Context-informed incremental learning improves both the performance and resilience of myoelectric control

Despite its rich history of success in controlling powered prostheses and emerging commercial interests in ubiquitous computing, myoelectric control continues to suffer from a lack of robustness. In particular, EMG-based systems often degrade over prolonged use resulting in tedious recalibration sessions, user frustration, and device abandonment. Unsupervised adaptation is one proposed solution that updates a model's parameters over time based on its own predictions during real-time use to maintain robustness without requiring additional user input or dedicated recalibration. However, these strategies can actually accelerate performance deterioration when they begin to classify (and thus adapt) incorrectly, defeating their own purpose. To overcome these limitations, we propose a novel adaptive learning strategy, Context-Informed Incremental Learning (CIIL), that leverages in situ context to better inform the prediction of pseudo-labels. In this work, we evaluate these CIIL strategies in an online target acquisition task for two use cases: (1) when there is a lack of training data and (2) when a drastic and enduring alteration in the input space has occurred. A total of 32 participants were evaluated across the two experiments. The results show that the CIIL strategies significantly outperform the current state-of-the-art unsupervised high-confidence adaptation and outperform models trained with the conventional screen-guided training approach, even after a 45-degree electrode shift (p < 0.05). Consequently, CIIL has substantial implications for the future of myoelectric control, potentially reducing the training burden while bolstering model robustness, and leading to improved real-time control.

Characteristics of the Sexual Networks of Men Who Have Sex With Men in Montréal, Toronto, and Vancouver: Insights from Canada's 2022 Mpox Outbreak

BACKGROUND

The 2022-2023 global mpox outbreak disproportionately affected gay, bisexual, and other men who have sex with men (GBM). We investigated differences in GBM's sexual partner distributions across Canada's 3 largest cities and over time, and how they shaped transmission.

METHODS

The Engage Cohort Study (2017-2023) recruited GBM via respondent-driven sampling in Montréal, Toronto, and Vancouver (n = 2449). We compared reported sexual partner distributions across cities and periods: before COVID-19 (2017-2019), pandemic (2020-2021), and after lifting of restrictions (2021-2023). We used Bayesian regression and poststratification to model partner distributions. We estimated mpox's basic reproduction number (R0) using a risk-stratified compartmental model.

RESULTS

Pre-COVID-19 pandemic distributions were comparable: fitted average partners (past 6 months) were 10.4 (95% credible interval: 9.4-11.5) in Montréal, 13.1 (11.3-15.1) in Toronto, and 10.7 (9.5-12.1) in Vancouver. Sexual activity decreased during the pandemic and increased after lifting of restrictions, but remained below prepandemic levels. Based on reported cases, we estimated R0 of 2.4 to 2.7 and similar cumulative incidences (0.7%-0.9%) across cities.

CONCLUSIONS

Similar sexual partner distributions may explain comparable R0 and cumulative incidence across cities. With potential for further recovery in sexual activity, mpox vaccination and surveillance strategies should be maintained.

Generalizing Upper Limb Force Modeling With Transfer Learning: A Multimodal Approach Using EMG and IMU for New Users and Conditions

In the field of EMG-based force modeling, the ability to generalize models across individuals could play a significant role in its adoption across a range of applications, including assistive devices, robotic and rehabilitation devices. However, current studies have predominately focused on intra-subject modeling, largely neglecting the burden of end-user data acquisition. In this work, we propose the use of transfer learning (TL) to generalize force modeling to a new user by first establishing a baseline model trained using other users' data, and then adapting to the end-user using a small amount of new data (only 10% , 20% , and 40% of the new user data). Using a deep multimodal convolutional neural network, consisting of two CNN models, one with high-density (HD) EMG and one with motion data recorded by an Inertial Measurement Unit (IMU), our proposed TL technique significantly improved force modeling compared to leave-one-subject-out (LOSO) and even intra-subject scenarios. The TL approach increased the average R squared values of the force modeling task by 60.81%, 190.53%, and 199.79% compared to the LOSO case, and by 13.4%, 36.88%, and 45.51% compared to the intra-subject case for isotonic, isokinetic and dynamic conditions, respectively. These results show that it is possible to adapt to a new user with minimal data while improving performance significantly compared to the intra-subject scenario. We also show that TL can be used to generalize on a new experimental condition for a new user.

A two-centre experience of tonsil biopsies in the investigation of patients with tonsillar asymmetry

INTRODUCTION

We aim to evaluate our experience of tonsil biopsies in the investigation of patients presenting with asymmetrical tonsils.

METHODS

A two-centre retrospective analysis of all patients who underwent histology sampling of the palatine tonsils between 1 January 2013 and 31 December 2018 was completed. Data collected included patient demographics, method of obtaining tonsil tissue, histological diagnosis and need for repeat tissue sampling. A follow-up period of 36 months was allowed to establish whether any patients re-presented with missed diagnoses.

RESULTS

In total, 937 patients were included for analysis: 375 (40.0%) had a biopsy, of which 191 (50.9%) were performed in clinic. The mean duration from initial appointment with the ear, nose and throat clinic to tissue sample collection was 17.6 days (range 0-327 days) for all biopsies, reducing to 0.2 days (range 0-17 days) for biopsies performed in clinic. This was significantly shorter than for tonsillectomies (mean 38.9 days, range 0-444 days; p<0.05). Of the patients who underwent tonsil biopsy, six (1.6%) had malignancy that was not unequivocally diagnosed on initial biopsy. In all six patients, prior clinical suspicion was high, and repeat tissue sampling was undertaken on receipt of negative histology results.

CONCLUSIONS

Tonsil biopsy is a viable alternative to tonsillectomy for histology in the assessment of tonsil asymmetry. Tonsil biopsy in the outpatient setting has reduced surgical morbidity, significantly less delay in diagnosis, less inconvenience for patients and lower healthcare costs compared with formal tonsillectomy. Although tonsil biopsies should not be used in isolation, they can be useful in the investigation of patients presenting with tonsillar asymmetry.

