The Precision Toxicology Initiative

The goal of PrecisionTox is to overcome conceptual barriers to replacing traditional mammalian chemical safety testing by accelerating the discovery of evolutionarily conserved toxicity pathways that are shared by descent among humans and more distantly related animals. An international consortium is systematically testing the toxicological effects of a diverse set of chemicals on a suite of five model species comprising fruit flies, nematodes, water fleas, and embryos of clawed frogs and zebrafish along with human cell lines. Multiple forms of omics and comparative toxicology data are integrated to map the evolutionary origins of biomolecular interactions, which are predictive of adverse health effects, to major branches of the animal phylogeny. These conserved elements of adverse outcome pathways (AOPs) and their biomarkers are expect to provide mechanistic insight useful for regulating groups of chemicals based on their shared modes of action. PrecisionTox also aims to quantify risk variation within populations by recognizing susceptibility as a heritable trait that varies with genetic diversity. This initiative incorporates legal experts and collaborates with risk managers to address specific needs within European chemicals legislation, including the uptake of new approach methodologies (NAMs) for setting precise regulatory limits on toxic chemicals.

Incisional hernia following colorectal cancer surgery according to suture technique: Hughes Abdominal Repair Randomized Trial (HART)

BACKGROUND

Incisional hernias cause morbidity and may require further surgery. HART (Hughes Abdominal Repair Trial) assessed the effect of an alternative suture method on the incidence of incisional hernia following colorectal cancer surgery.

METHODS

A pragmatic multicentre single-blind RCT allocated patients undergoing midline incision for colorectal cancer to either Hughes closure (double far-near-near-far sutures of 1 nylon suture at 2-cm intervals along the fascia combined with conventional mass closure) or the surgeon's standard closure. The primary outcome was the incidence of incisional hernia at 1 year assessed by clinical examination. An intention-to-treat analysis was performed.

RESULTS

Between August 2014 and February 2018, 802 patients were randomized to either Hughes closure (401) or the standard mass closure group (401). At 1 year after surgery, 672 patients (83.7 per cent) were included in the primary outcome analysis; 50 of 339 patients (14.8 per cent) in the Hughes group and 57 of 333 (17.1 per cent) in the standard closure group had incisional hernia (OR 0.84, 95 per cent c.i. 0.55 to 1.27; P = 0.402). At 2 years, 78 patients (28.7 per cent) in the Hughes repair group and 84 (31.8 per cent) in the standard closure group had incisional hernia (OR 0.86, 0.59 to 1.25; P = 0.429). Adverse events were similar in the two groups, apart from the rate of surgical-site infection, which was higher in the Hughes group (13.2 versus 7.7 per cent; OR 1.82, 1.14 to 2.91; P = 0.011).

CONCLUSION

The incidence of incisional hernia after colorectal cancer surgery is high. There was no statistical difference in incidence between Hughes closure and mass closure at 1 or 2 years.

REGISTRATION NUMBER

ISRCTN25616490 (http://www.controlled-trials.com).

POS0083-PARE DRIVING IMPROVEMENT IN AXIAL SPONDYLOARTHRITIS SERVICES: THE USE OF QUALITY IMPROVEMENT APPROACHES AND TOOLS

Background

Quality Improvement (QI) methods have been used in healthcare since the late 1980s across a wide range of healthcare settings. However, in the UK they have not been applied widely within rheumatology including axial Spondyloarthritis (axial SpA). In 2017, the UK healthcare regulator, NICE, produced a national clinical guideline for axial SpA, but there was no mechanism to encourage uptake of its recommendations.

The National Axial Spondyloarthritis Society created a programme to use QI approaches to help encourage uptake of the Guidelines and act as a catalyst for wider improvement in axial SpA care.

Objectives

To encourage service improvement in axial Spondyloarthritis care through the use of quality improvement theory and methods.

