Protocol for a mixed-methods study to develop and feasibility test a digital system for the capture of patient-reported outcomes (PROs) in patients receiving chimeric antigen receptor T-cell (CAR-T) therapies (the PRO-CAR-T study)

INTRODUCTION

Chimeric antigen receptor (CAR) T-cell therapies are novel, potentially curative therapies for haematological malignancies. CAR T-cell therapies are associated with severe toxicities, meaning patients require monitoring during acute and postacute treatment phases. Electronic patient-reported outcomes (ePROs), self-reports of health status provided via online questionnaires, can complement clinician observation with potential to improve patient outcomes. This study will develop and evaluate feasibility of a new ePRO system for CAR-T patients in routine care.

METHODS AND ANALYSIS

Multiphase, mixed-methods study involving multiple stakeholder groups (patients, family members, carers, clinicians, academics/researchers and policy-makers). The intervention development phase comprises a Delphi study to select PRO measures for the digital system, a codesign workshop and consensus meetings to establish thresholds for notifications to the clinical team if a patient reports severe symptoms or side effects. Usability testing will evaluate how users interact with the digital system and, lastly, we will evaluate ePRO system feasibility with 30 CAR-T patients (adults aged 18+ years) when used in addition to usual care. Feasibility study participants will use the ePRO system to submit self-reports of symptoms, treatment tolerability and quality of life at specific time points. The CAR-T clinical team will respond to system notifications triggered by patients' submitted responses with actions in line with standard clinical practice. Feasibility measures will be collected at prespecified time points following CAR T-cell infusion. A qualitative substudy involving patients and clinical team members will explore acceptability of the ePRO system.

ETHICS AND DISSEMINATION

Favourable ethical opinion was granted by the Health and Social Care Research Ethics Committee B(HSC REC B) (ref: 23/NI/0104) on 28 September 2023. Findings will be submitted for publication in high-quality, peer-reviewed journals. Summaries of results, codeveloped with the Blood and Transplant Research Unit Patient and Public Involvement and Engagement group, will be disseminated to all interested groups.

TRIAL REGISTRATION NUMBER

ISCTRN11232653.

Safety of maintaining elective and emergency surgery during the COVID-19 pandemic with the introduction of a Protected Elective Surgical Unit (PESU): A cross-specialty evaluation of 30-day outcomes in 9,925 patients undergoing surgery in a University Health Board

Background

The COVID-19 pandemic has caused unprecedented health care challenges mandating surgical service reconfiguration. Within our hospital, emergency and elective streams were separated and self-contained Protected Elective Surgical Units were developed to mitigate against infection-related morbidity. Aims of this study were to determine the risk of COVID-19 transmission and mortality and whether the development of Protected Elective Surgical Units can result in significant reduction in risk.

Methods

A retrospective observational study of consecutive patients from 18 specialties undergoing elective or emergency surgery under general, spinal, or epidural anaesthetic over a 12-month study period was undertaken. Primary outcome measures were 30-day postoperative COVID-19 transmission rate and mortality. Secondary adjusted analyses were performed to ascertain hospital and Protected Elective Surgical Unit transmission rates.

Results

Between 15 March 2020 and 14 March 2021, 9,925 patients underwent surgery: 6,464 (65.1%) elective, 5,116 (51.5%) female, and median age 57 (39–70). A total of 69.5% of all procedures were performed in Protected Elective Surgical Units. Overall, 30-day postoperative COVID-19 transmission was 2.8% (3.4% emergency vs 1.2% elective P < .001). Protected Elective Surgical Unit postoperative transmission was significantly lower than non–Protected Elective Surgical Unit (0.42% vs 3.2% P < .001), with an adjusted likely in-hospital Protected Elective Surgical Unit transmission of 0.04%. The 30-day all-cause mortality was 1.7% and was 14.6% in COVID-19–positive patients. COVID-19 infection, age > 70, male sex, American Society of Anesthesiologists grade > 2, and emergency surgery were all independently associated with mortality.

Conclusion

This study has demonstrated that Protected Elective Surgical Units can facilitate high-volume elective surgical services throughout peaks of the COVID-19 pandemic while minimising viral transmission and mortality. However, mortality risk associated with perioperative COVID-19 infection remains high.

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).

276 Safety of Maintaining Elective and Emergency Surgery During the COVID-19 Pandemic with the Introduction of an Innovative Protected Elective Surgical Unit (PESU): A Cross-Specialty Evaluation of 30-Day Outcomes in 9925 Patients Undergoing Surgery in a University Health Board

Aim

High quality mobile health applications (mhealth apps) have the potential to enhance the prevention, diagnosis, and treatment of burns. The primary aim of this study was to evaluate whether the quality of mhealth apps for burns care is being adequately assessed. The secondary aim was to determine whether these apps meet UK regulatory standards.

Method

We searched AMED, BNI, CINAHL, Cochrane library, Embase, Emcare, Medline and PsychInfo to identify studies assessing mhealth app quality for burns. The PRISMA reporting guideline was adhered to. Two independent reviewers screened s to identify relevant studies. We analysed whether seven established domains of mhealth app quality were assessed: design, information/content, usability, functionality, ethical issues, security/privacy, and user-perceived value.

