403 research outputs found
Survival prediction in mesothelioma using a scalable lasso regression model: instructions for use and initial performance using clinical predictors
Introduction: Accurate prognostication is difficult in malignant pleural mesothelioma (MPM). We developed a set of robust computational models to quantify the prognostic value of routinely available clinical data, which form the basis of published MPM prognostic models.
Methods: Data regarding 269 patients with MPM were allocated to balanced training (n=169) and validation sets (n=100). Prognostic signatures (minimal length best performing multivariate trained models) were generated by least absolute shrinkage and selection operator regression for overall survival (OS), OS <6 months and OS <12 months. OS prediction was quantified using Somers DXY statistic, which varies from 0 to 1, with increasing concordance between observed and predicted outcomes. 6-month survival and 12-month survival were described by area under the curve (AUC) scores.
Results: Median OS was 270 (IQR 140–450) days. The primary OS model assigned high weights to four predictors: age, performance status, white cell count and serum albumin, and after cross-validation performed significantly better than would be expected by chance (mean DXY0.332 (±0.019)). However, validation set DXY was only 0.221 (0.0935–0.346), equating to a 22% improvement in survival prediction than would be expected by chance. The 6-month and 12-month OS signatures included the same four predictors, in addition to epithelioid histology plus platelets and epithelioid histology plus C-reactive protein (mean AUC 0.758 (±0.022) and 0.737 (±0.012), respectively). The <6-month OS model demonstrated 74% sensitivity and 68% specificity. The <12-month OS model demonstrated 63% sensitivity and 79% specificity. Model content and performance were generally comparable with previous studies.
Conclusions: The prognostic value of the basic clinical information contained in these, and previously published models, is fundamentally of limited value in accurately predicting MPM prognosis. The methods described are suitable for expansion using emerging predictors, including tumour genomics and volumetric staging
Tropical cyclone perceptions, impacts and adaptation in the Southwest Pacific: an urban perspective from Fiji, Vanuatu and Tonga
The destruction caused by tropical cyclone (TC) Pam in March 2015 is considered one of the worst natural disasters in the history of Vanuatu. It has highlighted the need for a better understanding of TC impacts and adaptation in the Southwest Pacific (SWP) region. Therefore, the key aims of this study are to (i) understand local perceptions of TC activity, (ii) investigate impacts of TC activity and (iii) uncover adaptation strategies used to offset the impacts of TCs. To address these aims, a survey (with 130 participants from urban areas) was conducted across three SWP small island states (SISs): Fiji, Vanuatu and Tonga (FVT). It was found that respondents generally had a high level of risk perception and awareness of TCs and the associated physical impacts, but lacked an understanding of the underlying weather conditions. Responses highlighted that current methods of adaptation generally occur at the local level, immediately prior to a TC event (preparation of property, gathering of food, finding a safe place to shelter). However higher level adaptation measures (such as the modification to building structures) may reduce vulnerability further. Finally, we discuss the potential of utilising weather-related traditional knowledge and non-traditional knowledge of empirical and climate-model-based weather forecasts to improve TC outlooks, which would ultimately reduce vulnerability and increase adaptive capacity. Importantly, lessons learned from this study may result in the modification and/or development of existing adaptation strategies
Electrochemical Characterization of Self-Assembled Monolayers on Gold Substrates Derived from Thermal Decomposition of Monolayer-Protected Cluster Films
Networked films of monolayer-protected clusters (MPCs), alkanethiolate-stabilized gold nanoparticles, can be thermally decomposed to form stable gold on glass substrates that are subsequently modified with self-assembled monolayers (SAMs) for use as modified electrodes. Electrochemical assessment of these SAM-modified gold substrates, including double-layer capacitance measurements, linear sweep desorption of the alkanethiolates, and diffusional redox probing, all show that SAMs formed on gold supports formed from thermolysis of MPC films possess substantially higher defect density compared to SAMs formed on traditional evaporated gold. The density of defects in the SAMs on thermolyzed gold is directly related to the strategies used to assemble the MPC film prior to thermolysis. Specifically, gold substrates formed from thermally decomposing MPC films formed with electrostatic bridges between carboxylic acid-modified MPCs and metal ion linkers are particularly sensitive to the degree of metal exposure during the assembly process. While specific metal dependence was observed, metal concentration within the MPC precursor film was determined to be a more significant factor. Specific MPC film linking strategies and pretreatment methods that emphasized lower metal exposure resulted in gold films that supported SAMs of lower defect density. The defect density of a SAM-modified electrode is shown to be critical in certain electrochemical experiments such as protein monolayer electrochemistry of adsorbed cytochrome c. While the thermal decomposition of nanoparticle film assemblies remains a viable and interesting technique for coating both flat and irregular shaped substrates, this study provides electrochemical assessment tools and tactics for determining and controlling SAM defect density on this type of gold structure, a property critical to their effective use in subsequent electrochemical applications