Methods

In late 2019 six rheumatology departments were selected to participate in the first cohort. The programme design was underpinned by:

• A framework for management grounded in systems theory1

• A learning system that brings healthcare organisations together2

• A set of tools to develop, test and implement changes: the Model for Improvement3.

The teams met four times for training in QI methods, plus team-based online coaching. They had time to develop their projects and networking opportunities to share their data and experiences of implementation.

We conducted a qualitative review of the programme in year one. We interviewed 31 programme participants and reviewed programme documentation.

Results

The review found that:

•A proven QI framework provides a strong basis to build improvement

•A competitive programme helps foster motivation and accountability

•The programme provides the time to use tools to understand the problem and construct improvement aims

•Measurement is key to understand improvement and to create a story of change

•Collaboration and engagement is key within the team and with other stakeholders.

The teams have:

Conclusion

Despite the challenges of posed by the Covid-19 pandemic, a structured QI programme has enabled clinicians to stay engaged and implement projects to reduce diagnostic delay and improve care.

References

[1]Deming WE. The new economics for industry. Government, Education, Massachusetts Institute of Technology, Cambridge, MA. 1993;1:235.

[2]Institute for Healthcare Improvement. The Breakthrough Series: IHI’s Collaborative Model for Achieving Breakthrough Improvement. IHI Innovation Series white paper. Boston: Institute for Healthcare Improvement. 2003.

[3]Langley GJ, Nolan KM, Nolan TW, Norman L, Provost LP. The improvement guide. San Francisco: Jossey–Bass. 1996.

Disclosure of Interests

Dale Webb Grant/research support from: Grant funding from AbbVie, Biogen, Lilly, Janssen, Novartis & UCB, Rosie Barnett: None declared, Lucy Davies: None declared

POS0936 DISEASE TRAJECTORIES OF AXIAL SPONDYLOARTHRITIS PATIENTS INITIATED ON BIOLOGIC DMARDs: PRELIMINARY ANALYSIS FROM A REAL-WORLD COHORT

Background

The number of biologic/targeted synthetic (b/ts) disease-modifying anti-rheumatic drugs (DMARDs) available for the treatment of axial spondyloarthritis (axSpA) are increasing. However, 1 in 4 axSpA patients may discontinue their first bDMARD within the first 12-months (1). A greater understanding of real-world axSpA disease/treatment trajectories pre- and post-bDMARD initiation is needed to inform optimal treatment for patients.

Objectives

To explore the use of biologic therapies in patients living with axSpA, and estimate the natural progression of disease and patient reported measures pre- and post- initiation of first bDMARD.

Methods

Data was extracted from the Bath SpA Research Biobank for all bio-naïve axSpA patients initiated on bDMARDs between 7th March 2000 and 1st February 2021. Patients were grouped based on first bDMARD. Linear regression models were used to explore changes in Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), and Bath Ankylosing Spondylitis Functional Index (BASFI) over time; from 36-months before first bDMARD initiation, to 36-months after initiation. Changes in BASDAI/BASFI were estimated using piecewise mixed-effects linear regression. Models included fixed terms for age, sex, HLA-B27 status and disease duration. Switches to a second bDMARD and reasons for switching were captured.