Results

Of the 28 included studies, none assessed all seven domains of quality. Design was assessed in 4/28 studies; information/content in 26/28 studies; usability in 12/28 studies; functionality in 10/28 studies; ethical issues were never assessed in any studies; security/privacy was not assessed; subjective assessment was made in 9/28 studies. 17/28 studies included apps that met the definition of ‘medical device’ according to MHRA guidance, yet only one app was appropriately certified with the UK Conformity Assessed (UKCA) mark.

Conclusions

The quality of mHealth apps for burns are not being adequately assessed. The majority of apps should be considered medical devices according to UK standards, but only one was appropriately certified. Regulatory bodies should support mhealth app developers, so as to improve quality control whilst simultaneously fostering innovation.

Paving the way for application of next generation risk assessment to safety decision-making for cosmetic ingredients

Next generation risk assessment (NGRA) is an exposure-led, hypothesis-driven approach that has the potential to support animal-free safety decision-making. However, significant effort is needed to develop and test the in vitro and in silico (computational) approaches that underpin NGRA to enable confident application in a regulatory context. A workshop was held in Montreal in 2019 to discuss where effort needs to be focussed and to agree on the steps needed to ensure safety decisions made on cosmetic ingredients are robust and protective. Workshop participants explored whether NGRA for cosmetic ingredients can be protective of human health, and reviewed examples of NGRA for cosmetic ingredients. From the limited examples available, it is clear that NGRA is still in its infancy, and further case studies are needed to determine whether safety decisions are sufficiently protective and not overly conservative. Seven areas were identified to help progress application of NGRA, including further investments in case studies that elaborate on scenarios frequently encountered by industry and regulators, including those where a ‘high risk’ conclusion would be expected. These will provide confidence that the tools and approaches can reliably discern differing levels of risk. Furthermore, frameworks to guide performance and reporting should be developed.

Facing the Ethical Challenges: Consumer Involvement in COVID-19 Pandemic Research

Consumer involvement in clinical research is an essential component of a comprehensive response during emergent health challenges. During the COVID-19 pandemic, the moderation of research policies and regulation to facilitate research may raise ethical issues. Meaningful, diverse consumer involvement can help to identify practical approaches to prioritize, design, and conduct rapidly developed clinical research amid current events. Consumer involvement might also elucidate the acceptability of flexible ethics review approaches that aim to protect participants whilst being sensitive to the challenging context in which research is taking place. This article describes the main ethical challenges arising from pandemic research and how involving consumers and the community could enable resolution of such issues.

A novel whole blood coagulometer for NOAC testing

Background

While use of the non-vitamin K antagonist oral anticoagulants (NOACs) does not currently require routine coagulation monitoring, this can be highly desirable in at-risk patients, including those suffering major trauma or having to undergo emergency surgery, especially when a NOAC reversal agent is used. However, a point-of-care (PoC) device for the rapid measurement of clotting times in patients on NOACs is currently not available.

Purpose

To characterize the sensitivity of a novel PoC coagulometer to NOAC-induced anticoagulation, as well as quantify instrument precision, via venous whole blood samples freshly spiked with rivaroxaban, apixaban and edoxaban.

Methods

This study was conducted using healthy volunteers with normal coagulation lab values, including PT/INR and aPTT, confirmed via laboratory testing. Whole blood samples from two volunteers per NOAC were spiked with either 0 (sham), 75, 150, or 300 ng/mL of rivaroxaban, apixaban or edoxaban, in randomized order, each day for five days of testing. Each day, each spiked sample was run on five PoC coagulometers simultaneously for replicate measurement.

Results

PoC coagulometer clotting times exhibited a high degree of linearity spanning the measuring range, with R2 values approaching 1, and high sensitivity across NOAC concentrations tested (i.e. each concentration was statistically significantly different from the others), as well as a high level of precision across the five days of testing. Furthermore, the PoC coagulometer yielded notably low %CVs at each concentration tested, for each subject and anticoagulant, ranging from approximately 3–7% (Fig. 1, rivaroxaban and apixaban data from individual subjects shown).

Conclusions

These results suggest that this PoC coagulometer could be a valuable tool to assess the pharmacodynamic effects of the NOACs in emergency and other settings. The PoC coagulometer yields results within minutes at a patient's bedside, requiring only a drop of whole blood.

Figure 1

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Perosphere Technologies Inc.

Variation in training requirements within general surgery: comparison of 23 countries

Background

Many differences exist in postgraduate surgical training programmes worldwide. The aim of this study was to provide an overview of the training requirements in general surgery across 23 different countries.

Methods

A collaborator affiliated with each country collected data from the country's official training body website, where possible. The information collected included: management, teaching, academic and operative competencies, mandatory courses, years of postgraduate training (inclusive of intern years), working‐hours regulations, selection process into training and formal examination.

