Monitoring environmental microbiomes: Alignment of microbiology and computational biology competencies within a culturally integrated curriculum and research framework

We have developed a flexible undergraduate curriculum that leverages the place-based research of environmental microbiomes to increase the number of Indigenous researchers in microbiology, data science and scientific computing. Monitoring Environmental Microbiomes (MEM) provides a curriculum and research framework designed to integrate an Indigenous approach when conducting authentic scientific research and to build interest and confidence at the undergraduate level. MEM has been successfully implemented as a short summer workshop to introduce computing practices in microbiome analysis. Based on self-assessed student knowledge of topics and skills, increased scientific confidence and interest in genomics careers were observed. We propose MEM be incorporated in a scalable course-based research experience for undergraduate institutions, including tribal colleges and universities, community colleges and other minority serving institutions. This coupled curricular and research framework explicitly considers cultural perspectives, access and equity to train a diverse future workforce that is more informed to engage in microbiome research and to translate microbiome science to benefit community and environmental health.

353 Patients with N2 Non-Small Cell Primary Lung Cancer, Does Surgery Offer an Advantage?

Background

Non-small cell lung cancer (NSCLC) is one of two histological types of lung cancers. Evidence-based guidelines recommend radical resection in early-stage lung cancer, N2 disease is when there is moderately advanced lymph node spread of the cancer, recommendations for surgery at this stage are more contested.

Aim

This was a service evaluation of the management of patients with NSCLC N2 disease. We aimed to evaluate the management and outcomes of these patients to see whether surgery offers an advantage over other modalities.

Method

This was a retrospective cohort study reviewing patients treated at University Hospital Southampton (UHS) who were diagnosed with N2 NSCLC before the start of treatment from 2016–2018 and comparing survival of surgically managed patients with those treated in other ways.

Results

50 N2 patients were included, 32 had radical treatment and 11 of these underwent surgery. Kaplan-Meier survival analysis showed no significant statistical difference (Log rank = 2.342 p = 0.679) between surgery and other treatments, the survival plots showed a slightly better initial survival for chemoradiotherapy. Men were statistically more likely to have squamous cell carcinomas than women who had more adenocarcinomas. PS was shown to have significant effect on survival with higher PS having a worse survival.

Conclusions

We didn't find a statistically significant difference in the survival between patients managed surgically and other modalities. PS's effect on survival reiterates its importance when deciding on treatments to offer patients.

Glutaredoxins regulate maize inflorescence meristem development via redox control of TGA transcriptional activity

Glutaredoxins (GRXs) are small oxidoreductases that can modify target protein activities through control of the redox (reduction/oxidation) state by reducing or glutathionylating disulfide bridges. Although CC-type GRXs are plant specific and play important roles in many processes, the mechanisms by which they modulate the activity of target proteins in vivo are unknown. In this study, we show that a maize CC-type GRX, MALE STERILE CONVERTED ANTHER1 (MSCA1), acts redundantly with two paralogues, ZmGRX2 and ZmGRX5, to modify the redox state and the activity of its putative target, the TGA transcription factor FASCIATED EAR4 (FEA4) that acts as a negative regulator of inflorescence meristem development. We used CRISPR-Cas9 to create a GRX triple knockout, resulting in severe suppression of meristem, ear and tassel growth and reduced plant height. We further show that GRXs regulate the redox state, DNA accessibility and transcriptional activities of FEA4, which acts downstream of MSCA1 and its paralogues to control inflorescence development. Our findings reveal the function of GRXs in meristem development, and also provide direct evidence for GRX-mediated redox modification of target proteins in plants.

Frequentist rules for regulatory approval of subgroups in phase III trials: A fresh look at an old problem

Background

The number of Phase III trials that include a biomarker in design and analysis has increased due to interest in personalised medicine. For genetic mutations and other predictive biomarkers, the trial sample comprises two subgroups, one of which, say B+ is known or suspected to achieve a larger treatment effect than the other B−. Despite treatment effect heterogeneity, trials often draw patients from both subgroups, since the lower responding B− subgroup may also gain benefit from the intervention. In this case, regulators/commissioners must decide what constitutes sufficient evidence to approve the drug in the B− population.

