), body condition score (BCS), and blood methaemoglobin concentration were recorded. Estimates of individual supplement intake were made on three separate occasions using a lithium marker technique. Results Mean daily supplement intake (±s.e.m.) of 30U (122 ± 13 g) was greater (P &lt; 0.001) than MNB (67 ± 8 g). Lesser MNB intake was associated with greater variability for individual supplement intake, a greater proportion of non-consumers of supplement during July (P &lt; 0.05) and reduced voluntary supplement intake until October (P &lt; 0.001). Increasing MNB consumption during October and November was accompanied by elevated blood methaemoglobin concentration (P &lt; 0.001). It was estimated that cattle offered MNB had insufficient supplementary nitrogen intake throughout the study to resolve rumen degradable nitrogen deficiency from grazed forage. Consequently, cattle provided access to MNB demonstrated conceptus free liveweight loss and lesser BCS compared with cattle treated with 30U (P &lt; 0.001). Conclusion Nitrate lick blocks were ineffective as a dual-purpose non-protein nitrogen supplement and methane mitigant for beef cattle grazing poor quality forage. Further field experiments are required to determine if there may be situations where this GHG offset methodology is efficacious. Implications Caution is advised in implementing GHG mitigation methods that involve the use of nitrate lick blocks.

Bias Correction in Estimating Proportions by Imperfect Pooled Testing

In the estimation of proportions by pooled testing, the MLE is biased. Hepworth and Biggerstaff (JABES, 22:602-614, 2017) proposed an estimator based on the bias correction method of Firth (Biometrika 80:27-38, 1993) and showed that it is almost unbiased across a range of pooled testing problems involving no misclassification. We now extend their work to allow for imperfect testing. We derive the estimator, provide a Newton-Raphson iterative formula for its computation and test it in situations involving equal or unequal pool sizes, drawing on problems encountered in plant disease assessment and prevalence estimation of mosquito-borne viruses. Our estimator is highly effective at reducing the bias for prevalences consistent with the pooled testing procedure employed.

Ambulatory oxygen for treatment of exertional hypoxaemia in pulmonary fibrosis (PFOX trial): a randomised controlled trial

INTRODUCTION

Interstitial lung diseases are characterised by scarring of lung tissue that leads to reduced transfer of oxygen into the blood, decreased exercise capacity and premature death. Ambulatory oxygen therapy may be used to treat exertional oxyhaemoglobin desaturation, but there is little evidence to support its efficacy and there is wide variation in clinical practice. This study aims to compare the clinical efficacy and cost-effectiveness of ambulatory oxygen versus ambulatory air in people with fibrotic interstitial lung disease and exertional desaturation.

METHODS AND ANALYSIS

A randomised, controlled trial with blinding of participants, clinicians and researchers will be conducted at trial sites in Australia and Sweden. Eligible participants will be randomised 1:1 into two groups. Intervention participants will receive ambulatory oxygen therapy using a portable oxygen concentrator (POC) during daily activities and control participants will use an identical POC modified to deliver air. Outcomes will be assessed at baseline, 3 months and 6 months. The primary outcome is change in physical activity measured by number of steps per day using a physical activity monitor (StepWatch). Secondary outcomes are functional capacity (6-minute walk distance), health-related quality of life (St George Respiratory Questionnaire, EQ-5D-5L and King's Brief Interstitial Lung Disease Questionnaire), breathlessness (Dyspnoea-12), fatigue (Fatigue Severity Scale), anxiety and depression (Hospital Anxiety and Depression Scale), physical activity level (GENEActive), oxygen saturation in daily life, POC usage, and plasma markers of skeletal muscle metabolism, systematic inflammation and oxidative stress. A cost-effectiveness evaluation will also be undertaken.

ETHICS AND DISSEMINATION

Ethical approval has been granted in Australia by Alfred Hospital Human Research Ethics Committee (HREC/18/Alfred/42) with governance approval at all Australian sites, and in Sweden (Lund Dnr: 2019-02963). The results will be published in peer-reviewed scientific journals, presented at conferences and disseminated to consumers in publications for lay audiences.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT03737409).