Results

Countries included were Australia, Belgium, Canada, Colombia, Denmark, Germany, Greece, Guatemala, India, Ireland, Italy, Kuwait, the Netherlands, New Zealand, Russia, Saudi Arabia, South Africa, South Korea, Sweden, Switzerland, UK, USA and Zambia. Frameworks for defining the outcomes of surgical training have been defined nationally in some countries, with some similarities to those in the UK and Ireland. However, some training programmes remain heterogeneous with regional variation, including those in many European countries. Some countries outline minimum operative case requirement (range 60–1600), mandatory courses, or operative, academic or management competencies. The length of postgraduate training ranges from 4 to 10 years. The maximum hours worked per week ranges from 38 to 88 h, but with no limit in some countries.

Conclusion

Countries have specific and often differing requirements of their medical profession. Equivalence in training is granted on political agreements, not healthcare need or competencies acquired during training.

Safe management of surgical smoke in the age of COVID-19

Background

The COVID-19 global pandemic has resulted in a plethora of guidance and opinion from surgical societies. A controversial area concerns the safety of surgically created smoke and the perceived potential higher risk in laparoscopic surgery.

Methods

The limited published evidence was analysed in combination with expert opinion. A review was undertaken of the novel coronavirus with regards to its hazards within surgical smoke and the procedures that could mitigate the potential risks to healthcare staff.

Results

Using existing knowledge of surgical smoke, a theoretical risk of virus transmission exists. Best practice should consider the operating room set-up, patient movement and operating theatre equipment when producing a COVID-19 operating protocol. The choice of energy device can affect the smoke produced, and surgeons should manage the pneumoperitoneum meticulously during laparoscopic surgery. Devices to remove surgical smoke, including extractors, filters and non-filter devices, are discussed in detail.

Conclusion

There is not enough evidence to quantify the risks of COVID-19 transmission in surgical smoke. However, steps can be undertaken to manage the potential hazards. The advantages of minimally invasive surgery may not need to be sacrificed in the current crisis.

Developments in understanding and applying prebiotics in research and practice-an ISAPP conference paper

AIMS

The concept of using specific dietary components to selectively modulate the gut microbiota to confer a health benefit, defined as prebiotics, originated in 1995. In 2018, a group of scientists met at the International Scientific Association for Probiotics and Prebiotics annual meeting in Singapore to discuss advances in the prebiotic field, focussing on issues affecting functionality, research methodology and geographical differences.

METHODS AND RESULTS

The discussion ranged from examining scientific literature supporting the efficacy of established prebiotics, to the prospects for establishing health benefits associated with novel compounds, isolated from different sources.

CONCLUSIONS

While many promising candidate prebiotics from across the globe have been highlighted in preliminary research, there are a limited number with both demonstrated mechanism of action and defined health benefits as required to meet the prebiotic definition. Prebiotics are part of a food industry with increasing market sales, yet there are great disparities in regulations in different countries. Identification and commercialization of new prebiotics with unique health benefits means that regulation must improve and remain up-to-date so as not to risk stifling research with potential health benefits for humans and other animals.

SIGNIFICANCE AND IMPACT OF STUDY

This summary of the workshop discussions indicates potential avenues for expanding the range of prebiotic substrates, delivery methods to enhance health benefits for the end consumer and guidance to better elucidate their activities in human studies.

Comparison of recovery and outcome after left and right colectomy

AIM

The present study aimed to compare functional recovery and surgical outcomes after left and right colectomies.

METHOD

Consecutive elective left and right colon resections for benign and malignant indications, performed between 2011 and 2016 and recorded in a prospectively maintained enhanced recovery database, were analysed. Demographic and surgical items, as well as functional recovery and 30-day complications, were compared between left-sided and right-sided colectomies. Multivariable analysis was performed to identify risk factors for postoperative ileus (POI).

RESULTS

In total, 1001 left and 1041 right colectomies were comparable regarding demographic factors; only body mass index (BMI) was higher in patients undergoing left-sided resections (> 30 kg/m² : 33% vs 27%, P = 0.004). Malignancy (29% vs 67%, P < 0.001) and Crohn's disease (1% vs 31%, P < 0.001) were preponderant in right colectomies, whereas diverticular disease (68% vs 1%, P < 0.001) was the most common indication for left colectomy. Compliance with the enhanced recovery pathway (ERP) was comparable. While the minimally invasive approach was the preferred approach for both sides (61% vs 64%, P = 0.158), left colectomies took longer (180 ± 80 min vs 150 ± 70 min, P < 0.001), needed more perioperative fluids (3.1 ± 1.4 l vs 2.7 ± 1.5 l, P < 0.001) and resulted in greater postoperative weight gain (3.9 ± 6.5 kg vs 2.6 ± 6 kg, P = 0.025). Crohn's disease (OR = 2.64, 95% CI: 1.27-5.46) and fluid overload (OR = 2.02, 95% CI: 1.06-3.82) were independent risk factors for POI.

CONCLUSION

Despite equal ERP compliance, postoperative ileus was higher after right-sided colectomies. This finding was associated with Crohn's disease and fluid overload.

A systematic review of Clostridium difficile infection following reversal of ileostomy

AIM

The incidence of Clostridium difficile infection (CDI) has been reported to be as high as 4% following ileostomy reversal. CDI can be associated with significant morbidity. A systematic review on this subject has not been previously reported; our aim was to review the literature to establish incidence and to evaluate the factors that may contribute to an increased risk of CDI following ileostomy reversal.