Methods and Results

Assuming trial analysis can be completed using generalised linear models, we define and evaluate three frequentist decision rules for approval. For rule one, the significance of the average treatment effect in B− should exceed a pre-defined minimum value, say ZB−>L. For rule two, the data from the low-responding group B− should increase statistical significance. For rule three, the subgroup-treatment interaction should be non-significant, using type I error chosen to ensure that estimated difference between the two subgroup effects is acceptable. Rules are evaluated based on conditional power, given that there is an overall significant treatment effect. We show how different rules perform according to the distribution of patients across the two subgroups and when analyses include additional (stratification) covariates in the analysis, thereby conferring correlation between subgroup effects.

Conclusions

When additional conditions are required for approval of a new treatment in a lower response subgroup, easily applied rules based on minimum effect sizes and relaxed interaction tests are available. Choice of rule is influenced by the proportion of patients sampled from the two subgroups but less so by the correlation between subgroup effects.

Pre-existing influenza-specific nasal IgA or nasal viral infection does not affect live attenuated influenza vaccine immunogenicity in children

The United Kingdom has a national immunization programme which includes annual influenza vaccination in school-aged children, using live attenuated influenza vaccine (LAIV). LAIV is given annually, and it is unclear whether repeat administration can affect immunogenicity. Because LAIV is delivered intranasally, pre-existing local antibody might be important. In this study, we analysed banked samples from a study performed during the 2017/18 influenza season to investigate the role of pre-existing influenza-specific nasal immunoglobulin (Ig)A in children aged 6-14 years. Nasopharyngeal swabs were collected prior to LAIV immunization to measure pre-existing IgA levels and test for concurrent upper respiratory tract viral infections (URTI). Oral fluid samples were taken at baseline and 21-28 days after LAIV to measure IgG as a surrogate of immunogenicity. Antibody levels at baseline were compared with a pre-existing data set of LAIV shedding from the same individuals, measured by reverse transcription-polymerase chain reaction. There was detectable nasal IgA specific to all four strains in the vaccine at baseline. However, baseline nasal IgA did not correlate with the fold change in IgG response to the vaccine. Baseline nasal IgA also did not have an impact upon whether vaccine virus RNA was detectable after immunization. There was no difference in fold change of antibody between individuals with and without an URTI at the time of immunization. Overall, we observed no effect of pre-existing influenza-specific nasal antibody levels on immunogenicity, supporting annual immunization with LAIV in children.

Are Gypsy Roma Traveller communities indigenous and would identification as such better address their public health needs?

INTRODUCTION

Across Europe, large numbers of Gypsy Roma Traveller communities experience significant health inequities such as higher morbidity, mortality and infant mortality. This health inequity is perpetuated by wider determinants such as a lower social status, lower educational attainment and substandard accommodation. This is not dissimilar to other indigenous peoples, even though many Gypsy Roma Traveller communities are not identified as indigenous.

METHODS

This article presents contemporary literature and research alongside the internationally agreed principles of indigenous peoples, examining similarities between Gypsy Roma Traveller communities and other indigenous peoples.

RESULTS

We argue that Gypsy Roma Traveller communities could be recognised as indigenous in terms of the internationally agreed principles of indigeneity and shared experiences of health inequity, colonisation and cultural genocide. Doing so would enable a more robust public health strategy and development of public health guidelines that take into account their cultural views and practices.

CONCLUSION

Recognising Gypsy Roma Traveller communities in this way is important, especially concerning public health, as formal recognition of indigeneity provides certain rights and protection that can be used to develop appropriate public health strategies. Included within this are more nuanced approaches to promoting health, which focus on strengths and assets rather than deficit constructs that can perpetuate problematising of these communities.

Lung nodules are reliably detectable on ultra-low-dose CT utilising model-based iterative reconstruction with radiation equivalent to plain radiography

AIM

To determine if ultra-low-dose (ULD) computed tomography (CT) utilising model-based iterative reconstruction (MBIR) with radiation equivalent to plain radiography allows the detection of lung nodules.