Results

In total, 282 axSpA patients were included, and grouped into 3 cohorts based on first bDMARD: adalimumab (46.1%), etanercept (30.9%), other (23.1%; 6.4% certolizumab pegol, 5.0% golimumab, 5.3% infliximab, 0.7% rituximab, 5.7% secukinumab). Mean age at diagnosis was 30.7 (SD 11.3), 69.9% of patients were male, 11.0% diagnosed with non-radiographic axSpA and 85.3% HLA-B27 positive. In the 36-month period before bDMARD initiation, patients on average had a BASDAI score of 4.50 (95% CI 4.21-4.79) and BASFI of 4.02 (95% CI 3.68-4.38), with a linear and statistically significant worsening of 0.56 (95% CI 0.43-0.68) per year for the BASDAI and 0.55 (95% CI 0.41-0.69) for the BASFI (minimally clinically important difference defined as 1.1 and 0.6 for BASDAI and BASFI, respectively (2)). Following bDMARD initiation, patients indicated a statistically significant reduction in BASDAI to 3.13 (95% CI 2.82-3.45), 3.23 (95% CI 2.83-3.63) and 3.46 (95% CI 3.04-3.88) and reductions in the BASFI to 3.22 (95% CI 2.86-3.60), 3.06 (95% CI 2.61-3.53) and 3.64 (95% CI 3.16-4.12) for those treated with adalimumab, etanercept or other biologics respectively. Reduced scores were maintained over 36-months post initiation (Figure 1). Details of first and second bDMARD are outlined in Table 1. Reasons for switching were switch to biosimilar (32.4%), intolerance (25.1%), inefficacy (22.2%), malignancy (1.9%) or other (18.4%).

Table 1.

First and second bDMARD

First bDMARDSecond bDMARDAdalimumabEtanerceptOtherAdalimumab59 (57.3%)22 (21.4%)22 (21.4%)Etanercept28 (40.6%)37 (53.6%)4 (5.8%)Other15 (48.4%)8 (25.8%)8 (25.8%)Figure 1.

Predictive margins of BASDAI and BASFI 36-months pre- and post- bDMARD initiation

A-E, Predictive margins of the BASDAI score (overall – all components, A); BASDAI Q1 fatigue (B); BASDAI average of Q2-Q4 spinal pain, joint pain, enthesitis (C); BASDAI average of Q5-Q6 morning stiffness (D); and BASFI (E).

Conclusion

In our study population, there was clinically meaningful worsening of disease activity over 36-months prior to initiation of first bDMARD, despite baseline (36-months prior to first bDMARD initiation) BASDAI exceeding the current threshold for bDMARD treatment (BASDAI≥4). A clinically meaningful and maintained improvement in disease activity was reported across all cohorts in the 36-months following first bDMARD initiation.

References

[1]Lindström et al. Arthritis Research & Therapy. 2019;21(1):128-.

[2]Kviatkovsky et al. Journal of Rheumatology. 2016;43(9):1680-6.

Disclosure of Interests

Rosie Barnett Grant/research support from: UCB, Lewis Carpenter Consultant of: Statistical consultancy for Pfizer, Charlotte Cavill: None declared, Raj Sengupta Speakers bureau: Abbvie, Biogen, Celgene, Lilly, Novartis, Roche, UCB, Consultant of: Advisory boards for Abbvie, Biogen, Lilly, Novartis, UCB, Grant/research support from: Abbvie, Celgene, Novartis, UCB

COVID-19 testing in outbreak-free care homes: what are the public health benefits?

BACKGROUND

COVID-19 care home outbreaks represent a significant proportion of COVID-19 morbidity and mortality in the UK. National testing initially focused on symptomatic care home residents, before extending to asymptomatic cohorts.

AIM

The aim was to describe the epidemiology and transmission of COVID-19 in outbreak free care homes.

METHODS

A two-point prevalence survey of COVID-19, in 34 Liverpool care homes, was performed in April and May 2020. Changes in prevalence were analysed. Associations between care home characteristics, reported infection, prevention and control interventions, and COVID-19 status were described and analysed.

FINDINGS

No resident developed COVID-19 symptoms during the study. There was no significant difference between: the number of care homes containing at least one test positive resident between the first (17.6%, 95% confidence interval (CI) 6.8-34.5) and second round (14.7%, 95% CI 5.0-31.1) of testing (p>0.99); and the number of residents testing positive between the first (2.1%, 95% CI 1.2-3.4) and second round (1.0%, 95% CI 0.5-2.1) of testing (P=0.11). Care homes providing nursing care (risk ratio (RR) 7.99, 95% CI 1.1-57.3) and employing agency staff (RR 8.4, 95% CI 1.2-60.8) were more likely to contain test positive residents. Closing residents shared space was not associated with residents testing positive (RR 2.63, 95% CI 0.4-18.5).