METHOD

A systematic review of Ovid, Embase and Medline was undertaken. Search terms included C. difficile, reversal of ileostomy and ileostomy closure. Articles were included where at least one case of C. difficile-associated diarrhoea following reversal of defunctioning ileostomy was reported. Data extraction for articles was performed by two authors, using predefined data fields. The primary outcome measure was incidence of CDI amongst patients undergoing ileostomy reversal. Secondary outcomes were defunctioning time, antibiotic regime, acid suppression, time to onset of symptoms and study conclusions including colectomy and mortality rate.

RESULTS

Eleven articles were included (five case reports and six cohort studies). The overall incidence of CDI was 1.8% (242/13 728). The mean defunctioning time was 8.7 months (range 6-12). A variety of antibiotic regimes were described. Mean time to onset of symptoms was 6 days (range 3-14). Use of acid suppression, colectomy or mortality rate were frequently not reported.

CONCLUSION

CDI should be recognized as a potentially life-threatening complication of ileostomy closure. Careful consideration should be given to peri-operative antibiotic regime, acid suppression, timing of reversal and appropriate preoperative counselling of patients.

Hughes Abdominal Repair Trial (HART) - Abdominal wall closure techniques to reduce the incidence of incisional hernias: study protocol for a randomised controlled trial

Background

Incisional hernias are common complications of midline closure following abdominal surgery and cause significant morbidity, impaired quality of life and increased health care costs.

The ‘Hughes Repair’ combines a standard mass closure with a series of horizontal and two vertical mattress sutures within a single suture. This theoretically distributes the load along the incision length as well as across it. There is evidence to suggest that this technique is as effective as mesh repair for the operative management of incisional hernias; however, no trials have compared the Hughes Repair with standard mass closure for the prevention of incisional hernia formation following a midline incision.

Methods/design

This is a 1:1 randomised controlled trial comparing two suture techniques for the closure of the midline abdominal wound following surgery for colorectal cancer. Full ethical approval has been gained (Wales REC 3, MREC 12/WA/0374). Eight hundred patients will be randomised from approximately 20 general surgical units within the United Kingdom. Patients undergoing open or laparoscopic (more than a 5-cm midline incision) surgery for colorectal cancer, elective or emergency, are eligible. Patients under the age of 18 years, those having mesh inserted or undergoing musculofascial flap closure of the perineal defect in abdominoperineal wound closure, and those unable to give informed consent will be excluded. Patients will be randomised intraoperatively to either the Hughes Repair or standard mass closure. The primary outcome measure is the incidence of incisional hernias at 1 year as assessed by standardised clinical examination. The secondary outcomes include quality of life patient-reported outcome measures, cost-utility analysis, incidence of complete abdominal wound dehiscence and C-POSSUM scores. The incidence of incisional hernia at 1 year, assessed by computerised tomography, will form a tertiary outcome.

Discussion

A feasibility phase has been completed. The results of the study will be used to inform current and future practice and potentially reduce the risk of incisional hernia formation following midline incisions.

Trial registration

Trial Registration Number: ISRCTN 25616490. Registered on 1 January 2012.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-016-1573-0) contains supplementary material, which is available to authorized users.

Modular emergency general surgery training: A pilot study of a novel programme

Introduction Pan-speciality consensus guidance advocates mandatory emergency general surgery (EGS) training modules for specialist registrars (StRs). This pilot study evaluated the impact of EGS modules aimed at StRs over 1 year. Methods Eleven StRs were allocated a focused 4-week EGS module, in addition to the standard 1:12 on-call duty rota, in a tertiary surgical centre. Primary outcome measures included the number of indicative emergency operations and validated Procedure Based Assessments (PBAs) performed, both during the EGS module and over the training year. Results StRs performed a median of 11 (range 5-15) laparotomies during the EGS module versus 31 (range 9-49) over the whole training year. StRs attended 43.7% of available laparotomies during the module (range 24.1-63.7%). EGS modules provided more than one-third of the total emergency laparotomy experience, and a quarter of the emergency colectomy, appendicectomy and Hartmann's procedure experience. There were no differences in EGS module-related outcomes between junior and senior StRs. Significantly more PBAs related to laparotomy and segmental colectomy were completed during EGS modules than the on-call duty rota, at 32% versus 14% (p<0.001) and 48% versus 22% (p=0.019), respectively. Performance levels were maintained following module completion. Conclusions These findings provide an important baseline when considering future modular EGS training.

Nested renewal processes

A class of stochastic processes useful in the investigation of the deterioration and replacement of equipment, as well as in the study of group arrival/batch service queues, storage systems, epidemics and computer software, is introduced. These so-called nested renewal processes consist of ordinary and cumulative renewal processes sequentially nested within a hierarchy. The main properties of these processes are discussed with emphasis on the asymptotic results. An example of their application to tyre wear is considered.

Are general surgeons able to accurately self-assess their level of technical skills?

INTRODUCTION

Self-assessment is a way of improving technical capabilities without the need for trainer feedback. It can identify areas for improvement and promote professional medical development. The aim of this review was to identify whether self-assessment is an accurate form of technical skills appraisal in general surgery.