Compartmental fat distribution in the abdomen of dogs relative to overall body fat composition

Background

Adipose tissue may have different metabolic and endocrine functions depending on the region of the body in which it is located. While visceral or intra-abdominal fat has been found to contribute to leptin concentrations, insulin resistance and obesity-related diseases, there are only a few imaging studies documenting the preferential distribution of body fat to either the intra-abdominal or subcutaneous compartments in dogs. This study aimed to determine if CT-measured abdominal fat distributed preferentially to the visceral space (V) relative to the subcutaneous space (SQ), with increasing DXA-determined total body fat percentage; and if ultrasound measurements of the ventral midline subcutaneous (SAT) and visceral adipose thickness (VAT) can be used to estimate the distribution of fat to the subcutaneous and visceral abdominal spaces, in a sample of 22 dogs with variable body condition.

Results

Multivariate analysis showed no statistically significant correlation between visceral to subcutaneous fat ratio (V/SQ) and increasing total body fat percentage (β = − 0.07, p = 0.733), but strong correlation with age (β = 0.71 p = 0.002). A substantial amount of variation for the ultrasound visceral adipose thickness to subcutaneous fat thickness (VAT/SAT) could be explained by both CT V/SQ and sex (R²_Adjusted = 0.477, p = 0.001), with female dogs having significant lower VAT/SAT ratios compared to the male dogs (p = 0.047). The ultrasound fat measurements appeared moderately reliable, but a larger sample number is required to confirm this.

Conclusions

The findings suggest that dogs with a relatively healthy to slightly overweight body condition score, distribute fat relatively similarly between their peritoneal (visceral) and subcutaneous abdominal compartments with increasing total body fat percentage. However, there was increased fat distribution to the peritoneal space relative to the subcutaneous space with increasing age. Further, abdominal ultrasound may be useful in estimating the ratio of fat distribution to both the abdominal visceral and subcutaneous spaces.

Improved irritability, mood, and quality of life following introduction of perampanel as late adjunctive treatment for epilepsy

OBJECTIVE

The objective of this study was to evaluate the efficacy and tolerability of perampanel (PER) in late adjunctive treatment of focal epilepsy. We assessed outcomes 1) according to patients' clinical profiles and the broad mechanism of action (MoA) of concomitant antiepileptic drugs (AEDs) and 2) the effects of PER on adverse events, irritability, mood, and quality of life (QOL).

METHODS

Consecutive patients commenced on PER at two epilepsy centers in Melbourne, Australia were identified. A nested cohort underwent detailed prospective assessment, while the remainder were retrospectively analyzed. Six- and 12-month efficacy endpoints were at least a 50% reduction in seizure frequency (responders) and complete seizure freedom. The prospective cohort underwent standardized validated questionnaires at 0, 1, 3, 6, and 12 months using the modified semi-structured seizure interview (SSI), Liverpool Adverse Events Profile (LAEP), Quality of Life in Epilepsy-Patient-Weighted (QOLIE-10-P), Neurological Disorders Depression Inventory Epilepsy (NDDI-E), and an Irritability Questionnaire.

RESULTS

One hundred sixty patients were followed for a median of 6 months: the mean number of prior AEDs was 6, 99% had drug-resistant epilepsy, and 72% had never experienced a prior seizure-free period of at least 6 months (=continuously refractory epilepsy). Perampanel was associated with responder and seizure freedom rates of 30.6% and 9.4% at 6 months and 19.4% and 4.4% (5.6% adjusted for the titration period) at 12 months. Having "continuously refractory epilepsy" was associated with a reduced likelihood of seizure freedom at 6 months (5% vs. 30%; p = 0.001) and 12 months (3% vs. 13%; p = 0.058). Quality of Life in Epilepsy-Patient-Weighted, irritability, and NDDI-E showed mean improvement at 6 months from baseline.

SIGNIFICANCE

Even when used as late add-on adjunctive therapy in patients with highly refractory focal epilepsy, PER can result in 12-month seizure freedom of 5.6%. The likelihood of seizure freedom was associated with prior "continuous medication refractoriness". Six months after introduction of PER patients reported improved mood, QOL, and decreased irritability.