MATERIALS AND METHODS

Ninety-nine individuals undergoing surveillance of solid pulmonary nodules undertook a low-dose (LD) and ULD CT during the same sitting. Image pairs were read blinded, in random order, and independently by two experienced thoracic radiologists. With LD-CT as the reference standard, the number, size, and location of nodules was compared, and inter-rater agreement was established.

RESULTS

There was very good inter-rater agreement with regards nodules ≥4mm for both the LD- (k=0.931) and ULD-CT (k=0.869). One hundred and ninety-nine nodules were reported on the LD-CT by both radiologists and 196 reported on the ULD-CT, with no nodules reported only on the ULD-CT. This gives a sensitivity of 98.5% and specificity of 100% for ULD-CT with MBIR. The effective dose of radiation was significantly different between the two scans (p<0.0001), 1.67 mSv for the LD-CT and 0.13 mSv for the ULD-CT.

CONCLUSION

ULD-CT utilising MBIR and delivering radiation equivalent to plain radiography, allows detection of lung nodules with high sensitivity. The attendant 10-fold reduction in radiation may allow for dramatic reductions in cumulative radiation exposure.

A Cross-Sectional Investigation of Cognition and Ultrasound-Based Vascular Strain Indices

OBJECTIVE

We examine the relationship between variability in the plaque strain distribution estimated using ultrasound with multiple cognitive domains including executive, language, visuospatial reasoning, and memory function.

METHOD

Asymptomatic (n = 42) and symptomatic (n = 34) patients with significant (>60%) carotid artery stenosis were studied for plaque instability using ultrasound strain imaging and multiple cognitive domains including executive, language, visuospatial reasoning, and memory function. Correlation and ROC analyses were performed between ultrasound strain indices and cognitive function. Strain indices and cognition scores were also compared between symptomatic and asymptomatic patients to determine whether there are significant group differences.

RESULTS

Association of high-strain distributions with dysexecutive function was observed in both asymptomatic and symptomatic patients. For memory, visuospatial, and language functions, the correlations between strain and cognition were weaker for the asymptomatic compared to symptomatic group.

CONCLUSIONS

Both asymptomatic and symptomatic patients demonstrate a relationship between vessel strain indices and executive function indicating that silent strokes and micro-emboli could initially contribute to a decline in executive function, whereas strokes and transient ischemic attacks may cause the further decline in other cognitive functions.

Leadership and the functioning of maternal health services in two rural district hospitals in South Africa

Maternal mortality remains high in Eastern Cape Province, South Africa, despite over 90% of pregnant women utilizing maternal health services. A recent survey showed wide variation in performance among districts in the province. Heterogeneity was also found at the district level, where maternal health outcomes varied considerably among district hospitals. In ongoing research, leadership emerged as one of the key health systems factors affecting the performance of maternal health services at facility level. This article reports on a subsequent case study undertaken to examine leadership practices and the functioning of maternal health services in two resource-limited hospitals with disparate maternal health outcomes. An exploratory mixed-methods case study was undertaken with the two rural district hospitals as the units of analysis. The hospitals were purposively selected based on their maternal health outcomes: one reported good maternal health outcomes (pseudonym: Chisomo) and the other had poor outcomes (pseudonym: Tinyade). Comparative data were collected through a facility survey, non-participant observation of management and perinatal meetings, record reviews and interviews with hospital leadership, staff and patients to elicit information about leadership practices including supervision, communication and teamwork. Descriptive and thematic data analysis was undertaken. The two hospitals had similar infrastructure and equipment. Hospital managers at Chisomo used their innovation and entrepreneurial skills to improve quality of care, and leadership style was described as supportive, friendly, approachable but 'firm'. They also undertook frequent and supportive supervisory meetings. Each department at Chisomo developed its own action plan and used data to monitor their actions. Good performers were acknowledged in group meetings. Staff in this facility were motivated and patients were happy about the quality of services. The situation was different at Tinyade hospital. Participants described the leadership style of their senior managers as authoritarian. Managers were rarely available in the office and did not hold regular meetings, leading to poor communication across teams and poor coordination to address resource constraints. This demotivated the staff. The differences in leadership style, structures, processes and work culture affected teamwork, managerial supervision and support. The study demonstrates how leadership styles and practices influence maternal health care services in resource limited hospitals. Supportive leadership manifested itself in the form of focused efforts to build teamwork, enhance entrepreneurship and in management systems that are geared to improving maternal care.