METHODS

The PubMed, MEDLINE(®), Embase(™) and Cochrane databases were searched for studies assessing the reliability of self-assessment of technical skills in general surgery. For each study, we recorded the skills assessed and the evaluation methods used. Common endpoints between studies were compared to provide recommendations based on the levels of evidence.

RESULTS

Twelve studies met the inclusion criteria from 22,292 initial papers. There was no level 1 evidence published. All papers compared the correlation between self-appraisal versus an expert score but differed in the technical skills assessment and the evaluation tools used. The accuracy of self-assessment improved with increasing experience (level 2 recommendation), age (level 3 recommendation) and the use of video playback (level 3 recommendation). Accuracy was reduced by stressful learning environments (level 2 recommendation), lack of familiarity with assessment tools (level 3 recommendation) and in advanced surgical procedures (level 3 recommendation).

CONCLUSIONS

Evidence exists to support the reliability of self-assessment of technical skills in general surgery. Several variables have been shown to affect the accuracy of self-assessment of technical skills. Future work should focus on evaluating the reliability of self-assessment during live operating procedures.

In vitro characterisation of the fermentation profile and prebiotic capacity of gold-fleshed kiwifruit

A new Actinidia chinensis gold-fleshed kiwifruit cultivar 'Zesy002' was tested to investigate whether it could positively modulate the composition of the human colonic microbiota. Digested Zesy002 kiwifruit was added to in vitro pH-controlled anaerobic batch fermenters that were inoculated with representative human faecal microbiota. Alterations to the gut microbial ecology were determined by 16S rRNA gene sequencing and metabolic end products were measured using gas chromatography and liquid chromatography - mass spectrometry. Results indicated a substantial shift in the composition of bacteria within the gut models caused by kiwifruit supplementation. Zesy002 supplemented microbiota had a significantly higher abundance of Bacteroides spp., Parabacteroides spp. and Bifidobacterium spp. after 48 h of fermentation compared with the start of the fermentation. Organic acids from kiwifruit were able to endure simulated gastrointestinal digestion and were detectable in the first 10 h of fermentation. The fermentable carbohydrates were converted to beneficial organic acids with a particular predilection for propionate production, corresponding with the rise in Bacteroides spp. and Parabacteroides spp. These results support the claim that Zesy002 kiwifruit non-digestible fractions can effect favourable changes to the human colonic microbial community and primary metabolites, and demonstrate a hitherto unknown effect of Zesy002 on colonic microbiota under in vitro conditions.

Choosing Wisely in the UK: the Academy of Medical Royal Colleges' initiative to reduce the harms of too much medicine

A Malhotra and colleagues explain how and why a US initiative to get doctors to stop using interventions with no benefit is being brought to the UK

D-dimer and risk of thromboembolic and bleeding events in patients with atrial fibrillation--observations from the ARISTOTLE trial

BACKGROUND

D-dimer is related to adverse outcomes in arterial and venous thromboembolic diseases.

OBJECTIVES

To evaluate the predictive value of D-dimer level for stroke, other cardiovascular events, and bleeds, in patients with atrial fibrillation (AF) treated with oral anticoagulation with apixaban or warfarin; and to evaluate the relationship between the D-dimer levels at baseline and the treatment effect of apixaban vs. warfarin.

METHODS

In the ARISTOTLE trial, 18 201 patients with AF were randomized to apixaban or warfarin. D-dimer was analyzed in 14 878 patients at randomization. The cohort was separated into two groups; not receiving vitamin K antagonist (VKA) treatment and receiving VKA treatment at randomization.

RESULTS

Higher D-dimer levels were associated with increased frequencies of stroke or systemic embolism (hazard ratio [HR] [Q4 vs. Q1] 1.72, 95% confidence interval [CI] 1.14-2.59, P = 0.003), death (HR [Q4 vs. Q1] 4.04, 95% CI 3.06-5.33) and major bleeding (HR [Q4 vs. Q1] 2.47, 95% CI 1.77-3.45, P < 0.0001) in the no-VKA group. Similar results were obtained in the on-VKA group. Adding D-dimer level to the CHADS2 score improved the C-index from 0.646 to 0.655 for stroke or systemic embolism, and from 0.598 to 0.662 for death, in the no-VKA group. D-dimer level improved the HAS-BLED score for prediction of major bleeds, with an increase in the C-index from 0.610 to 0.641. There were no significant interactions between efficacy and safety of study treatment and D-dimer level.

CONCLUSION

In anticoagulated patients with AF, the level of D-dimer is related to the risk of stroke, death, and bleeding, and adds to the predictive value of clinical risk scores. The benefits of apixaban were consistent, regardless of the baseline D-dimer level.

A new ex vivo animal simulation model for skills training in laparoscopic colorectal surgery

The opportunity for using simulation in medical training has expanded in recent years. 1–3 Laparoscopic surgery is an area that is ideally suited to the use of simulators for the acquisition of clinical skills. 4 Simulation allows educators to have control over pre-selected scenarios, without distressing patients or encountering complications. 5

The WIMAT colonoscopy suitcase model: a novel porcine polypectomy trainer

AIM

Simulation allows the acquisition of complex skills within a safe environment. Endoscopic polypectomy has a long learning curve. Our novel polypectomy simulator may be a useful adjunct for training. The aim of this study was to assess its content validity.