Doctors are inconsistent in estimating survival after CPR and are not using such predictions consistently in determining DNACPR decisions
Background: It is unclear whether doctors base their resuscitation decisions solely on their perceived outcome. Through the use of theoretical scenarios, we aimed to examine the ‘do not attempt cardiopulmonary resuscitation’ (DNACPR) decision-making. Methods: A questionnaire survey was sent to consultants and specialty trainees across two Norfolk (UK) hospitals during December 2013. The survey included demographic questions and six clinical scenarios with varying prognosis. Participants were asked if they would resuscitate the patient or not. Identical scenarios were then shown in a different order and doctors were asked to quantify patients’ estimated chance of survival. Results: A total of 137 individuals (mean age 41 years (SD 7.9%)) responded. The response rate was 69%. Approximately 60% were consultants. We found considerable variation in clinician estimates of median chance of survival. In three out of six of our scenarios, the survival estimated varied from <1% to 95%. There was a statistically significant difference identified in the estimated median survival between those clinicians who would or would not resuscitate in four of the six scenarios presented. Conclusion: This study has highlighted the wide variation between clinicians in their estimates of likely survival and little concordance between clinicians over their resuscitation decisions. The diversity in clinician decision-making should be explored further
Population-level susceptibility, severity and spread of pandemic influenza: design of, and initial results from, a pre-pandemic and hibernating pandemic phase study using cross-sectional data from the Health Survey for England (HSE)
Background
Assessing severity and spread of a novel influenza strain at the start of a pandemic is critical for informing a targeted and proportional response. It requires community-level studies to estimate the burden of infection and disease. Rapidly initiating such studies in a pandemic is difficult. The study aims to establish an efficient system allowing real-time assessment of population susceptibility, spread of infection and clinical attack rates in the event of a pandemic.
Methods
We developed and appended additional survey questions and specimen collection to the Health Survey for England (HSE) – a large, annual, rolling nationally representative general population survey recruiting throughout the year – to enable rapid population-based surveys of influenza infection and disease during a pandemic. Using these surveys we can assess the spread of the virus geographically, by age and through time. The data generated can also provide denominators for national estimates of case fatality and hospitalisation rates.Phase 1: we compared retrospectively collected HSE illness rates during the first two infection waves of the 2009 pandemic with the Flu Watch study (a prospective community cohort). Monthly and seasonal age-specific rates of illness and proportion vaccinated were compared.Phase 2: we piloted blood specimen and data collection alongside the 2012–13 HSE. We are developing laboratory methods and protocols for real-time serological assays of a novel pandemic influenza virus using these specimens, and automated programmes for analysing and reporting illness and infection rates.Phase 3: during inter-pandemic years, the study enters a holding phase, where it is included in the yearly HSE ethics application and planning procedures, allowing rapid triggering in a pandemic.Phase 4: once retriggered, the study will utilise the methods developed in phase 2 to monitor the severity and spread of the pandemic in real time.
Results
Phase 1: the rates of reported illness during the first two waves in the HSE underestimated the community burden as measured by Flu Watch, but the patterns of illness by age and time were broadly comparable. The extent of underestimation was greatest for HSE participants interviewed later in the year compared with those interviewed closer to the pandemic. Vaccine uptake in the HSE study was comparable to independent national estimates and the Flu Watch study.Phases 2 and 3: illness data and serological samples from 2018 participants were collected in the 2012–13 HSE and transferred to the University College London Hospital. In the 2013 HSE and onwards, this project was included in the annual HSE ethics and planning rounds.
Conclusions
The HSE’s underestimation of illness rates during the first two waves of the pandemic is probably due to recall bias and the limitation of being able to report only one illness when multiple illnesses per season can occur. Changes to the illness questions (reporting only recent illnesses) should help minimise these issues. Additional prospective follow-up could improve measurement of disease incidence. The representative nature of the HSE allows accurate measurements of vaccine uptake.
Study registration
This study is registered as ISRCTN80214280.
Funding
This project was funded by the NIHR Public Health Research programme and will be published in full inPublic Health Research; Vol. 3, No. 6. See the NIHR Journals Library website for further project information
Pre-EDIT: protocol for a randomised feasibility trial of elastance-directed intrapleural catheter or talc pleurodesis (EDIT) in malignant pleural effusion
Introduction: Non-expansile lung (NEL) is a common cause of talc pleurodesis (TP) failure in malignant pleural effusion (MPE), but is often occult prior to drainage. Reliable detection of NEL would allow patients to be allocated between intrapleural catheter (IPC) and TP. High pleural elastance (PEL) has been associated with NEL in observational studies. Pre-EDIT is a randomised feasibility trial of elastance-directed IPC or TP (EDIT) management using a novel, purpose-built digital pleural manometer (Rocket Medical, UK).