Association between Hashimoto's thyroiditis and melanoma: a retrospective matched cohort study

An inflammatory microenvironment has been shown to increase risk for malignant melanoma, suggesting that melanoma may be related to a pro-inflammatory state. Though Hashimoto's thyroiditis is one of the most common autoimmune diseases, there are no investigations of its relationship with melanoma. We aim to determine if Hashimoto's increases risk of developing melanoma. A retrospective, validated cohort of patients with a diagnosis of Hashimoto's between 2005 and 2020 were identified using the Olmsted County database. Patients were age and sex matched to controls without a Hashimoto's diagnosis. The primary outcomes were development of melanoma and time to first melanoma diagnosis. 4805 patients were included in the study, with 1726 (36%) having a diagnosis of Hashimoto's. Hashimoto's patients had no significant difference in risk of melanoma (relative risk 0.96, 95% CI 0.78-1.17) or nonmelanoma skin cancer (relative risk 0.95, 95% CI 0.86-1.06) compared with matched controls. This suggests that the local proinflammatory environment present in Hashimoto's does not contribute significantly to melanoma risk. Larger studies may be needed to further characterize the relationship between these diseases.

Spontaneous shunt independence in paediatric tumour-related hydrocephalus: case series and review of the literature

PURPOSE

Hydrocephalus is commonly associated with paediatric posterior fossa tumours and their resection. This is commonly managed by ventriculoperitoneal shunt insertion, which is associated with a lifelong risk of malfunction, necessitating revisional surgery. Few opportunities ever arise for the patient to be free of the shunt and this risk. We describe three patients shunted for tumour-related hydrocephalus who subsequently developed spontaneous shunt independence. We discuss this in the context of the literature.

METHODS

A single-centre retrospective case series analysis was performed using a departmental database. Case notes were retrieved from a local electronic records database, and images were reviewed using national Picture Archiving and Communication Systems.

RESULTS

Over a 10-year period, 28 patients underwent ventriculoperitoneal shunt insertion for tumour-related hydrocephalus. Of these, 3 patients (10.7%) went on to have their shunts successfully removed. Age at presentation varied from 1 to 16 years. In all cases, the patient required shunt externalization due to shunt or intra-abdominal infection. This was used as an opportunity to challenge the need for ongoing cerebrospinal fluid (CSF) diversion. In one case, this occurred only several months after a shunt blockage with intracranial pressure monitoring that proved her shunt dependence. All three patients tolerated this challenge, their shunt systems were removed without complication, and they remain free of hydrocephalus at last follow-up.

CONCLUSION

These cases reflect our poor understanding of the heterogenous physiology of patients with shunted hydrocephalus and underline the importance of challenging the need for CSF diversion at any appropriate opportunity.

Novel Wearable HD-EMG Sensor With Shift-Robust Gesture Recognition Using Deep Learning

In this work, we present a hardware-software solution to improve the robustness of hand gesture recognition to confounding factors in myoelectric control. The solution includes a novel, full-circumference, flexible, 64-channel high-density electromyography (HD-EMG) sensor called EMaGer. The stretchable, wearable sensor adapts to different forearm sizes while maintaining uniform electrode density around the limb. Leveraging this uniformity, we propose novel array barrel-shifting data augmentation (ABSDA) approach used with a convolutional neural network (CNN), and an anti-aliased CNN (AA-CNN), that provides shift invariance around the limb for improved classification robustness to electrode movement, forearm orientation, and inter-session variability. Signals are sampled from a 4×16 HD-EMG array of electrodes at a frequency of 1 kHz and 16-bit resolution. Using data from 12 non-amputated participants, the approach is tested in response to sensor rotation, forearm rotation, and inter-session scenarios. The proposed ABSDA-CNN method improves inter-session accuracy by 25.67% on average across users for 6 gesture classes compared to conventional CNN classification. A comparison with other devices shows that this benefit is enabled by the unique design of the EMaGer array. The AA-CNN yields improvements of up to 63.05% accuracy over non-augmented methods when tested with electrode displacements ranging from -45 ° to +45 ° around the limb. Overall, this article demonstrates the benefits of co-designing sensor systems, processing methods, and inference algorithms to leverage synergistic and interdependent properties to solve state-of-the-art problems.

CELPI: trial protocol for a randomised controlled trial of a Carer End of Life Planning Intervention in people dying with dementia

Background

Dementia is a leading cause of death in developed nations. Despite an often distressing and symptom laden end of life, there are systematic barriers to accessing palliative care in older people dying of dementia. Evidence exists that 70% of people living with severe dementia attend an emergency department (ED) in their last year of life. The aim of this trial is to test whether a Carer End of Life Planning Intervention (CELPI), co-designed by consumers, clinicians and content specialists, improves access to end of life care for older people with severe dementia, using an ED visit as a catalyst for recognising unmet needs and specialist palliative care referral where indicated.

Methods

A randomised controlled trial (RCT) enrolling at six EDs across three states in Australia will be conducted, enrolling four hundred and forty dyads comprising a person with severe dementia aged ≥ 65 years, and their primary carer.

Participants will be randomly allocated to CELPI or the control group. CELPI incorporates a structured carer needs assessment and referral to specialist palliative care services where indicated by patient symptom burden and needs assessment. The primary outcome measure is death of the person with dementia in the carer-nominated preferred location. Secondary outcomes include carer reported quality of life of the person dying of dementia, hospital bed day occupancy in the last 12 months of life, and carer stress. An economic evaluation from the perspective of a health funder will be conducted.

Discussion

CELPI seeks to support carers and provide optimal end of life care for the person dying of dementia. This trial will provide high level evidence as to the clinical and cost effectiveness of this intervention.

Trial registration

ACTRN12622000611729 registered 22/04/2022.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-03534-1.

284 DO MEDICATIONS GET OPTIMISED DURING AN ACUTE ADMISSION TO HOSPITAL?

Background

Potentially Inappropriate Prescriptions (PIPs) and Potential Prescribing Omissions (PPOs) are common in hospitalised older adults and associated with poor outcomes. The aim of this study was to assess whether PIPs and PPOs are reduced during an acute hospital admission.

Methods

All inpatients on 5 gerontological wards (1 acute, 1 subacute, 2 rehabilitation, 1 long-stay) on October 31st 2021 were eligible for inclusion. Medical records were retrospectively reviewed. Medication appropriateness was assessed by two assessors at admission and discharge using STOPP/START version 2. Records were consecutively reviewed according to discharge date. Ethical approval was received from the local research and innovation office (ref6275)

Results

Of 144 eligible patients, 41 were included; mean age 82.1 (SD6.8) years; 48.8% female, 95.1% under the care of geriatricians. The median length of stay was 24 (IQR10-67.5) days. Mean number of conditions was 5.6 (SD2.9) with dementia present in 22.5%. The mean number of medications increased during admission from 7.2 (SD3.2) to 9 (SD3.1); p=0.006

The number of patients prescribed at least 1 STOPP-PIP reduced by 20.6%; 82.9% (admission) vs 65.9% (discharge), p&lt;0.001. The most common PIPs at were (i) drugs without a clear indication, 34.1% (admission) vs 14.6% (discharge), (ii) high dose proton pump inhibitors, 34.1% (admission) vs 34.1% (discharge) and (iii) Z-drugs in fallers; 17.1% (admission) vs 12.2% (discharge). Of 41 patients, 35 could have START criteria applied. START PPOs were reduced by 53%; 47.2% (admission) vs 22.2% (discharge), p=0.001. The largest improvement was seen in bone absorptive therapy (11.4% (admission) vs 2.9% (discharge) and vitamin d in those experiencing falls/osteopenia; 5.57% (admission) vs 2.9% (discharge). Of the 134 STOPP/START criteria listed, 36 (19.4%) were identified in this cohort.