Association between Cognitive Function and Clustered Cardiovascular Risk of Metabolic Syndrome in Older Adults at Risk of Cognitive Decline

OBJECTIVES

Metabolic syndrome (MetS) represents a cluster of obesity and insulin resistance-related comorbidities. Abdominal obesity, hypertension, elevated triglyceride and glucose levels are components of MetS and may have a negative effect on cognitive function, but few cognitive studies have examined the combined risk severity. We sought to determine which specific cognitive abilities were associated with MetS in older adults at risk of cognitive decline.

DESIGN

Cross-sectional study.

PARTICIPANTS

108 AIBL Active participants with memory complaints and at least one cardiovascular risk factor.

MEASUREMENTS

Cardiovascular parameters and blood tests were obtained to assess metabolic syndrome criteria. The factors of MetS were standardized to obtain continuous z-scores. A battery of neuropsychological tests was used to evaluate cognitive function.

RESULTS

Higher MetS z-scores were associated with poorer global cognition using ADAS-cog (adjusted standardized beta=0.26, SE 0.11, p<0.05) and higher Trail Making B scores (adjusted beta=0.23, SE 0.11, p<0.05). Higher MetS risk was related to lower cognitive performance.

CONCLUSION

Combined risk due to multiple risk factors in MetS was related to lower global cognitive performance and executive function. A higher MetS risk burden may point to opportunities for cognitive testing in older adults as individuals may experience cognitive changes.

Falls in paediatric Charcot-Marie-Tooth disease: a 6-month prospective cohort study

OBJECTIVE

To prospectively study falls in children and adolescents with Charcot-Marie-Tooth disease (CMT).

DESIGN

Prospective cohort study.

SETTING

Neuromuscular outpatient clinic of a tertiary paediatric hospital.

PATIENTS

Sixty children and adolescents ('children') aged 4-18 years, 30 with CMT and 30 typically developing (TD).

MAIN OUTCOME MEASURES

Falls rate over 6 months and falls characteristics questionnaire.

RESULTS

Twenty-two children with CMT reported falling at least once in 6 months compared with eight TD children (CMT 2819 (0-1915), TD 31 (0-6) total falls (range)). Detailed falls characteristics were collected from 242 individual falls (CMT 216, TD 26). Injurious falls were reported by 19 children with CMT (74 falls) compared with 2 TD children (3 falls), with cuts, grazes and bruising most common. No fractures were sustained and no child required hospitalisation. However, 12 injuries from falls in children with CMT required management by a healthcare provider, versus none in TD children. Tripping was the most common mechanism of falls in both groups. Age was the strongest predictor of falls (ρ=-0.53, p=0.006) with all children (CMT and TD) aged <7 years falling. Balance was the strongest impairment-related predictor of falls (ρ=-0.47, p=0.02). The conservative estimate of risk of falls in children and adolescents with CMT was 33 times higher than their TD peers (incidence rate ratio=32.8, 95% CI 10.2 to 106.0).

CONCLUSIONS

Children and adolescents with CMT fall more often than TD peers and sustain more injuries when they fall.

Abdominal volume computed tomography assessment of body composition in dogs

Background

Computed tomography (CT) has been used to estimate body composition and determine tissue distribution in dogs, despite limited validation. This may introduce error into estimates of body composition studies and its effect on health in dogs. Further, the modality has not been validated against dual-energy X-ray absorptiometry (DXA) or over a wide range of dog breeds, ages and sexes. The objective of this study was to validate the use of semi-automated, abdominal volume CT for estimating total body composition of dogs relative to DXA. Twenty-two staff-owned dogs (weighing between 5.1-60 kg) were sedated and underwent full body DXA scan and abdominal CT. Abdominal tissue composition was estimated by CT using semi-automated volume segmentation, over predetermined tissue Hounsfield threshold values. Abdominal tissue composition determined by the various CT threshold ranges was compared to total body composition determined by DXA.