CONCLUSIONS

Asymptomatic COVID-19 care homes showed no evidence of disease transmission or development of outbreaks; suggesting that current infection prevention and control measures are effective in preventing transmission. Repeat testing at two to three weeks had limited or no public health benefits over regular daily monitoring of staff and residents for symptoms. These results should inform policies calling for regular testing of asymptomatic residents.

FRI0309 DAILY SELF-REPORTED FLARE PROFILES IN AXIAL SPONDYLOARTHRITIS: ASSOCIATIONS BETWEEN FLARE, SYMPTOMS AND BEHAVIOUR

Background:

Axial spondyloarthritis (axSpA) is a chronic inflammatory disease, characterised by fluctuating periods of flare and remission. Flare is a multidimensional change of disease state; whereby flare definitions have previously been formulated using validated composite indices, or through qualitative retrospective investigation of flare states. Smartphone technologies for tracking disease symptoms provide unique, daily insights into self-reported individual flare experience, and may present an opportunity to gain a more complete understanding of flare burden and symptom patterns.

Objectives:

To assess frequency and characteristics of axSpA flares, utilising data collected in the uMotif symptom tracking app.

Methods:

Patients with axSpA attending the Royal National Hospital for Rheumatic Diseases in Bath were invited to participate. Through the uMotif app, patients were sent daily reminders to log flare, pain, fatigue, sleep, recommended exercise, mood and stress using 5-point Likert scales, in addition to optional variables such as smoking and menstrual cycle. Self-reported periods of flare were identified. For each patient reporting flare within the study period, a mean ‘flare’ and ‘non-flare’ score was calculated for each variable. Paired t-tests were conducted for each variable, to investigate which variables correlate with flare status.

Results:

Between 5th April 2018 and 8th March 2019, 174 patients consented for research and logged a mean of 99.73 (SD 99.97, range 1 - 323 days) days of data. 136/174 (78%) patients recorded at least 1 flare, with 1330 flares recorded in total. For patients reporting at least 1 flare, each flare lasted a mean of 2.20 days (SD 2.53 days, range 1 – 33 days), with a mean frequency of once every 45.19 days (SD 53.06, range 3.2 -314 days). Significant relationships were identified between flare status and uMotif scores (Table 1).

Table 1.

Paired t-tests: flare vs. non-flare scores for each variable

Estimated difference^p-valueN95% CI (lower limit)95% CI (upper limit)Variable-0.870.266-2.630.88Red Painful Eyes-0.670.000*130-0.78-0.56Pain-0.570.004*25-0.94-0.20Chest Pain-0.510.005*15-0.83-0.18Hot Flushes-0.500.000*129-0.61-0.40Fatigue-0.440.1962-2.231.35Blood in Stool-0.380.000*128-0.47-0.29Mood-0.360.000*127-0.52-0.20Anti-Inflammatory Use-0.360.000*128-0.48-0.23Recommended Exercise-0.340.000*33-0.51-0.17Confidence in Self-Management-0.260.000*128-0.37-0.15Stress-0.250.17015-0.620.12Screen Time-0.190.000*130-0.26-0.12Sleep Quality-0.150.45812-0.590.28Menstrual Cycle-0.110.10322-0.250.02Eyesight0.090.1953-0.120.30Flare of Psoriasis0.050.65626-0.170.26Medication Adherence0.040.7973-0.530.61Smoking Today-0.030.48450-0.110.05Caffeine Intake

N= number of patients with both a flare and non-flare entry for each variable; CI=confidence interval

Higher variable scores indicate more positive outcomes (e.g. a higher pain score indicates less pain)

^Estimated difference between flare and non-flare entries (e.g. on average, the mean pain score of a flare entry is 0.67 [0.56– 0.78 CI] less than a non-flare entry)