Conclusion

Although the average number of medications increased, PIPs reduced significantly. Only 19.4% of STOPP/START criteria were identified, suggesting that focusing on a number of key PIPs going forward could improve prescribing practices.

National audit of non-melanoma skin cancer excisions performed by plastic surgery in the UK

A national, multi-centre audit of non-melanoma skin cancer excisions by plastic surgery.

Effects of Exercise Training on Neurotrophic Factors and Subsequent Neuroprotection in Persons with Multiple Sclerosis-A Systematic Review and Meta-Analysis

Background: Evidence indicates that exercise holds the potential to counteract neurodegeneration experienced by persons with multiple sclerosis (pwMS), which is in part believed to be mediated through increases in neurotrophic factors. There is a need to summarize the existing evidence on exercise-induced effects on neurotrophic factors alongside neuroprotection in pwMS. Aim: To (1) systematically review the evidence on acute (one session) and/or chronic (several sessions) exercise-induced changes in neurotrophic factors in pwMS and (2) investigate the potential translational link between exercise-induced changes in neurotrophic factors and neuroprotection. Methods: Five databases (Medline, Scopus, Web of Science, Embase, Sport Discus) were searched for randomized controlled trials (RCT) examining the effects of exercise (all modalities included) on neurotrophic factors as well as measures of neuroprotection if reported. The quality of the study designs and the exercise interventions were assessed by use of the validated tool TESTEX. Results: From N = 337 identified studies, N = 14 RCTs were included. While only N = 2 of the identified studies reported on the acute changes in neurotrophic factors, all N = 14 RCTs reported on the chronic effects, with N = 9 studies revealing between-group differences in favor of exercise. This was most prominent for brain-derived neurotrophic factor (BDNF), with between-group differences in favor of exercise being observed in N = 6 out of N = 12 studies. Meta-analyses were applicable for three out of 10 different identified neurotrophic factors and revealed that exercise can improve the chronic levels of BDNF (delta changes; N = 9, ES = 0.78 (0.27; 1.28), p = 0.003, heterogeneity between studies) and potentially also ciliary neurotrophic factor (CNTF) (N = 3, ES = 0.24 (−0.07; 0.54), p = 0.13, no heterogeneity between studies) but not nerve growth factor (NGF) (N = 4, ES = 0.28 (−0.55; 1.11), p = 0.51, heterogeneity between studies). Indicators of neuroprotection (e.g., with direct measures of brain structure assessed by MRI) were assessed in N = 3 of the identified studies only, with N = 2 partly supporting and thus indicating a potential translational link between increases in neurotrophic factors and neuroprotection. Conclusion: The present study reveals that exercise can elicit improvements in chronic levels of BDNF in pwMS, whereas the effects of exercise on chronic levels of other neurotrophic factors and on acute levels of neurotrophic factors in general, along with a potential translational link (i.e., with exercise-induced improvements in neurotropic factors being associated with or even mediating neuroprotection), are sparse and inconclusive. There is a need for more high-quality studies that assess neurotrophic factors (applying comparable methods of blood handling and analysis) concomitantly with neuroprotective outcome measures. Review Registration: PROSPERO (ID: CRD42020177353).

598 Burns Management at A UK Major Trauma Centre During The COVID-19 Lockdown

Aim

The COVID-19 pandemic forced huge changes in healthcare delivery in the UK within a matter of weeks. We report our experience of managing burns presenting to a UK Major Trauma Centre during the COVID-19 lockdown period.

Method

Retrospective patient data was collected on aetiology, severity and management of burns during the first six weeks of the government-enforced lockdown. Data was compared with patients presenting with burns during the same period in 2019 (control) and statistical analysis was performed.

Results

Fifteen patients were treated during the COVID-19 lockdown and fourteen in the control group. Adults treated during the COVID-19 lockdown had a greater total body surface area (TBSA) (9% vs. 2.9%, p 0.035) and were more likely to suffer full thickness burns (40% vs. 0%). In the COVID-19 group all patients that did not require resuscitation, seven of whom met criteria for referral to burns services, were managed locally by the plastic surgery department with good outcomes.

Conclusions

Despite the increase in severity of adult burns seen during the COVID-19 lockdown period, local plastic surgery units have been able to adapt their practice and successfully manage more complex burns. This adaptability will be key as we move through the pandemic.

Home range and movements of Amazon river dolphins Inia geoffrensis in the Amazon and Orinoco river basins

Studying the variables that describe the spatial ecology of threatened species allows us to identify and prioritize areas that are critical for species conservation. To estimate the home range and core area of the Endangered (EN) Amazon river dolphin Inia geoffrensis, 23 individuals (6&female;, 17&male;) were tagged during the rising water period in the Amazon and Orinoco river basins between 2017 and 2018. The satellite tracking period ranged from 24 to 336 d (mean ± SE = 107 ± 15.7 d), and river dolphin movements ranged from 7.5 to 298 km (58 ± 13.4 km). Kernel density estimates were used to determine minimum home ranges at 95% (K95 = 6.2 to 233.9 km2; mean = 59 ± 13.5 km2) and core areas at 50% (K50 = 0.6 to 54.9 km2; mean = 9 ± 2.6 km2). Protected areas accounted for 45% of the K50 estimated core area. We observed dolphin individuals crossing country borders between Colombia and Peru in the Amazon basin, and between Colombia and Venezuela in the Orinoco basin. Satellite tracking allowed us to determine the different uses of riverine habitat types: main rivers (channels and bays, 52% of recorded locations), confluences (32%), lagoons (9.6%), and tributaries (6.2%). Satellite monitoring allowed us to better understand the ecological preferences of the species and demonstrated the importance of maintaining aquatic landscape heterogeneity and spatial connectivity for effective river dolphin conservation.