The drivers of sea lice management policies and how best to integrate them into a risk management strategy: An ecosystem approach to sea lice management

The control of sea lice infestations on cultivated Atlantic salmon is a major issue in many regions of the world. The numerous drivers which shape the priorities and objectives of the control strategies vary for different regions/jurisdictions. These range from the animal welfare and economic priorities of the producers, to the mitigation of any potential impacts on wild stocks. Veterinary ethics, environmental impacts of therapeutants, and impacts for organic certification of the produce are, amongst others, additional sets of factors which should be considered. Current best practice in both EU and international environmental law advocates a holistic ecosystem approach to assessment of impacts and risks. The issues of biosecurity and ethics, including the impacts on the stocks of species used as cleaner fish, are areas for inclusion in such a holistic ecosystem assessment. The Drivers, Pressures, State, Impacts, Responses (DPSIR) process is examined as a decision-making framework and potential applications to sea lice management are outlined. It is argued that this is required to underpin any integrated sea lice management (ISLM) strategy to balance pressures and outcomes and ensure a holistic approach to managing the issue of sea lice infestations on farmed stock on a medium to long-term basis.

Prolonged and large outbreak of invasive group A Streptococcus disease within a nursing home: repeated intrafacility transmission of a single strain

OBJECTIVES

Multiple invasive group A Streptococcus (GAS) infections were reported to public health by a skilled nursing facility (facility A) in Illinois between May 2014 and August 2016. Cases continued despite interventions including antibiotic prophylaxis for all residents and staff. Two other geographically close facilities reported contemporaneous outbreaks of GAS. We investigated potential reasons for ongoing transmission.

METHODS

We obtained epidemiologic data from chart review of cases and review of facility and public health records from previous investigations into the outbreak. Infection control practices at facility A were observed and evaluated. Whole genome sequencing followed by phylogenetic analysis was performed on available isolates from the three facilities.

RESULTS

From 2014 to 2016, 19 invasive and 60 noninvasive GAS infections were identified at facility A occurring in three clusters. Infection control evaluations during clusters 2 and 3 identified hand hygiene compliance rates of 14% to 25%, appropriate personal protective equipment use in only 33% of observed instances, and deficient wound-care practices. GAS isolates from residents and staff of all three facilities were subtype emm89.0; on phylogenetic analysis, facility A isolates were monophyletic and distinct.

CONCLUSIONS

Inadequate infection control and improper wound-care practices likely led to this 28-month-long outbreak of severe infections in a skilled nursing facility. Whole genome sequencing and phylogenetic analysis suggested that intrafacility transmission of a single highly transmissible GAS strain was responsible for the outbreak in facility A. Integration of genomic epidemiology tools with traditional epidemiology and infection control assessments was helpful in investigation of a facility-wide outbreak.

Genetic fingerprinting of salmon louse (Lepeophtheirus salmonis) populations in the North-East Atlantic using a random forest classification approach

Caligid sea lice represent a significant threat to salmonid aquaculture worldwide. Population genetic analyses have consistently shown minimal population genetic structure in North Atlantic Lepeophtheirus salmonis, frustrating efforts to track louse populations and improve targeted control measures. The aim of this study was to test the power of reduced representation library sequencing (IIb-RAD sequencing) coupled with random forest machine learning algorithms to define markers for fine-scale discrimination of louse populations. We identified 1286 robustly supported SNPs among four L. salmonis populations from Ireland, Scotland and Northern Norway. Only weak global structure was observed based on the full SNP dataset. The application of a random forest machine-learning algorithm identified 98 discriminatory SNPs that dramatically improved population assignment, increased global genetic structure and resulted in significant genetic population differentiation. A large proportion of SNPs found to be under directional selection were also identified to be highly discriminatory. Our data suggest that it is possible to discriminate between nearby L. salmonis populations given suitable marker selection approaches, and that such differences might have an adaptive basis. We discuss these data in light of sea lice adaption to anthropogenic and environmental pressures as well as novel approaches to track and predict sea louse dispersal.