*p<0.01

Conclusion:

These findings demonstrate significant relationships between a variety of patient-reported symptoms and flare, including variables that to our knowledge, have not yet been explored in axSpA. Small estimated differences were found between scores for ‘flare’ versus ‘no-flare’. Further work is needed to characterise fluctuating flare/no-flare patterns of individuals tracking daily symptoms in the uMotif app. In future research, it will be important to determine whether there is a chronological pattern of variables during the pre-flare period that can predict a flare. Greater understanding of such patterns may allow identification of the optimal timing of intervention to prevent a period of flare and improve quality of life for patients with axSpA.

Acknowledgments:

We thank UCB for funding use of the uMotif application.

Disclosure of Interests:

Rosie Barnett: None declared, Stanley Ng: None declared, Simon Jones: None declared, Matthew Young: None declared, Raj Sengupta Grant/research support from: Research grants from UCB, Pfizer, Abbvie and Novartis, Speakers bureau: Received honoraria for giving talks from Abbvie, Biogen, UCB, Novartis, Pfizer

Secular changes in functional disability, pain, fatigue and mental well-being in early rheumatoid arthritis. A longitudinal meta-analysis

OBJECTIVES

To conduct a systematic review and longitudinal meta-analysis of early rheumatoid arthritis (RA) cohorts with long-term data on pain, fatigue or mental well-being.

METHODS

Searches using PUBMED, EMBASE and PyscInfo were performed to identify all early RA cohorts with longitudinal measures of pain, fatigue or mental well-being, along with clinical measures. Using longitudinal meta-analyses, the progression of each outcome over the first 60-months was estimated. Cohorts were stratified based on the median recruitment year to investigate secular trends in disease progression.

RESULTS

Of 7,319 papers identified, 75 met the inclusion criteria and 46 cohorts from 41 publications provided sufficient data on 18,046 patients for meta-analysis. The Disease Activity Scores (DAS28) and the Short-Form 36 (SF-36) Physical Component Score (PCS) indicated that post-2002 cohorts had statistically significant improvements over the first 60-months compared to pre-2002 cohorts, with standardised mean differences (SMD) of 0.86 (95% Confidence Intervals 0.34 to 1.37) and 0.76 (95% CI 0.25 to 1.27) respectively at month-60. However, post-2002 cohorts indicated statistically non-significant improvements in pain, fatigue, functional disability and SF-36 Mental Component Score (MCS) compared to pre-2002 cohorts, with SMD of 0.24 (95% CI -0.25 to 0.74), 0.38 (95% CI -0.11 to 0.88), 0.34 (95% CI -0.15-0.84) and -0.08 (95% CI -0.41 to 0.58) at month-60 respectively.

CONCLUSIONS

Recent cohorts indicate improved levels of disease activity and physical quality of life, however this has not translated into similar improvements in levels of pain, fatigue and functional disability by 60-months.

Association between bedtime and self-reported illness among college students: a representative nationwide study of China

OBJECTIVE

This study was to examine the association between bedtime and self-reported illness among Chinese college students.

METHODS

Participants were 11,942 students, who were identified through a multistage survey sampling process. Sleep and illness status were obtained by self report. Both unadjusted and adjusted methods were considered in the analyses.

RESULTS

The logistic regression model found that late bedtime was positively associated with self reported short and long-term illness (OR: 3.70 and 1, 79) after adjusting for demographic characteristics, short sleep duration, and mental disorders.

CONCLUSIONS

This study is the first to find a positive relationship between late bedtime and self reported illnesses in China or elsewhere. The findings underscore the importance of educating college students about the importance of sleep.