Resistance exercise training at different loads in frail and healthy older adults: A randomised feasibility trial

Objectives

This trial aimed to determine the feasibility of recruitment, retention, adherence, and safety of a resistance training (RT) intervention to skeletal muscle failure in both frail and non-frail older adults.

Design

An 8-week randomised feasibility trial.

Setting and participants

Older adults, with and without frailty, recruited from both clinics and community.

Methods

Recruitment was based on the number of participants enrolled from those provided with a Patient Information Sheet (PIS). Retention was based on the number of participants who completed the trial. Adherence was based on the number of RT sessions attended out of 16. Outcomes included frailty (Fried criteria), muscle strength (maximal voluntary contraction), functional abilities (Short Physical Performance battery), quality of life (EQ-5D-5L), activities of daily living (LIADL) and safety (diary).

Results

Recruitment target (n = 60) was achieved within 15 months, 58 were randomised to high (n = 30) or low repetition-load (n = 28) groups. Mean age of participants was 72 years (range 65–93). Adherence and retention rate for the RT intervention was ≥70%. There was one serious adverse experience due to the RT intervention. There were no differences (P > 0.05) in effects of RT on outcome variables between low and high repetition-load groups.

Conclusions and implications

Recruitment of frail people was challenging. Older adults performing supervised RT to skeletal muscle failure was feasible and safe, with appropriate caution, and the repetition-load did not appear to influence its efficacy. Future research into the effectiveness of this simplified model of RT is warranted.

•

Resistance exercise is the most effective way to increase muscle mass.

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This is particularly important in older adults.

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Recruitment of older adults, particularly with frailty, is challenging.

•

We found recruitment of older adults feasible, but less so for those with frailty.

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The load for exercise did not appear to influence efficacy of exercise.

Zonisamide safety in pregnancy: Data from the UK and Ireland epilepsy and pregnancy register

BACKGROUND

Animal data suggest teratogenic effects with zonisamide use and risk of pregnancy losses. Human data following zonisamide exposure are presently limited, but suggest low risk of malformation with elevated risk of low birth weight.

OBJECTIVE

To calculate the major congenital malformation (MCM) rate of zonisamide in human pregnancy and assess for a signal of any specific malformation pattern and associations with birth weight.

METHODS AND MATERIALS

Data were obtained from the UK and Ireland Epilepsy and Pregnancy register (UKIEPR) which is an observational, registration, and follow up study from December 1996 to July 2020. Eligibility criteria were use of zonisamide and to have been referred to the UKIEPR before the outcome of the pregnancy was known. Primary outcome was evidence of MCM.

RESULTS

From December 1996 through July 2020 there were 112 cases of first trimester exposure to zonisamide, including 26 monotherapy cases. There were 3 MCM for monotherapy cases (MCM rate 13.0% (95% confidence interval 4.5-32.1)), and 5 MCM for polytherapy cases (MCM rate 6.9% (95% confidence interval 3.0-15.2)). While the median birth weight was on 71st and 44th centile for monotherapy and polytherapy cases respectively, there was a high rate of infants born small for gestational age (21% for both).

CONCLUSION

These data raise concerns about a signal for potential teratogenicity with zonisamide in human pregnancy. Given the low numbers reported, further data will be required to adequately counsel women who use zonisamide in pregnancy.

Deep Cross-User Models Reduce the Training Burden in Myoelectric Control

The effort, focus, and time to collect data and train EMG pattern recognition systems is one of the largest barriers to their widespread adoption in commercial applications. In addition to multiple repetitions of motions, including exemplars of confounding factors during the training protocol has been shown to be critical for robust machine learning models. This added training burden is prohibitive for most regular use cases, so cross-user models have been proposed that could leverage inter-repetition variability supplied by other users. Existing cross-user models have not yet achieved performance levels sufficient for commercialization and require users to closely adhere to a training protocol that is impractical without expert guidance. In this work, we extend a previously reported adaptive domain adversarial neural network (ADANN) to a cross-subject framework that requires very little training data from the end-user. We compare its performance to single-repetition within-user training and the previous state-of-the-art cross-subject technique, canonical correlation analysis (CCA). ADANN significantly outperformed CCA for both intact-limb (86.8–96.2%) and amputee (64.1–84.2%) populations. Moreover, the ADANN adaptation computation time was substantially lower than the time otherwise devoted to conducting a full within-subject training protocol. This study shows that cross-user models, enabled by deep-learned adaptations, may be a viable option for improved generalized pattern recognition-based myoelectric control.

Marine mammal conservation: over the horizon

Marine mammals can play important ecological roles in aquatic ecosystems, and their presence can be key to community structure and function. Consequently, marine mammals are often considered indicators of ecosystem health and flagship species. Yet, historical population declines caused by exploitation, and additional current threats, such as climate change, fisheries bycatch, pollution and maritime development, continue to impact many marine mammal species, and at least 25% are classified as threatened (Critically Endangered, Endangered or Vulnerable) on the IUCN Red List. Conversely, some species have experienced population increases/recoveries in recent decades, reflecting management interventions, and are heralded as conservation successes. To continue these successes and reverse the downward trajectories of at-risk species, it is necessary to evaluate the threats faced by marine mammals and the conservation mechanisms available to address them. Additionally, there is a need to identify evidence-based priorities of both research and conservation needs across a range of settings and taxa. To that effect we: (1) outline the key threats to marine mammals and their impacts, identify the associated knowledge gaps and recommend actions needed; (2) discuss the merits and downfalls of established and emerging conservation mechanisms; (3) outline the application of research and monitoring techniques; and (4) highlight particular taxa/populations that are in urgent need of focus.

36 Feasibility of Resistance Exercise to Failure at Different Loads in Frail and Healthy Older Adults?

Introduction

Resistance training (RT) is the most effective way to increase muscle mass and function in older adults both with/without sarcopenia/frailty. In younger adults, when RT is performed to muscle failure the load lifted does not mediate the magnitude of response, but there are no studies in older adults. We aimed to determine the feasibility of recruitment to a RT intervention working to muscle failure at different loads in frail and healthy older adults.

Methods

We performed an 8-week randomised feasibility trial of lower limb RT to volitional muscular failure, at high and low load. Participants were recruited via hospital outpatient clinics and newspaper advertisements. Outcomes included: frailty assessment (Fried criteria); muscle strength (maximum voluntary contraction/one-repetition maximum); functional abilities (Short Physical Performance Battery); safety/adverse events were recorded via a log, and patient experiences from focus groups.