Single-cell studies of IFN-β promoter activation by wild-type and NS1-defective influenza A viruses

Deletion or truncation of NS1, the principal IFN antagonist of influenza viruses, leads to increased IFN induction during influenza virus infection. We have studied activation of the IFN induction cascade by both wild-type and NS1-defective viruses at the single-cell level using a cell line expressing GFP under the control of the IFN-β promoter and by examining MxA expression. The IFN-β promoter was not activated in all infected cells even during NS1-defective virus infections. Loss of NS1 expression is therefore insufficient per se to induce IFN in an infected cell, and factors besides NS1 expression status must dictate whether the IFN response is activated. The IFN response was efficiently stimulated in these cells following infection with other viruses; the differential IFN response we observe with influenza viruses is therefore not cell specific but is likely due to differences in the nature of the infecting virus particles and their subsequent replication.

A study of wrist-worn activity measurement as a potential real-world biomarker for late-life depression

BACKGROUND

Late-life depression (LLD) is associated with a decline in physical activity. Typically this is assessed by self-report questionnaires and, more recently, with actigraphy. We sought to explore the utility of a bespoke activity monitor to characterize activity profiles in LLD more precisely.

METHOD

The activity monitor was worn for 7 days by 29 adults with LLD and 30 healthy controls. Subjects underwent neuropsychological assessment and quality of life (QoL) (36-item Short-Form Health Survey) and activities of daily living (ADL) scales (Instrumental Activities of Daily Living Scale) were administered.

RESULTS

Physical activity was significantly reduced in LLD compared with controls (t = 3.63, p < 0.001), primarily in the morning. LLD subjects showed slower fine motor movements (t = 3.49, p < 0.001). In LLD patients, activity reductions were related to reduced ADL (r = 0.61, p < 0.001), lower QoL (r = 0.65, p < 0.001), associative learning (r = 0.40, p = 0.036), and higher Montgomery-Åsberg Depression Rating Scale score (r = -0.37, p < 0.05).

CONCLUSIONS

Patients with LLD had a significant reduction in general physical activity compared with healthy controls. Assessment of specific activity parameters further revealed the correlates of impairments associated with LLD. Our study suggests that novel wearable technology has the potential to provide an objective way of monitoring real-world function.

Sudden cardiac death in adults with congenitally corrected transposition of the great arteries

Background

Congenitally corrected transposition of the great arteries (ccTGA) is a rare congenital heart disease. There have been only few reports of sudden cardiac death (SCD) in patients with ccTGA and reasonable ventricular function.

Methods

A retrospective review of the medical records of all patients attending our adult congenital heart centre, with known ccTGA.

Results

From a database of over 3500 adult patients with congenital heart disease, we identified 39 (∼1%) with ccTGA and ‘two-ventricle’ circulations. 65% were male. The mean age at diagnosis was 12.4±11.4 years and the mean age at last time of review was 34.3±11.3 years. 24 patients (56%) had a history of surgical intervention. 8 (19%) had had pacemaker implantation and 2 had had a defibrillator implanted for non-sustained ventricular tachycardia (NSVT). In 544 years of patient follow-up, there had been five cases of SCD in our population; 1 death per 109 patient-years. Two of these patients had had previously documented supraventricular or NSVT. However, they were all classified as New York Heart Association (NYHA) class I or II, and systemic (right) ventricular function had been recorded as normal, mildly or mildly–moderately impaired, at most recent follow-up.

Conclusions

Our experience suggests the need for improved risk stratification and/or surveillance for malignant arrhythmia in adults with ccTGA, even in those with reasonable functional class on ventricular function.