A spinor Bose-Einstein condensate phase-sensitive amplifier for SU(1,1) interferometry

The SU(1,1) interferometer was originally conceived as a Mach-Zehnder interferometer with the beam-splitters replaced by parametric amplifiers. The parametric amplifiers produce states with correlations that result in enhanced phase sensitivity. F = 1 spinor Bose-Einstein condensates (BECs) can serve as the parametric amplifiers for an atomic version of such an interferometer by collisionally producing entangled pairs of |F = 1, m = ±1〉 atoms. We simulate the effect of single and double-sided seeding of the inputs to the amplifier using the truncated-Wigner approximation. We find that single-sided seeding degrades the performance of the interferometer exactly at the phase the unseeded interferometer should operate the best. Double-sided seeding results in a phase-sensitive amplifier, where the maximal sensitivity is a function of the phase relationship between the input states of the amplifier. In both single and double-sided seeding we find there exists an optimal phase that achieves sensitivity beyond the standard quantum limit. Experimentally, we demonstrate a spinor phase-sensitive amplifier using a BEC of ²³Na in an optical dipole trap. This configuration could be used as an input to such an interferometer. We are able to control the initial phase of the double-seeded amplifier, and demonstrate sensitivity to initial population fractions as small as 0.1%.

Perceptions of supported and unsupported prone-restraint positions

WHAT IS KNOWN ON THE SUBJECT?: Although the use of prone restraint should be avoided, it may remain a last resort emergency intervention for violent behaviour in psychiatric settings. However, when used as a last resort, concerns remain about the ability of staff to maintain the dignity, welfare and safety of the patient and minimize the potential adverse outcomes associated with restraint. This study builds on existing research regarding the risks of prone restraint by focusing on the psychological perceptions of individuals held in this position. WHAT THIS PAPER ADDS TO EXISTING KNOWLEDGE?: Individuals, who were asked to rate the psychological impact of two different prone-restraint positions (Supported and Unsupported Prone Positions) reported that the Supported Prone Position was more comfortable, less anxiety inducing and less limiting to breathing. Although no individual found prone restraint a positive experience, it shows that individuals found the psychological impact of the Supported Prone Position was less than the Unsupported Prone Position. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: Mental health professionals have a clear responsibility to maintain the dignity, safety and wellbeing of individuals subject to prone restraint as a short-term emergency procedure for the management of violent behaviour. Reducing both the physiological and psychological impact of prone restraint will help to reduce any adverse impact on individuals subject to such interventions. The findings will help influence current practice and promote the removal of the USPP as a specific prone-restraint intervention.

ABSTRACT

Aim Restraint-related deaths are multi-factorial with prone restraint remaining a concern due to the physiological and psychological risks. This study builds on evidence presented by (Barnett et al. Medicine, Science and the Law (2012b): 1) that the Supported Prone Position (SPP) reduces physiological risks, by examining if the SPP also reduces the psychological impact of prone restraint. Methods Twenty participants ran to near maximal exertion before being held in two prone-restraint positions: SPP and Unsupported Prone Position (USPP). Perceptions of comfort, anxiety and breathing limitation were measured using Visual Analogue Scales. Results Results showed that (1) comfort was 23% greater in the SPP; (2) anxiety was 55% less in the SPP; and (3) perception of breathing limitation was 32% less in the SPP when compared with the USPP. Negative perceptions expressed for the USPP included feeling trapped, vulnerable and concern over heart rate. Discussion In addition to reducing physiological risks, this study shows that the SPP reduced the psychological impact of prone restraint compared to USPP. Implications for Practice Settings where prone restraint cannot be avoided should remove the USPP as an emergency procedure in favour of the SPP as a way of maintaining safety and reducing the psychological impact of prone restraint.

The effective dose of different scanning protocols using the Sirona GALILEOS(®) comfort CBCT scanner

OBJECTIVES

To determine the effective dose and CT dose index (CTDI) for a range of imaging protocols using the Sirona GALILEOS(®) Comfort CBCT scanner (Sirona Dental Systems GmbH, Bensheim, Germany).