Results

110 people were assessed for eligibility, and 58 randomised (frail n = 6, prefrail n = 20, robust n = 32) to either high (n = 30) or low load (n = 28) groups. Mean age of participants was 72 years (range 65–93), 36 were female, 22 male. Session attendance was 95% (high load) and 90.4% (low load). Most participants were recruited via advertisements. All participants reported feeling safe and reassured in the RT sessions. Two participants had a serious adverse event, one related to RT (hypotension) and several had adverse events (three intervention-related). Pain was reported at both loads (high n = 9, low n = 8) yet all completed. There were no differences (P &gt; 0.05) in effects of RT outcome variables between low and high load groups.

Conclusion

In this feasibility trial the recruitment of frail patients via clinics was limited. Performing supervised RT to muscle failure in older adults was safe/acceptable and the load at which RT was performed did not influence its efficacy. Future research into the effectiveness of such RT is warranted.

The COVID-19 Pandemic: The effect on open lower limb fractures in a London major trauma centre - a plastic surgery perspective

BACKGROUND

COVID-19 has created huge pressures on healthcare systems. The ongoing provision of major trauma services during this time has proved challenging. We report our experience of managing open lower limb fractures (oLLFs) during the pandemic in a London major trauma centre (MTC).

METHODS

This was a prospective study of all open lower limb fractures presenting to our unit over the initial 48 days of UK government lockdown - 24th March till 10th May 2020. Results were compared to the same time period in 2019 retrospectively. Epidemiological data, mechanism, Gustilo-Anderson (G-A) severity grading, time to initial debridement and definitive coverage were analysed.

RESULTS

There was a 64% reduction in emergency department (ED) attendances (25,264 vs 9042). There was an 18% reduction in oLLFs (22 vs 18). Approximately three-quarters of injuries were in males across both cohorts (77% vs 78%) and tended to occur in younger patients (median age, 37 vs 35). Road-traffic-accidents (RTAs) were the most common injury mechanism in both 2019 and lockdown, but a rise in jumpers from height was seen in the latter. A similar pattern of G-A severities were seen, however only 3 injuries during lockdown required major soft tissue reconstruction. There was no significant difference in times taken for initial debridement (p = 0.72786) or definitive wound coverage (p = 0.16152). A greater proportion of independent operating was seen during lockdown between orthopaedics and plastic surgery.

CONCLUSIONS

Despite government lockdown measures, oLLFs still placed significant burden on our MTC. Notwithstanding significant staffing alterations and theatre pressures, we have been able to ensure these lower limb emergencies remain a surgical priority and have managed to utilise resources appropriately.

The effect of exercise on quality of life and activities of daily life in frail older adults: A systematic review of randomised control trials

While the positive effects of exercise on frailty are well documented, the effect of exercise on quality of life (QoL) and activities of daily living (ADL) in frail older adults remains less certain. Therefore, this paper aimed to systematically review the literature investigating the effect of exercise on QoL and ADL in this group. Embase, MEDLINE, CENTRAL, PEDro and Web of Science Core Collections were searched systematically using relevant MeSH terms. The inclusion criteria were: controlled trial design, published in English, population included frail older adults, frailty measured quantitatively, interventions that included exercise, and QoL or ADL measurements (PROSPERO: CRD42018106173). After screening, 15 studies were eligible for inclusion in the qualitative synthesis (total n: 2467; mean age range: 70-85 years). There was a positive effect on QoL or ADL measures in 10 out of the 15 studies. QoL and ADLs only improved in studies that also reported improved physical outcomes. These results reflect the multi-factoral nature of frailty and how physical capability and QoL are interlinked. Heterogeneity precluded formal meta-analysis. Future trials in frail older adults should focus on interventions that include exercise, measure physical outcomes and use consistent study design to enable meta-analysis to be conducted.

Hand tendon injuries

This article provides a comprehensive overview of hand tendon injuries. It has been tailored towards healthcare professionals who will be the first to assess these injuries and instigate appropriate management. It discusses the essential hand anatomy to be aware of, how to assess tendon injuries, their initial management and also the definitive surgical interventions used, if required. Rehabilitation techniques are also discussed, as this is also key to good functional outcomes. Missed injuries, or delay in their diagnosis and referral to specialist hand surgeons, can cause a large amount of morbidity for patients and therefore it is important that they are picked up in a timely manner.

Hand infections

The hand is an extremely versatile organ adapted for fine tasks with various clinicoanatomical compartments. This article reviews the types of common hand infections that present to the emergency department and/or hand surgeon, with relevant investigations and strategies for diagnosis and treatment, with the emphasis on distinguishing between superficial and more serious infections.

Feasibility of Data-driven EMG Signal Generation using a Deep Generative Model

Despite recent advancements in the field of pattern recognition-based myoelectric control, the collection of a high quality training set remains a challenge limiting its adoption. This paper proposes a framework for a possible solution by augmenting short training protocols with subject-specific synthetic electromyography (EMG) data generated using a deep generative network, known as SinGAN. The aim of this work is to produce high quality synthetic data that could improve classification accuracy when combined with a limited training protocol. SinGAN was used to generate 1000 synthetic windows of EMG data from a single window of six different motions, and results were evaluated qualitatively, quantitatively, and in a classification task. Qualitative assessment of synthetic data was conducted via visual inspection of principal component analysis projections of real and synthetic feature space. Quantitative assessment of synthetic data revealed 11 of 32 synthetic features had similar location and scale to real features (using univariate two-sample Lepage tests); whereas multivariate distributions were found to be statistically different (p <0.05). Finally, the addition of these synthetic data to a brief training set of real data significantly improved classification accuracy in a cross-validation testing scheme by 5.4% (p <0.001).

Insight into the effects of confined hydrocarbon species on the lifetime of methanol conversion catalysts

The methanol-to-hydrocarbons reaction refers collectively to a series of important industrial catalytic processes to produce either olefins or gasoline. Mechanistically, methanol conversion proceeds through a 'pool' of hydrocarbon species. For the methanol-to-olefins process, these species can be delineated broadly into 'desired' lighter olefins and 'undesired' heavier fractions that cause deactivation in a matter of hours. The crux in further catalyst optimization is the ability to follow the formation of carbonaceous species during operation. Here, we report the combined results of an operando Kerr-gated Raman spectroscopic study with state-of-the-art operando molecular simulations, which allowed us to follow the formation of hydrocarbon species at various stages of methanol conversion. Polyenes are identified as crucial intermediates towards formation of polycyclic aromatic hydrocarbons, with their fate determined largely by the zeolite topology. Notably, we provide the missing link between active and deactivating species, which allows us to propose potential design rules for future-generation catalysts.