Methods and analysis: Consecutive patients with MPE without prior evidence of NEL or preference for IPC will be randomised 1:1 between EDIT management and standard care (an attempt at TP). The primary objective is to determine whether sufficient numbers of patients (defined as 30 within 12 months (or 15 over 6 months)) can be recruited and randomised to justify a subsequent phase III trial testing the efficacy of EDIT management. Secondary objectives include safety, technical feasibility and validation of study design elements, including the definition of PEL using 4D pleural MRI before and after fluid aspiration. EDIT involves PEL assessment during a large volume pleural fluid aspiration, followed by an attempt at TP or placement of an IPC within 24 hours. Patients will be allocated to IPC if the rolling average PEL sustained over at least 250 mL fluid aspirated (PEL250) is ≥ 14.5 cm H2O/L.
Ethics and dissemination: Pre-EDIT was approved by the West of Scotland Regional Ethics Committee on 8 March 2017 (Ref: 17/WS/0042). Results will be presented at scientific meetings and published in peer-reviewed journals
Chest drain aerosol generation in COVID-19 and emission reduction using a simple anti-viral filter
Introduction: The COVID-19 pandemic has been characterised by significant in-hospital virus transmission and deaths among healthcare workers. Sources of in-hospital transmission are not fully understood, with special precautions currently reserved for procedures previously shown to generate aerosols (particles <5 μm). Pleural procedures are not currently considered AGPs (Aerosol Generating Procedures), reflecting a lack of data in this area.
Methods: An underwater seal chest drain bottle (R54500, Rocket Medical UK) was set up inside a 60-litre plastic box and connected via an airtight conduit to a medical air supply. A multichannel particle counter (TSI Aerotrak 9310 Aerosol Monitor) was placed inside the box, allowing measurement of particle count/cubic foot (pc/ft3) within six channel sizes: 0.3–0.5, 0.5–1, 1–3, 3–5, 5–10 and >10 μm. Stabilised particle counts at 1, 3 and 5 L/min were compared by Wilcoxon signed rank test; p values were Bonferroni-adjusted. Measurements were repeated with a simple anti-viral filter, designed using repurposed materials by the study team, attached to the drain bottle. The pressure within the bottle was measured to assess any effect of the filter on bottle function.
Results: Aerosol emissions increased with increasing air flow, with the largest increase observed in smaller particles (0.3–3 μm). Concentration of the smallest particles (0.3–0.5 μm) increased from background levels by 700, 1400 and 2500 pc/ft3 at 1, 3 and 5 L/min, respectively. However, dispersion of particles of all sizes was effectively prevented by use of the viral filter at all flow rates. Use of the filter was associated with a maximum pressure rise of 0.3 cm H2O after 24 hours of flow at 5 L/min, suggesting minimal impact on drain function.
Conclusion: A bubbling chest drain is a source of aerosolised particles, but emission can be prevented using a simple anti-viral filter. These data should be considered when designing measures to reduce in-hospital spread of SARS-CoV-2
A Multi-Institutional Analysis of Adjuvant Chemotherapy and Radiation Sequence in Women With Stage IIIC Endometrial Cancer
PURPOSE: Our purpose was to evaluate the effect of sequence and type of adjuvant therapy for patients with stage IIIC endometrial carcinoma (EC) on outcomes.
METHODS AND MATERIALS: In a multi-institutional retrospective cohort study, patients with stage IIIC EC who had surgical staging and received both adjuvant chemotherapy and radiation therapy (RT) were included. Adjuvant treatment regimens were classified as adjuvant chemotherapy followed by sequential RT (upfront chemo), which was predominant sequence; RT with concurrent chemotherapy followed by chemotherapy (concurrent); systemic chemotherapy before and after RT (sandwich); adjuvant RT followed by chemotherapy (upfront RT); or chemotherapy concurrent with vaginal cuff brachytherapy alone (chemo-brachy). Overall survival (OS) and recurrence-free survival (RFS) rates were estimated by the Kaplan-Meier method.
RESULTS: A total of 686 eligible patients were included with a median follow-up of 45.3 months. The estimated 5-year OS and RFS rates were 74% and 66%, respectively. The sequence and type of adjuvant therapy were not correlated with OS or RFS (adjusted P = .68 and .84, respectively). On multivariate analysis, black race, nonendometrioid histology, grade 3 tumor, stage IIIC2, and presence of adnexal and cervical involvement were associated with worse OS and RFS (all P \u3c .05). Regardless of the sequence of treatment, the most common site of first recurrence was distant metastasis (20.1%). Vaginal only, pelvic only, and paraortic lymph node (PALN) recurrences occurred in 11 (1.6%),15 (2.2 %), and 43 (6.3 %) patients, respectively. Brachytherapy alone was associated with a higher rate of PALN recurrence (15%) compared with external beam radiation therapy (5%) P \u3c .0001.
CONCLUSIONS: The sequence and type of combined adjuvant therapy did not affect OS or RFS rates. Brachytherapy alone was associated with a higher rate of PALN recurrence, emphasizing the role of nodal radiation for stage IIIC EC. The vast proportion of recurrences were distant despite systemic chemotherapy, highlighting the need for novel regimens
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