The Clinical and Bacteriological Assessment of a Twice Daily Formulation of Erythromycin Stearate: A General Practice Study

This report presents the clinical and bacteriological assessment of a twice daily formulation of erythromycin stearate. The activity of this twice daily formulation was compared with erythromycin stearate 250 mg 6 hourly, and the assessment carried out in a number of general practices, both urban and rural, distributed widely throughout the United Kingdom. The twice daily dosage regime of ‘Erythrocin 500’ was seen to be an effective therapy, to compare favourably with the smaller dose given 6 hourly and with minimal side-effects. Antibiotic sensitivity tests included penicillin and tetracycline as well as erythromycin, and the negligible incidence of resistance demonstrated for erythromycin contrasted with that of the two other commonly used antibiotics.

Systematic review and meta-analysis of the association between frailty and outcome in surgical patients

INTRODUCTION

Frailty is becoming increasingly prevalent in the elderly population although a lack of consensus regarding a clinical definition hampers comparison of clinical studies. More elderly patients are being assessed for surgical intervention but the effect of frailty on surgical related outcomes is still not clear.

METHODS

A systematic literature search for studies prospectively reporting frailty and postoperative outcomes in patients undergoing surgical intervention was performed with data collated from a total of 12 studies. Random effects meta-analysis modelling was undertaken to estimate the association between frailty and mortality rates (in-hospital and one-year), length of hospital stay and the need for step-down care for further rehabilitation/nursing home placement.

RESULTS

Frailty was associated with a higher in-hospital mortality rate (pooled odds ratio [OR]: 2.77, 95% confidence interval [CI]: 1.62-4.73), a higher one-year mortality rate (pooled OR: 1.99, 95% CI: 1.49-2.66), a longer hospital stay (pooled mean difference: 1.05 days, 95% CI: 0.02-2.07 days) and a higher discharge rate to further rehabilitation/step-down care (pooled OR: 5.71, 95% CI: 3.41-9.55).

CONCLUSIONS

The presence of frailty in patients undergoing surgical intervention is associated with poorer outcomes with regard to mortality and return to independence. Further in-depth studies are required to identify factors that can be optimised to reduce the burden of frailty in surgical patients.

Strain features and distributions in pneumococci from children with invasive disease before and after 13-valent conjugate vaccine implementation in the USA

The effect of second-generation pneumococcal conjugate vaccines on invasive pneumococcal disease (IPD) strain distributions have not yet been well described. We analysed IPD isolates recovered from children aged <5 years through Active Bacterial Core surveillance before (2008–2009; n = 828) and after (2011–2013; n = 600) 13-valent pneumococcal conjugate vaccine (PCV13) implementation. We employed conventional testing, PCR/electrospray ionization mass spectrometry and whole genome sequence (WGS) analysis to identify serotypes, resistance features, genotypes, and pilus types. PCV13, licensed in February 2010, effectively targeted all major 19A and 7F genotypes, and decreased antimicrobial resistance, primarily owing to removal of the 19A/ST320 complex. The strain complex contributing most to the remaining β-lactam resistance during 2011–2013 was 35B/ST558. Significant emergence of non-vaccine clonal complexes was not evident. Because of the removal of vaccine serotype strains, positivity for one or both pilus types (PI-1 and PI-2) decreased in the post-PCV13 years 2011–2013 relative to 2008–2009 (decreases of 32–55% for PI-1, and >95% for PI-2 and combined PI-1 + PI-2). β-Lactam susceptibility phenotypes correlated consistently with transpeptidase region sequence combinations of the three major penicillin-binding proteins (PBPs) determined through WGS analysis. Other major resistance features were predictable by DNA signatures from WGS analysis. Multilocus sequence data combined with PBP combinations identified progeny, serotype donors and recipient strains in serotype switch events. PCV13 decreased the frequency of all PCV13 serotype clones and concurrently decreased the frequency of strain subsets with resistance and/or adherence features conducive to successful carriage. Our results serve as a reference describing key features of current paediatric IPD strains in the USA after PCV13 implementation.

Why are Children Still Being Infected with HIV? Impact of an Integrated Public Health and Clinical Practice Intervention on Mother-to-Child HIV Transmission in Las Vegas, Nevada, 2007-2012

Background:

During a 9 months period, September 2005 through June 2006, Nevada documented six cases of pediatric HIV acquired through mother-to-child transmission. Subsequently, a community-based approach to the care of women and children living with or exposed to HIV was implemented.