Context-dependent plasticity of adult-born neurons regulated by cortical feedback

In a complex and dynamic environment, the brain flexibly adjusts its circuits to preferentially process behaviorally relevant information. Here, we investigated how the olfactory bulb copes with this demand by examining the plasticity of adult-born granule cells (abGCs). We found that learning of olfactory discrimination elevates odor responses of young abGCs and increases their apical dendritic spines. This plasticity did not occur in abGCs during passive odor experience nor in resident granule cells (rGCs) during learning. Furthermore, we found that feedback projections from the piriform cortex show elevated activity during learning, and activating piriform feedback elicited stronger excitatory postsynaptic currents in abGCs than rGCs. Inactivation of piriform feedback blocked abGC plasticity during learning, and activation of piriform feedback during passive experience induced learning-like plasticity of abGCs. Our work describes a neural circuit mechanism that uses adult neurogenesis to update a sensory circuit to flexibly adapt to new behavioral demands.

Current Trends and Confounding Factors in Myoelectric Control: Limb Position and Contraction Intensity

This manuscript presents a hybrid study of a comprehensive review and a systematic(research) analysis. Myoelectric control is the cornerstone ofmany assistive technologies used in clinicalpractice, such as prosthetics and orthoses, and human-computer interaction, such as virtual reality control.Although the classification accuracy of such devices exceeds 90% in a controlled laboratory setting,myoelectric devices still face challenges in robustness to variability of daily living conditions.The intrinsic physiological mechanisms limiting practical implementations of myoelectric deviceswere explored: the limb position effect and the contraction intensity effect. The degradationof electromyography (EMG) pattern recognition in the presence of these factors was demonstratedon six datasets, where classification performance was 13% and 20% lower than the controlledsetting for the limb position and contraction intensity effect, respectively. The experimental designsof limb position and contraction intensity literature were surveyed. Current state-of-the-art trainingstrategies and robust algorithms for both effects were compiled and presented. Recommendationsfor future limb position effect studies include: the collection protocol providing exemplars of at least 6positions (four limb positions and three forearm orientations), three-dimensional space experimentaldesigns, transfer learning approaches, and multi-modal sensor configurations. Recommendationsfor future contraction intensity effect studies include: the collection of dynamic contractions, nonlinearcomplexity features, and proportional control.

Interpreting Deep Learning Features for Myoelectric Control: A Comparison With Handcrafted Features

Existing research on myoelectric control systems primarily focuses on extracting discriminative characteristics of the electromyographic (EMG) signal by designing handcrafted features. Recently, however, deep learning techniques have been applied to the challenging task of EMG-based gesture recognition. The adoption of these techniques slowly shifts the focus from feature engineering to feature learning. Nevertheless, the black-box nature of deep learning makes it hard to understand the type of information learned by the network and how it relates to handcrafted features. Additionally, due to the high variability in EMG recordings between participants, deep features tend to generalize poorly across subjects using standard training methods. Consequently, this work introduces a new multi-domain learning algorithm, named ADANN (Adaptive Domain Adversarial Neural Network), which significantly enhances (p = 0.00004) inter-subject classification accuracy by an average of 19.40% compared to standard training. Using ADANN-generated features, this work provides the first topological data analysis of EMG-based gesture recognition for the characterization of the information encoded within a deep network, using handcrafted features as landmarks. This analysis reveals that handcrafted features and the learned features (in the earlier layers) both try to discriminate between all gestures, but do not encode the same information to do so. In the later layers, the learned features are inclined to instead adopt a one-vs.-all strategy for a given class. Furthermore, by using convolutional network visualization techniques, it is revealed that learned features actually tend to ignore the most activated channel during contraction, which is in stark contrast with the prevalence of handcrafted features designed to capture amplitude information. Overall, this work paves the way for hybrid feature sets by providing a clear guideline of complementary information encoded within learned and handcrafted features.

Prior endoscopic third ventriculostomy does not increase ventriculoperitoneal shunt failure rate

PURPOSE

To determine whether prior endoscopic third ventriculostomy (ETV) influences the failure rate of subsequently placed ventriculoperitoneal (VP) shunts.

METHODS

Our institution's operative database and patient records were reviewed retrospectively to identify all paediatric patients who had undergone a first VP shunt or ETV at our institution between January 2012 and December 2015. Data was analysed using the Microsoft Excel, GraphPad Prism v7 and SPSS statistics. The literature on this topic to date was also reviewed.

RESULTS

Eighty-six children were included in the study: 61 patients had a primary VP shunt inserted during the study period and 25 had a VP shunt inserted following failed ETV. There was no significant difference in the underlying aetiology or age of the patients in each group. In the primary VP shunt group, 47.5% (29 patients) required shunt removal at an average of 274 days post-insertion (range 7 days to 3.4 years). The 1-year revision rate was 34.4%. In the shunt post-ETV group, 48% (12 patients) required shunt removal at an average of 207 days post-insertion (range 2 days to 2.7 years). The 1-year revision rate was 36%. The most common reason for revision in both groups was blockage.

CONCLUSIONS

We found no significant difference in failure rate or pattern between primarily inserted VP shunts and those inserted following an endoscopic third ventriculostomy. On the basis of this study and the small number of previously reported studies, we would advocate a trial of ETV where feasible to allow a chance at shunt independence.

Feature Extraction and Selection for Pain Recognition Using Peripheral Physiological Signals

In pattern recognition, the selection of appropriate features is paramount to both the performance and the robustness of the system. Over-reliance on machine learning-based feature selection methods can, therefore, be problematic; especially when conducted using small snapshots of data. The results of these methods, if adopted without proper interpretation, can lead to sub-optimal system design or worse, the abandonment of otherwise viable and important features. In this work, a deep exploration of pain-based emotion classification was conducted to better understand differences in the results of the related literature. In total, 155 different time domain and frequency domain features were explored, derived from electromyogram (EMG), skin conductance levels (SCL), and electrocardiogram (ECG) readings taken from the 85 subjects in response to heat-induced pain. To address the inconsistency in the optimal feature sets found in related works, an exhaustive and interpretable feature selection protocol was followed to obtain a generalizable feature set. Associations between features were then visualized using a topologically-informed chart, called Mapper, of this physiological feature space, including synthesis and comparison of results from previous literature. This topological feature chart was able to identify key sources of information that led to the formation of five main functional feature groups: signal amplitude and power, frequency information, nonlinear complexity, unique, and connecting. These functional groupings were used to extract further insight into observable autonomic responses to pain through a complementary statistical interaction analysis. From this chart, it was observed that EMG and SCL derived features could functionally replace those obtained from ECG. These insights motivate future work on novel sensing modalities, feature design, deep learning approaches, and dimensionality reduction techniques.