METHOD

The Welsh Institute for Minimal Access Therapy (WIMAT) endoscopy suitcase was designed to simulate colonic polypectomy. Participants from regional and national courses were recruited into the study. Each undertook a standardized simulated polypectomy and completed a seven-point Likert scale questionnaire examining its realism.

RESULTS

In all, 17 participants completed the questionnaire: 15 (88.2%) gastroenterologists, one (5.9%) colorectal surgeon and one (5.9%) experienced endoscopic nurse specialist. Of the gastroenterologists, seven (46.7%) were consultants and eight (53.3%) were senior trainees or Post CCT (Certificate of Completion of Training) fellows. The mean number of real-life polypectomies performed by the cohort was 156 (95% CI 35-355). The highest scores were for 'mucosal realism' (median score 6.0, P=0.001), 'endoscopic snare control' (median score 6.0, P=0.001), 'handling the polyp' (median score 6.0, P=0.001) and 'raising mucosa' (median score 6.0, P<0.001). Of the 15 parameters examined only three were not statistically significant in favour of the simulator. These were 'anatomical realism of sessile polyps', 'resistance of scope movement' and 'paradoxical motion'. The overall score for the simulation was 6.0 (P < 0.001). There was no significant difference between the level of difficulty of the simulator compared with real life (median score 4.0, P = 0.559).

CONCLUSION

The WIMAT colonoscopy suitcase model has excellent content validity for several parameters. This may have potential applications in medical training and assessment.

Future directions of stroke prevention in atrial fibrillation: the potential impact of novel anticoagulants and stroke risk stratification

Stroke prevention in atrial fibrillation is of paramount importance given its associated morbidity and mortality. The many challenges of warfarin limit its effective use in real-world clinical practice. We are entering an exciting therapeutic era as new classes of anticoagulants, including direct thrombin inhibitors, factor Xa inhibitors and novel vitamin K antagonists, are being evaluated for possible use in this patient population. If proven to be as efficacious as warfarin and safer, expanded use of these novel agents to lower risk subgroups may be justified. It is imperative that providers be aware of the many advantages and potential challenges posed by use of these novel agents in routine clinical care. An understanding of individual pharmacokinetic profiles and potential drug-drug and drug-disease interactions will translate into improved effectiveness in real-world practice.

The efficacy and safety of apixaban, an oral, direct factor Xa inhibitor, as thromboprophylaxis in patients following total knee replacement

BACKGROUND

Heparins and warfarin are currently used as venous thromboembolism (VTE) prophylaxis in surgery. Inhibition of factor (F) Xa provides a specific mechanism of anticoagulation and the potential for an improved benefit-risk profile.

OBJECTIVES

To evaluate the safety and efficacy of apixaban, a potent, direct, oral inhibitor of FXa, in patients following total knee replacement (TKR), and to investigate dose-response relationships.

PATIENTS/METHODS

A total of 1238 patients were randomized to one of six double-blind apixaban doses [5, 10 or 20 mg day(-1) administered as a single (q.d.) or a twice-daily divided dose (b.i.d.)], enoxaparin (30 mg b.i.d.) or open-label warfarin (titrated to an International Normalized Ratio of 1.8-3.0). Treatment lasted 10-14 days, commencing 12-24 h after surgery with apixaban or enoxaparin, and on the evening of surgery with warfarin. The primary efficacy outcome was a composite of VTE (mandatory venography) and all-cause mortality during treatment. The primary safety outcome was major bleeding.

RESULTS

A total of 1217 patients were eligible for safety and 856 patients for efficacy analysis. All apixaban groups had lower primary efficacy event rates than either comparator. The primary outcome rate decreased with increasing apixaban dose (P = 0.09 with q.d./b.i.d. regimens combined, P = 0.19 for q.d. and P = 0.13 for b.i.d. dosing).A significant dose-related increase in the incidence of total adjudicated bleeding events was noted in the q.d. (P = 0.01) and b.i.d. (P = 0.02) apixaban groups; there was no difference between q.d. and b.i.d. regimens.

CONCLUSIONS

Apixaban in doses of 2.5 mg b.i.d. or 5 mg q.d. has a promising benefit-risk profile compared with the current standards of care following TKR.

Factor Xa or thrombin: is factor Xa a better target?

Existing vitamin K antagonists (VKAs) have drawbacks that limit their effectiveness, safety, and overall frequency of use. Oral anticoagulants in development with targeted action against individual coagulation factors, specifically direct factor (F) Xa and IIa inhibitors, appear to have pharmacokinetic and pharmacodynamic properties that overcome the limitations of the VKAs. Based on the theory of how coagulation factors interact, on the results of in vitro studies, and on clinical outcomes, there is accumulating evidence that FXa may represent a better target for inhibition than FIIa. This is based on an understanding of the amplified nature of coagulation factor interactions and fibrin formation, the need for smaller doses of an anticoagulant to block coagulation progression earlier in the sequence of reactions, the evidence for incomplete suppression of thrombin generation with direct thrombin inhibitors, evidence for rebound hypercoagulability with thrombin inhibitors, and clinical results with the indirect, parenteral, FXa inhibitor (fondaparinux), as well as early phase II results of new oral Xa and IIa inhibitors compared with enoxaparin. The latter studies, although not comparative, provide some evidence for the effectiveness and safety of Xa inhibitors at a range of doses not seen with the direct IIa inhibitors.