Subjects and Methods:

A detailed review of mother-infant pairs where HIV transmission occurred was performed to identify missed opportunities for prevention of mother-to-child HIV transmission. An intervention program was developed and implemented using the six-step process. Data were collected prospectively over a 6 years period (2007–2012) and were evaluated for six core outcomes measures: (1) adequacy of prenatal care (2) HIV diagnoses of expectant mothers prior to delivery (3) appropriate use of antiretroviral (ARV) therapy before delivery (4) appropriate use of cesarean section for delivery (5) adequacy of zidovudine prophylaxis to newborn (6) HIV transmission rate.

Results:

Twenty-six infants were born to HIV-infected mothers from July 2005 to June 2006 with 6 documented infections. One hundred and five infants were born to HIV infected mothers from January 2007 to December 2012. Postimplementation, adequacy of prenatal care increased from 58% (15/26) to 85% (89/105); appropriate use of ARV therapy before delivery increased from 73% (19/26) to 86% (90/105); cesarean section as the method for delivery increased from 62% (16/26) to 74% (78/105); adequacy of zidovudine prophylaxis to newborn increased from 54% (14/26) to 87% (91/105). HIV transmission rate dropped from 23% (6/26) to 0%.

Conclusion:

Integrating public health and clinical services in the care of HIV-infected pregnant women and exposed infants leads to better coordination of care and improved quality of care.

Systematic Review and Meta-analysis of Long-term survival After Elective Infrarenal Abdominal Aortic Aneurysm Repair 1969-2011: 5 Year Survival Remains Poor Despite Advances in Medical Care and Treatment Strategies

Background

Improved critical care, pre-operative optimization, and the advent of endovascular surgery (EVAR) have improved 30 day mortality for elective abdominal aortic aneurysm (AAA) repair. It remains unknown whether this has translated into improvements in long-term survival, particularly because these factors have also encouraged the treatment of older patients with greater comorbidity. The aim of this study was to quantify how 5 year survival after elective AAA repair has changed over time.

Methods

A systematic review was performed identifying studies reporting 5 year survival after elective infrarenal AAA repair. An electronic search of the Embase and Medline databases was conducted to January 2014. Thirty-six studies, 60 study arms, and 107,814 patients were identified. Meta-analyses were conducted to determine 5 year survival and to report whether 5 year survival changed over time.

Results

Five-year survival was 69% (95% CI 67 to 71%, I² = 87%). Meta-regression on study midpoint showed no improvement in 5 year survival over the period 1969–2011 (log OR −0.001, 95% CI −0.014–0.012). Larger average aneurysm diameter was associated with poorer 5 year survival (adjusted log OR −0.058, 95% CI −0.095 to −0.021, I² = 85%). Older average patient age at surgery was associated with poorer 5 year survival (adjusted log OR −0.118, 95% CI −0.142 to −0.094, I² = 70%). After adjusting for average patient age, an improvement in 5 year survival over the period that these data spanned was obtained (adjusted log OR 0.027, 95% CI 0.012 to 0.042).

Conclusion

Five-year survival remains poor after elective AAA repair despite advances in short-term outcomes and is associated with AAA diameter and patient age at the time of surgery. Age-adjusted survival appears to have improved; however, this cohort as a whole continues to have poor long-term survival. Research in this field should attempt to improve the life expectancy of patients with repaired AAA and to optimise patient selection.

Antithrombotic treatment for acute extracranial carotid artery dissections: a meta-analysis

INTRODUCTION

Carotid artery dissection is a leading cause of stroke in younger patients, with an associated prevalence of 2.6-3.0 per 100,000 population. This meta-analysis aims to determine whether in patients managed medically, treatment with anticoagulants or antiplatelet agents was associated with a better outcome with respect to mortality, ischaemic stroke, and major bleeding episodes.