Graphene Oxide as a Multifunctional Platform for Intracellular Delivery, Imaging, and Cancer Sensing

Graphene oxide (GO), the most common derivative of graphene, is an exceptional nanomaterial that possesses multiple physical properties critical for biomedical applications. GO exhibits pH-dependent fluorescence emission in the visible/near-infrared, providing a possibility of molecular imaging and pH-sensing. It is also water soluble and has a substantial platform for functionalization, allowing for the delivery of multiple therapeutics. GO physical properties are modified to enhance cellular internalization, producing fluorescent nanoflakes with low (<15%) cytotoxicity at the imaging concentrations of 15 μg/mL. As a result, at lower flake sizes GO rapidly internalizes into HeLa cells with the following 70% fluorescence based clearance at 24 h, assessed by its characteristic emission in red/near-IR. pH-dependence of GO emission is utilized to provide the sensing of acidic extracellular environments of cancer cells. The results demonstrate diminishing green/red (550/630 nm) fluorescence intensity ratios for HeLa and MCF-7 cancer cells in comparison to HEK-293 healthy cells suggesting a potential use of GO as a non-invasive optical sensor for cancer microenvironments. The results of this work demonstrate the potential of GO as a novel multifunctional platform for therapeutic delivery, biological imaging and cancer sensing.

Validation of smartphone step count algorithm used in STARFISH smartphone application

BACKGROUND

Smartphone sensors are underutilised in rehabilitation.

OBJECTIVE

To validate the step count algorithm used in the STARFISH smartphone application.

METHODS

Twenty-two healthy adults (8 male, 14 female) walked on a treadmill for 5 minutes at 0.44, 0.67, 0.90 and 1.33 m⋅s-1. Each wore an activPALTM and four Samsung Galaxy S3TM smartphones, with the STARFISH application running, in: 1) a belt carrycase, 2) a trouser or skirt pocket), 3a) a handbag on shoulder for females or 3b) shirt pocket for males and 4) an upper arm strap. Step counts of the STARFISH application and the activPALTM were compared at corresponding speeds and Bland-Altman statistics used to assess level of agreement (LOA).

RESULTS

The LOA between the STARFISH application and activPALTM varied across the four speeds and positions, but improved as speed increased. The LOA ranged from 105-177% at 0.44 m⋅s-1; 50-98% at 0.67 m⋅s-1; 19-67% at 0.9 m⋅s-1 and 8-53% at 1.33 m⋅s-1. The best LOAs were at 1.33 m⋅s-1 in the shirt pocket (8%) and upper arm strap (12%) positions.

CONCLUSIONS

Step counts measured by the STARFISH smartphone application are valid in most body positions especially at walking speeds of 0.9 m⋅s-1 and above.

High intensity interval training for people with multiple sclerosis: A systematic review

BACKGROUND

Aerobic high intensity interval training (HIIT) is safe in the general population and more efficient in improving fitness than continuous moderate intensity training. The body of literature examining HIIT in multiple sclerosis (MS) is expanding but to date a systematic review has not been conducted. The aim of this review was to investigate the efficacy and safety of HIIT in people with MS.

METHODS

A systematic search was carried out in September 2017 in EMBASE, MEDline, PEDro, CENTRAL and Web of Science Core collections using appropriate keywords and MeSH descriptors. Reference lists of relevant articles were also searched. Articles were eligible for inclusion if they were published in English, used HIIT, and included participants with MS. Quality was assessed using the PEDro scale. The following data were extracted using a standardised form: study design and characteristics, outcome measures, significant results, drop-outs, and adverse events.

RESULTS

Seven studies (described by 11 articles) were identified: four randomised controlled trials, one randomised cross-over trial and two cohort studies. PEDro scores ranged from 3 to 8. Included participants (n = 249) were predominantly mildly disabled; one study included only people with progressive MS. Six studies used cycle ergometry and one used arm ergometry to deliver HIIT. One study reported six adverse events, four which could be attributed to the intervention. The other six reported that there were no adverse events. Six studies reported improvements in at least one outcome measure, however there were 60 different outcome measures in the seven studies. The most commonly measured domain was fitness, which improved in five of the six studies measuring aspects of fitness. The only trial not to report positive results included people with progressive and a more severe level of disability (Extended Disability Status Scale 6.0-8.0).

CONCLUSION

HIIT appears to be safe and effective in increasing fitness in people with MS and low levels of disability. Further research is required to explore the effectiveness of HIIT in people with progressive MS and in those with higher levels of disability.

Telephone-based weight loss support for patients with knee osteoarthritis: a pragmatic randomised controlled trial

OBJECTIVE

To determine the effectiveness of telephone-based weight loss support in reducing the intensity of knee pain in patients with knee osteoarthritis, who are overweight or obese, compared to usual care.

DESIGN

We conducted a parallel randomised controlled trial (RCT), embedded within a cohort multiple RCT of patients on a waiting list for outpatient orthopaedic consultation at a tertiary referral hospital in NSW, Australia. Patients with knee osteoarthritis, classified as overweight or obese [body mass index (BMI) between ≥27 kg/m² and <40 kg/m²] were randomly allocated to receive referral to an existing non-disease specific government funded 6-month telephone-based weight management and healthy lifestyle service or usual care. The primary outcome was knee pain intensity measured using an 11-point numerical rating scale (NRS) over 6-month follow-up. A number of secondary outcomes, including self-reported weight were measured. Data analysis was by intention-to-treat according to a pre-published analysis plan.

RESULTS

Between May 19 and June 30 2015, 120 patients were randomly assigned to the intervention (59 analysed, one post-randomisation exclusion) or usual care (60 analysed). We found no statistically significant between group differences in pain intensity [area under the curve (AUC), mean difference 5.4, 95%CI: -13.7 to 24.5, P = 0.58] or weight change at 6 months (self-reported; mean difference -0.4, 95%CI: -2.6 to 1.8, P = 0.74).

CONCLUSIONS

Among patients with knee osteoarthritis who are overweight, telephone-based weight loss support, provided using an existing 6-month weight management and healthy lifestyle service did not reduce knee pain intensity or weight, compared with usual care.

TRIAL REGISTRATION NUMBER

ACTRN12615000490572.