METHODS

Calibrated optically stimulated luminescence dosemeters were placed at 26 sites in the head and neck of a modified RANDO(®) phantom (The Phantom Laboratory, Greenwich, NY). Effective dose was calculated for 12 different scanning protocols. CTDI measurements were also performed to determine the dose-length product (DLP) and the ratio of effective dose to DLP for each scanning protocol.

RESULTS

The effective dose for a full maxillomandibular scan at 42 mAs was 102 ± 1 μSv and remained unchanged with varying contrast and resolution settings. This compares with 71 μSv for a maxillary scan and 76 μSv for a mandibular scan with identical milliampere-seconds (mAs) at high contrast and resolution settings.

CONCLUSIONS

Changes to mAs and beam collimation have a significant influence on effective dose. Effective dose and DLP vary linearly with mAs. A collimated maxillary or mandibular scan decreases effective dose by approximately 29% and 24%, respectively, as compared with a full maxillomandibular scan. Changes to contrast and resolution settings have little influence on effective dose. This study provides data for setting individualized patient exposure protocols to minimize patient dose from ionizing radiation used for diagnostic or treatment planning tasks in dentistry.

Spinor dynamics in an antiferromagnetic spin-1 thermal Bose gas

We present experimental observations of coherent spin-population oscillations in a cold thermal, Bose gas of spin-1 23Na atoms. The population oscillations in a multi-spatial-mode thermal gas have the same behavior as those observed in a single-spatial-mode antiferromagnetic spinor Bose-Einstein condensate. We demonstrate this by showing that the two situations are described by the same dynamical equations, with a factor of 2 change in the spin-dependent interaction coefficient, which results from the change to particles with distinguishable momentum states in the thermal gas. We compare this theory to the measured spin population evolution after times up to a few hundreds of ms, finding quantitative agreement with the amplitude and period. We also measure the damping time of the oscillations as a function of magnetic field.

Using abattoir surveillance and producer surveys to investigate the prevalence and current preventative management of Caseous lymphadenitis in Merino flocks in Australia

The prevalence of Caseous lymphadenitis (CLA) in Australia was estimated to be 5.2% using 2009 abattoir surveillance data from all States supplied by Animal Health Australia involving 5029 lines comprising 1 339 463 sheep. This is a decrease from the 26% estimated in a similar study in 1995. There was a significant difference (P < 0.001) in CLA prevalence between all states except Tasmania and Victoria (P = 0.75) with prevalences of 12.8 and 12.9%, respectively. Western Australia recorded the lowest prevalence with 1.0%. The average CLA prevalence for New South Wales was 5.3% and within three surveyed Livestock Health and Pest Authority regions (Tablelands, Central North and Central West) was 2.9, 4.9 and 4.4%, respectively. The attitude of the majority of producers surveyed in these three Livestock Health and Pest Authority areas was that CLA was of little or no significance (75%) but were aware of the need for CLA control with ~68% using 6-in-1 vaccine, though only 39.9% as recommended. It appears that the prolonged use of CLA vaccination has been successful in reducing the prevalence of CLA across Australia and particularly in New South Wales. Further improvements in communication of information on preventative management practices associated with lice control, importance of using an approved vaccination program, plus increasing producers’ awareness of the importance of CLA control, are indicated.

Design and evaluation of quantum dot sensors for making superficial x-ray energy radiation measurements

The extraordinary physical properties of quantum dot (QD) materials such as high radiation sensitivity and good radiation resistivity indicate their potential for use in the fabrication of radiation sensors. This paper reports the design and fabrication of two kinds of radiation sensors based on ZnO and CdTe QDs. Both sensors are characterized using a Gulmay Medical D3000 DXR unit for superficial x-ray irradiation with source photon energies that range from 36.9 to 64.9 keV. The QD radiation sensors exhibit excellent linearity with respect to different photon energy doses, radiation source to device surface distances, and field sizes. The effects of the electrode separation and the area density of the QD layer are also investigated. All sensors characterized show an outstanding repeatability under photon irradiation, with a signal variation less than 1%.