PATIENTS AND METHODS

A comprehensive search strategy was employed of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (January 1966 to March 2015), and EMBASE (January 1980 to March 2015) databases. Primary outcomes were death (all causes) or disability. Secondary outcomes were ischaemic stroke, symptomatic intracranial haemorrhage, and major extracranial haemorrhage during the reported follow-up period.

RESULTS

No completed randomized trials were found. Comparing antiplatelets with anticoagulants across 38 studies (1,398 patients), there were no significant differences in the odds of death (effects size, ES, -0.007, p = .871), nor in the death and disability comparison or across any secondary outcomes.

CONCLUSION

There were no randomised trials comparing either anticoagulants or antiplatelets with control, thus there is no level 1 evidence to support their routine use for the treatment of carotid artery dissection. Also, there were no randomised trials that directly compared anticoagulants with antiplatelet drugs, and the reported non-randomised studies did not show any evidence of a significant difference between the two.

Consistency and inconsistency in network meta-analysis: concepts and models for multi-arm studies

Meta-analyses that simultaneously compare multiple treatments (usually referred to as network meta-analyses or mixed treatment comparisons) are becoming increasingly common. An important component of a network meta-analysis is an assessment of the extent to which different sources of evidence are compatible, both substantively and statistically. A simple indirect comparison may be confounded if the studies involving one of the treatments of interest are fundamentally different from the studies involving the other treatment of interest. Here, we discuss methods for addressing inconsistency of evidence from comparative studies of different treatments. We define and review basic concepts of heterogeneity and inconsistency, and attempt to introduce a distinction between ‘loop inconsistency’ and ‘design inconsistency’. We then propose that the notion of design-by-treatment interaction provides a useful general framework for investigating inconsistency. In particular, using design-by-treatment interactions successfully addresses complications that arise from the presence of multi-arm trials in an evidence network. We show how the inconsistency model proposed by Lu and Ades is a restricted version of our full design-by-treatment interaction model and that there may be several distinct Lu–Ades models for any particular data set. We introduce novel graphical methods for depicting networks of evidence, clearly depicting multi-arm trials and illustrating where there is potential for inconsistency to arise. We apply various inconsistency models to data from trials of different comparisons among four smoking cessation interventions and show that models seeking to address loop inconsistency alone can run into problems. Copyright © 2012 John Wiley & Sons, Ltd.

Paediatric CT dose: a multicentre audit of subspecialty practice in Australia and New Zealand

OBJECTIVES

To evaluate paediatric CT dosimetry in Australia and New Zealand and calculate size-specific dose estimates (SSDEs) for chest and abdominal examinations.

METHODS

Eight hospitals provided data from 12 CT systems for 1462 CTs in children aged 0-15. Imaging data were recorded for eight examinations: head (trauma, shunt), temporal bone, paranasal sinuses, chest (mass) and chest HRCT (high-resolution CT), and abdomen/pelvis (mass/inflammation). Dose data for cranial examinations were categorised by age and SSDEs by lateral dimension. Diagnostic reference ranges (DRRs) were defined by the 25th and 75th percentiles. Centralised image quality assessment was not undertaken.

RESULTS

DRRs for 201 abdominopelvic SSDEs were: 2.8-4.7, 3.6-11.5, 8.5-15.0, 7.6-15, and 10.6-16.2 for the <15 cm, 15-19 cm, 20-24 cm, 25-29 cm and >30 cm groups, respectively. For 147 chest examinations using these body width categories, SSDE DRRs were 2.0-4.4, 3.3-7.9, 4.0-9.4, 4.5-12, and 6.5-12. Kilovoltage peak (kVp), but not AEC or IR, was associated with SSDE (parameter estimate [standard error]: 0.12 (0.03); p < 0.0001).

CONCLUSIONS

Australian and New Zealand paediatric CT DRRs and abdominal SSDEs are comparable to international data. SSDEs for chest examinations are proposed. Dose variations could be reduced by adjusting kVp.

KEY POINTS

• SSDEs can be calculated for all patients, CT systems, and practices • Kilovoltage peak (kVp) has the greatest association with dose in similar-sized patients • Paediatric DRRs for CT are now available for use internationally.