Abstract PD8-06: Attitudes towards use of archived biospecimens among patients with cancer

Background: Oncology research increasingly involves biospecimen collection and data-sharing. Ethical questions have emerged when researchers seek to use archived biospecimens for purposes that were not well defined in the original informed consent document (ICD). We sought to inform ongoing debates by assessing patient views on these issues.

Methods: We administered a cross-sectional self administered anonymous paper survey among patients at the Massachusetts General Hospital Cancer Center. Survey questions addressed attitudes towards cancer research and willingness to donate biospecimens, expectations regarding use of biospecimens and protections of research participants, and preferences regarding specific ethical dilemmas regarding use of archived biospecimens. Results are descriptive with comparisons among participants on the sociodemographic and clinical characteristics using chi-square and Fisher's exact tests.

Results: 187 patients offered participation agreed and returned the survey (Response rate 66%). Mean age was 59 (range 2 to 91), 81% were women, 86% were white, and 81% were college educated. Among all participants, 67% had breast cancer and 33% metastatic disease. 34% had participated in a clinical trial, 27% had donated tissue for research and 93% indicated willingness to donate tissue for research. The vast majority of participants (94%) expected both that donated tissue would be used to help as many patients as possible and (92%) that privacy of a donors health information would be carefully protected. 33% expected that donated tissue would only be used for research they specifically approved and 44% that data would not be shared with other researchers. We presented 3 hypothetical scenarios in which researchers sought to use stored biospecimens from a breast cancer clinical trial for future research that was not described in the original iICD. For scenario 1, in which the ICD stated tissue would only be used for breast cancer research, 75% supported use of tissue to study other cancers as well. For scenario 2, in which the ICD specified somatic genetic research only, 89% supported use of tissue for germline research if deemed important by investigators. For scenario 3, in which the ICD stated that data would not be shared beyond the investigators, 72% supported data sharing within a national data repository. Only 28% of participants endorsed concerns that a patient could be identified from their genetic information and 12% were concerned with potential harms from donation to biobanks. However, 38% felt that they owned their tissue and should control how it is used. We did not detect significant differences in responses on the basis of sociodemographic characteristics, cancer type, disease stage, or research experience.

Conclusion: Patients with cancer are highly supportive of tissue donation for research and expect that donated tissue will be used to to maximize scientific results. They also expect that interests of research participants will be protected. When there is uncertainly regarding the use of archived biospecimens based on historical ICD and inability to recontact research participants, the interest of participants in seeing productive use of their tissue for science should be considered.

Citation Format: Peppercorn J, Campbell E, Rabin J, Quain K, Hlubocky F, Colyar D, Sequist L, Bardia A, Horick N, Isakoff S, Mathews D. Attitudes towards use of archived biospecimens among patients with cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr PD8-06.

Access to and Use of Clinical Services and Disease-Modifying Therapies by People with Progressive Multiple Sclerosis in the United Kingdom

Background

According to current UK guidelines, everyone with progressive multiple sclerosis (MS) should have access to an MS specialist, but levels of access and use of clinical services is unknown. We sought to investigate access to MS specialists and use of clinical services and disease-modifying therapies (DMTs) by people with progressive MS in the United Kingdom.

Methods

A UK-wide online survey was conducted via the UK MS Register. The inclusion criteria were age 18 years or older, primary or secondary progressive MS, and a member of the UK MS Register. Participants were asked about access to MS specialists, recent clinical service use, receipt of regular review, and current and previous DMT use. Participant demographic data, quality of life, and disease impact measures were from the UK MS Register.

Results

In total, 1298 individuals responded: 7% were currently taking a DMT, 23% had previously taken a DMT, and 95% reported access to an MS specialist. The most used practitioners were MS doctors/nurses (50%), general practitioners (45%), and physiotherapists (40%). Seventy-four percent of participants received a regular review, although 37% received theirs less often than annually. Current DMT use was associated with better quality of life, but past DMT use was associated with poorer quality of life and higher impact of disease.

Conclusions

Access to and use of MS specialists was high. However, a gap in service provision was highlighted in both receipt and frequency of regular reviews.

Psychological Well-Being of Participants in Wheelchair Sports: Comparison of Individuals with Congenital and Acquired Disabilities

Differences in psychological well-being between participants in wheelchair sport with congenital ( n = 50) and acquired ( n = 43) disabilities were examined. Psychological well-being was assessed by scores on mood, trait anxiety, self-esteem, and mastery. Analysis showed that the group with acquired disabilities had a more positive general mood, higher self-esteem and mastery, and lower trait anxiety than the group with congenital disabilities. This suggests that sports participants in wheelchairs who acquired their disabilities later in life have more positive scores on psychological well-being than those with congenital disabilities.

The risk of oesophageal adenocarcinoma in a prospectively recruited Barrett's oesophagus cohort

BACKGROUND

Varying rates of oesophageal adenocarcinoma (OAC) complicating Barrett's oesophagus (BO) have been reported. Recent studies and meta-analyses suggest a lower incidence, questioning the value of endoscopic surveillance.

AIM

We aimed to retrospectively examine the rate of OAC, risk factors and causes of death in a prospectively recruited BO cohort.

METHODS

Data from patients with BO from a cohort from 1982-2007 were studied. Patients were subdivided into surveyed, failed to attend surveillance and unfit for surveillance. Standardised mortality ratios (SMR) were calculated for common causes of death. Cox proportional hazards models were used to determine which factors were associated with progression to OAC.

RESULTS

In total, 671 BO patients (61% male) were studied; 37 (76% male) were diagnosed with OAC. OAC incidence was 0.47% per annum and stable across three decades (1982-1991 0.56%, 1992-2001 0.46%, 2002-2012 0.41% (p = 0.8)). All-cause mortality was increased for the whole cohort (SMR 163(95% CI 145-183)). Mortality from OAC appeared higher in patients who failed to attend surveillance (SMR 3216(95% CI 1543-5916)) compared with surveyed (SMR 1753(95% CI 933-2998)) and those unfit for surveillance due to co-morbidity (SMR 440(95% CI 143-1025)). Multivariable analysis identified low-grade dysplasia (HR 4.4(95% CI 1.56-12.43), p = 0.005) and length of BO (HR 1.2(95% (1.1-1.3)), p < 0.001)) as associated with OAC.

CONCLUSIONS

Progression to OAC appeared stable over three decades at 0.47% per annum. Patients with BO had a modest increase in all-cause mortality and a large increase in OAC mortality, particularly if fit for surveillance. Low-grade dysplasia and the length of the BO segment were associated with developing OAC.