Severe global DNA hypomethylation blocks differentiation and induces histone hyperacetylation in embryonic stem cells

It has been reported that DNA methyltransferase 1-deficient (Dnmt1-/-) embryonic stem (ES) cells are hypomethylated (20% CpG methylation) and die through apoptosis when induced to differentiate. Here, we show that Dnmt[3a-/-,3b-/-] ES cells with just 0.6% of their CpG dinucleotides behave differently: the majority of cells within the culture are partially or completely blocked in their ability to initiate differentiation, remaining viable while retaining the stem cell characteristics of alkaline phosphatase and Oct4 expression. Restoration of DNA methylation levels rescues these defects. Severely hypomethylated Dnmt[3a-/-,3b-/-] ES cells have increased histone acetylation levels, and those cells that can differentiate aberrantly express extraembryonic markers of differentiation. Dnmt[3a-/-,3b-/-] ES cells with >10% CpG methylation are able to terminally differentiate, whereas Dnmt1-/- ES cells with 20% of the CpG methylated cannot differentiate. This demonstrates that successful terminal differentiation is not dependent simply on adequate methylation levels. There is an absolute requirement that the methylation be delivered by the maintenance enzyme Dnmt1.

Interpretation with hindsight

In his 1965 paper 'DNA content of tumours: cytophotometric measurements', Sandritter was for the first time able to relate tumour DNA content to the pathology and progression of a small number of tumours. In subsequent publications, these observations were extended to the progression of a much more comprehensive range of tumours. The interpretation of Sandritter's paper below follows the increasing sophistication of methodologies for tumour DNA content through the existing publications and evaluates the conclusions and hypotheses Sandritter proposed in the light of the contemporary account.

Quality Assessment of Anticoagulation Dose Management: Comparative Evaluation of Measures of Time-in-Therapeutic Range

BACKGROUND

The results of clinical trials often hinge on the quality of oral anticoagulation management, yet the quality of such management is frequently not mentioned or measured. Time-in-therapeutic range (TTR) is one measure of quality of anticoagulation dose management, but various methodologies exist for measuring TTR.

OBJECTIVE

This study was initiated to compare three commonly used methodologies for measuring TTR to see how they compare within the same cohort of patients.

PATIENTS/METHODS

Three common methodologies of calculating time-in-therapeutic range were analyzed retrospectively in a cohort of patients over six two-month intervals. Additional analysis was performed for three and six-month intervals. The methodologies included fraction of INRs in range; cross-section of the files; and linear interpolation.

RESULTS

Fraction of the INRs in range and cross-section of the files methodologies gave similar results, while linear interpolation yielded significantly shorter time-in-range for the two-month, three-month, and six-month intervals measured. The advantages and disadvantages of each methodology are discussed.

CONCLUSIONS

The decision of which method to use should be based on clinic size, information desired, and clinic resources for ease of applying either of the methods in clinical practice. Each of these methodologies has their limitations and the question remains as to which method best reflects the quality of anticoagulation management. Regardless of these limitations, investigators are urged to employ at least one method of measuring the quality of oral anticoagulation management so as to better assess the validity of the clinical outcomes.

Feasibility and patients' acceptance of Home Automated Telemanagement of oral anticoagulation therapy

We developed the Home Automated Telemanagement (HAT) system for patients on oral anticoagulation therapy. It consists of a home unit, HAT server, and clinician unit. Patients at home use a palmtop or a laptop connected with a prothrombin time (PT) monitor. Each HAT session consists of self-testing, feedback, and educational components. The symptom data and PT/INR from patient homes are automatically sent to the HAT server and analyzed by the system. Patients who were seen in the Anticoagulation Clinic (N=29) were asked to use HAT in a laboratory setting. Semi-structured, in-depth interviews were used for the evaluation of HAT acceptance. 93% claimed that they would use such a tool at home and would advise other patients to use HAT for self-management and disease-specific education. Twelve patients used HAT at home for eight weeks. Compared to baseline, patients completing the home study showed statistically significant improvement in disease-specific quality of life dimensions of general satisfaction, self-efficacy, daily hassles, and distress. The Client Satisfaction Questionnaire demonstrated significant improvement in patient satisfaction with the treatment process. Our results demonstrated high acceptance of the HAT system by patients receiving long term anticoagulation therapy regardless of their previous computer experience or socioeconomic background.