Results

Abdominal tissue composition estimated by CT strongly correlated with the estimates derived from DXA with a small Bland-Altman mean percentage differences in values: total body mass (− 250/2000HU: r² = 0.985; − 1.10%); total fat mass (− 250/-25HU: r² = 0.981; − 1.90%); total lean tissue mass (− 25/150HU: r² = 0.972; 3.47%); and total bone mineral content (150/2000HU: r² = 0.900; − 0.87%). Although averaged CT values compared well to DXA analysis, there was moderate variation in the individual predicted values. There was near perfect inter- and intra-observer agreement in segmentation volumes for abdominal fat.

Conclusions

Abdominal volume computed tomography (CT) accurately and reliably estimates total body composition in dogs, but greater variations may be observed in dogs weighing less than 10 kg.

Efficacy and tolerability of adjuvant lacosamide: The role of clinical characteristics and mechanisms of action of concomitant AEDs

OBJECTIVE

The objective of this study was to analyze the effectiveness and long-term tolerability of adjuvant lacosamide (LCM) in a multicenter cohort. We aim to assess outcomes of LCM-containing antiepileptic drug (AED) combinations based upon 'mechanism of action' (MoA) and patient's clinical features.

METHODS

Consecutive patients commenced on LCM, with focal epilepsy were identified from three Australian hospitals. The 12-month efficacy endpoints were greater than 50% reduction in seizure frequency (responders) and seizure freedom. Tolerability endpoints were cessation of LCM for any reason, cessation due to side-effects and censoring due to inefficacy. Outcomes were assessed according to concomitant AEDs according to their MoA and the clinical risk factor profile.

RESULTS

Three hundred ten patients were analyzed and followed for median 17.3months. Two hundred ninety-nine (97%) had drug-resistant epilepsy, and 155 (50%) had tried more than 7 AEDs at LCM commencement. Adjuvant LCM was associated with responder and seizure freedom rate of 29% and 9% respectively at 12months. Lower baseline seizure frequency, a prior 6-month period of seizure freedom at any time since epilepsy diagnosis and being on fewer concomitant AEDs were predictive of 12-month seizure freedom. Previous focal to bilateral tonic-clonic seizures (FBTCS), lower baseline seizure frequency, and concomitant AED reduction after LCM commencement were associated with improved LCM tolerability. No specific MoA AED combinations offered any efficacy or tolerability advantage.

SIGNIFICANCE

Adjuvant LCM is associated with seizure freedom rates of 9% at 12months after commencement and is predicted by lower prior seizure frequency, a period of 6months or longer of seizure freedom since diagnosis and fewer concomitant AEDs. While the broad MoA of concomitant AEDs did not influence efficacy or tolerability outcomes, we have provided a framework that may be utilized in future studies to help identify optimal synergistic AED combinations.

Nitrate supplementation has marginal effects on enteric methane production from Bos indicus steers fed Flinders grass (Iseilema spp.) hay, but elevates blood methaemoglobin concentrations

This experiment has quantified the methane abatement potential of nitrate in the context of extensively managed cattle. The experimental protocol consisted of two, 4 × 4 Latin square design using eight rumen fistulated Bos indicus steers fed Flinders grass (Iseilema spp.) hay ad libitum. The treatments were Control (nil nitrogen supplement), urea (32.5 g/day urea) and two levels of calcium nitrate: CaN1 and CaN2 (to provide 4.6 g and 7.9 g NO3/kg DM equivalent to ~0.46% and 0.80% of DM, respectively). Complete supplement intake was ensured by dosing any supplement that had not been voluntarily consumed, through the rumen fistula, 1 h after feeding. Enteric methane production was measured using open circuit respiration chambers. Methane yield (g/kg DM intake) from the CaN2 treatment tended to be lower (P < 0.07) than either the Control or urea treatments. There were no significant differences in methane yield between Control, urea or CaN1 treatments. Mean blood methaemoglobin concentrations were significantly (P < 0.001) higher for CaN2 animals compared with the Control, urea or CaN1 treatments. In addition, a significant time effect after dosing (P < 0.001) and a significant interaction between treatment and time after dosing (P < 0.001) was apparent. Overall mean total volatile fatty acid concentration was 74.0 ± 1.53 mM with no significant treatment effect, but a significant effect for both time of sampling (3 h vs 6 h) within days and among 7 sampling days. The inclusion of calcium nitrate as a non-protein-N source significantly reduced the molar proportions of butyrate (P < 0.001), iso-butyrate (P < 0.05) and iso-valerate (P < 0.001) compared with the Control. The provision of nitrate supplements, providing both a NPN and an alternative sink for H that would otherwise support enteric methanogenesis, has some potential. In extensive grazing systems effective methane abatement strategies are required. The elevated concentration of MetHb using CaN2 suggests that the strategy of replacing urea with nitrate in supplements fed to extensively managed cattle in the northern rangelands may be inappropriate where supplement intake cannot be controlled on an individual animal basis and forage quality is seasonally variable.