The neighbourhood effects of geographical access to tobacco retailers on individual smoking behaviour

OBJECTIVE

To investigate whether neighbourhood measures of geographical accessibility to outlets selling tobacco (supermarkets, convenience stores and petrol stations) are associated with individual smoking behaviour in New Zealand.

METHODS

Using geographical information systems, travel times from the population-weighted centroid of each neighbourhood to the closest outlet selling tobacco were calculated for all 38,350 neighbourhoods across New Zealand. These measures were appended to the 2002/03 New Zealand Health Survey, a national survey of 12, 529 adults. Two-level logistic regression models were fitted to examine the effects of neighbourhood locational access upon individual smoking behaviour after controlling for potential individual- and neighbourhood-level confounding factors, including deprivation and urban/rural status.

RESULTS

After controlling for individual-level demographic and socioeconomic variables, individuals living in the quartiles of neighbourhoods with the best access to supermarkets (OR 1.23, 95% CI 1.06 to 1.42) and convenience stores (OR 1.19, 95% CI 1.03 to 1.38) had a higher odds of smoking compared with individuals in the worst access quartiles. However, the association between neighbourhood accessibility to supermarkets and convenience stores was not apparent once other neighbourhood-level variables (deprivation and rurality) were included.

CONCLUSIONS

At the national level, there is little evidence to suggest that, after adjustment for neighbourhood deprivation, better locational access to tobacco retail provision in New Zealand is associated with individual-level smoking behaviour.

Sci-Thurs PM: Delivery-11: Image guidance for prostate IMRT using low dose cone beam CT

Linac-mounted cone beam computed tomography (CBCT) using Varian's On Board Imager (OBI) currently delivers significant imaging dose and lacks automatic methods for clinical target volume (CTV) registration. In this work, we address these two issues to enable frequent treatment corrections during a course of prostate intensity modulated radiation therapy (IMRT). The process starts by acquiring a low dose (low mAs) CBCT image after patient setup. The image is then used in one of two automatic image guidance strategies. The "global" technique provides the couch corrections necessary to improve patient setup by registering the CBCT to the planning CT. The "local" method involves non-rigid registration of the planning CT to the CBCT followed by automatic treatment re-optimization using the deformed planning CT and contours. Thus, the global method attempts to correct patient setup to match the planned treatment, while the local method corrects the treatment to match the patient setup. Both techniques were evaluated using images of an anthropomorphic male pelvis phantom. Global image guidance resulted in a registration error of 3.6 ± 1.3 mm (imaging dose independent) and high treatment doses to the bladder and rectum for large magnitude motion. The local technique always resulted in clinically acceptable treatment doses due to a reduced registration error of 2.3 ± 0.8 mm, obtained at 15% of the OBI's default dose (125 kVp, 2 mAs per projection). These preliminary results show that our automatic local image guidance technique reduces imaging dose and is sufficiently accurate and robust for application in prostate IMRT.

“The future of the midwife depends on her power to relieve pain”. The rise and fall of the Analgesia in Childbirth Bill (1949)

The Analgesia in Childbirth Bill (1949) remains the only attempt in British history to give mothers the legal right to pain relief in childbirth. It provides a useful introduction to the major themes in the history of British obstetric anaesthesia and analgesia under the National Health Service. This paper places the bill in the dual contexts of long-standing concern over the status of British midwives and persistent governmental squabbling over the cost of the National Health Service. For its sponsors, the National Birthday Trust Fund, the bill provided an opportunity both to improve the availability of analgesia to mothers in childbirth and to reassert their dominance as leaders in the field of analgesia research. For the Ministry of Health under a Labour Minister, Aneurin Bevan, however, the bill represented both a (concealed) Conservative attack on the newly socialized British medical system and a further burden on the already overtaxed coffers of the National Health Service. Bevan's opposition to, and eventual defeat of, this enormously popular bill found its roots in the bill's economic implications rather than its clinical or humanitarian consequences.