Quantitative developmental anatomy of definitive haematopoietic stem cells/long-term repopulating units (HSC/RUs): role of the aorta-gonad-mesonephros (AGM) region and the yolk sac in colonisation of the mouse embryonic liver

In the developing mouse embryo the first definitive(transplantable-into-the-adult) haematopoietic stem cells/long-term repopulating units (HSC/RUs) emerge in the AGM region and umbilical vessels on 10-11 days post coitum (d.p.c.). Here, by limiting dilution analysis, we anatomically map the development of definitive HSC/RUs in different embryonic tissues during early colonisation of the liver. We show that by day 12 p.c. the mouse embryo contains about 66 definitive HSC/RUs (53 in the liver, 13 in other tissues), whereas on the previous day the total number of definitive HSC/RUs in the entire conceptus is only about 3. Owing to the length of the cell cycle this dramatic increase in the number of definitive HSC/RUs in only 24 hours is unlikely to be explained purely by cell division. Therefore,extensive maturation of pre-definitive HSCs to a state when they become definitive must take place in the day 11-12 embryo. Here we firstly identify the numbers of HSCs in various organs at 11-13 d.p.c. and secondly, using an organ culture approach, we quantitatively assess the potential of the aorta-gonadmesonephros (AGM) region and the yolk sac to produce/expand definitive HSC/RUs during days 11-12 of embryogenesis. We show that the capacity of the AGM region to generate definitive HSC/RUs is high on 11 d.p.c. but significantly reduced by 12 d.p.c. Conversely, at 12 d.p.c. the YS acquires the capacity to expand and/or generate definitive HSCs/RUs, whereas it is unable to do so on 11 d.p.c. Thus, the final steps in development of definitive HSC/RUs may occur not only within the AGM region, as was previously thought, but also in the yolk sac microenvironment. Our estimates indicate that the cumulative activity of the AGM region and the yolk sac is sufficient to provide the day 12 liver with a large number of definitive HSC/RUs,suggesting that the large pool of definitive HSC/RUs in day 12 foetal liver is formed predominantly by recruiting `ready-to-use' definitive HSC/RUs from extra-hepatic sources. In accordance with this we observe growing numbers of definitive HSC/RUs in the circulation during days 11-13 of gestation,suggesting a route via which these HSCs migrate.

Short-range attractiveness of pregnant women to Anopheles gambiae mosquitoes

Malaria is a major cause of illness and an indirect cause of mortality in pregnant women. It can also cause stillbirths and low-birthweight babies. We have shown previously that pregnant women attracted twice as many Anopheles gambiae mosquitoes, the principal African malaria vector, as their non-pregnant counterparts over distances of about 15 m. In the current study (in 1998/99) we compared the short-range attractiveness of both pregnant and non-pregnant women sleeping under untreated bednets in Gambian villages. First, we measured the rate of mosquito entry under bednets and, second, we calculated the proportion of mosquitoes biting mothers under each bednet compared to their children. The feeding preference of An. gambiae collected under nets was determined by DNA fingerprinting blood samples from human subjects sleeping under each bednet and comparing these to fingerprints obtained from mosquito bloodmeals. Pregnant women were more attractive to An. gambiae mosquitoes than non-pregnant women under an untreated bednet. The number of mosquitoes entering bednets each night was 1.7-4.5 times higher in the pregnant group (P = 0.02) and pregnant women also received a higher proportion of bites under the bednets than did non-pregnant women (70% vs 52%, P = 0.001). This study clearly demonstrates that pregnant women are more exposed to malaria parasites than other women, which contributes to the greater vulnerability of pregnant women to malaria.

Comparative cost-effectiveness of diagnostic tests for urinary schistosomiasis and the implications for school health programmes

The use of self-reported schistosomiasis or blood in urine has received a great deal of interest as a cheap and simple technique for diagnosing individuals infected with Schistosoma haematobium and identifying schools with a high prevalence of infection. Although the answers to questions about the signs and symptoms of urinary schistosomiasis have been shown to be good markers of parasitological infection, a formal cost-effectiveness analysis of their performance in relation to urine filtration and parasitological examination (assumed to be the gold standard) is lacking. Using empirical data on the costs and effectiveness of these techniques in 15 schools in Tanzania, the cost for every correct diagnosis or for every infected child identified was assessed. Although self-reported schistosomiasis was shown to be three times more cost-effective than urine filtration in identifying infected individuals, it would have resulted in a third of the infected children being missed. Use of self-reported schistosomiasis first to identify high-risk schools for mass treatment and then to identify infected children in low-risk schools (for individual treatment) also appeared more cost-effective than urine filtration and would have resulted in only 8% of the infected children not being treated. The use of self-reported schistosomiasis or self-reported blood in urine should be continually supported as a simple, cheap and cost-effective tool for identifying schools at high-risk of schistosomiasis.

The effects of sex and age of responders on the reliability of self-diagnosed infection: a study of self-reported urinary schistosomiasis in Tanzanian school children

Self-reported schistosomiasis has been proven to be a reliable estimation of the prevalence of infection in school children. For the first time, this paper presents an investigation into the use of self-reported schistosomiasis to estimate the prevalence of urinary schistosomiasis, due to Schistosoma haematobium, in school children with particular emphasis on whether the age and sex of respondents influences the reliability of diagnosis. It is shown first, that the prevalence and intensity of infection vary with sex; infection in boys is always more prevalent and more intense than in girls of the same age and second, that age and sex influence the reliability of self-reported schistosomiasis as a diagnostic method. Age and sex are factors that should be considered when implementing control measures in endemic areas.