Bias Correction in Estimating Proportions by Pooled Testing

In the estimation of proportions by pooled testing, the MLE is biased, and several methods of correcting the bias have been presented in previous studies. We propose a new estimator based on the bias correction method introduced by Firth (Biometrika 80:27-38, 1993), which uses a modification of the score function, and we provide an easily computable, Newton-Raphson iterative formula for its computation. Our proposed estimator is almost unbiased across a range of problems, and superior to existing methods. We show that for equal pool sizes the new estimator is equivalent to the estimator proposed by Burrows (Phytopathology 77:363-365, 1987). The performance of our estimator is examined using pooled testing problems encountered in plant disease assessment and prevalence estimation of mosquito-borne viruses.

The effect of feeding frequency and dose rate of nitrate supplements on blood haemoglobin fractions in Bos indicus cattle fed Flinders grass (Iseilemia spp.) hay

Twelve Bos indicus steers (liveweight ± s.d., 317.8 ± 28.5) kg were used in an experiment to examine two factors: daily nitrate dose (0, 30, 40 or 50 g of nitrate/day) and feeding frequency (once or twice a day) on methaemoglobin concentration, daily peak methaemoglobin concentration, rate of incline for methaemoglobin concentration, carboxyhaemoglobin concentration, oxyhaemoglobin concentration, total haemoglobin concentration, haematocrit and dry matter intake of Flinders grass hay. Increasing the dose rate of nitrate increased the fraction of methaemoglobin in the blood of steers (P = 0.014). A highly significant effect was demonstrated for the interaction of dose rate × day (P < 0.001). For once a day intake of nitrate, the dose rates of 40 and 50 g per day showed a greater increase in mean methaemoglobin values than for the 0 and 30 g of nitrate per day. Increasing the dose rate of nitrate also increased the daily peak methaemoglobin fraction and the rate of incline to peak methaemoglobin values for both once and twice a day feeding of the nitrate supplements. However, increasing the dose of nitrate had no significant overall effect on total haemoglobin, deoxyhaemoglobin, carboxyhaemoglobin, haematocrit or dry matter intake. Twice a day feeding of nitrate decreased the formation of methaemoglobin in the blood of Bos indicus steers. This study demonstrates that caution should be exercised when feeding nitrates as a non-protein nitrogen source to cattle grazing low quality pastures in northern Australia.

Shoot Injury Increases the Level of Persistence of Salmonella enterica Serovar Sofia and Listeria innocua on Cos Lettuce and of Salmonella enterica Serovar Sofia on Chive

Minor shoot injury significantly (P < 0.05) increased the level at which Salmonella enterica serovar Sofia persisted on cos lettuce in the greenhouse. Initial mean counts of the Salmonella on the injured and uninjured cos lettuce were on the order of 6 log CFU/g. After 3 days, the mean count decreased to 4.8 log CFU/g on the injured plants compared with the significantly (P < 0.05) smaller count of 3.4 log CFU/g on the uninjured plants. By the end of the 3-week experiment, the count from the injured plants was 2.9 log CFU/g compared with a count of below the level of detection from the uninjured plants. A similar pattern of bacterial persistence was observed on injured versus uninjured plants by using Listeria innocua on cos lettuce and S. enterica serovar Sofia on chive. The findings reaffirm earlier results with Escherichia coli and increase the impetus to avoid shoot injury during the production of cos lettuce and chive, if bacteria of food safety concern are present.