Dacron® vs. PTFE as bypass materials in peripheral vascular surgery – systematic review and meta-analysis

Roll S, Müller-Nordhorn J, Keil T, et al. Dacron® vs. PTFE as bypass materials in peripheral vascular surgery – systematic review and meta-analysis. BMC Surgery. 2008;8(1): 22.Background: In peripheral vascular bypass surgery different synthetic materials are available for bypass grafting. It is unclear which of the two commonly used materials, polytetrafluoroethylene (PTFE) or polyester (Dacron®) grafts, is to be preferred. Thus, the aim of this meta-analysis and systematic review was to compare the effectiveness of these two prosthetic bypass materials (Dacron® and PTFE). Methods: We performed a systematic literature search in MEDLINE, Cochrane-Library – CENTRAL, EMBASE and other databases for relevant publications in English and German published between 1999 and 2008. Only randomized controlled trials were considered for inclusion. We assessed the methodological quality by means of standardized checklists. Primary patency was used as the main endpoint. Random-effect meta-analysis as well as pooling data in life table format was performed to combine study results. Results: Nine randomized controlled trials (RCT) were included. Two trials showed statistically significant differences in primary patency, one favouring Dacron® and one favouring PTFE grafts, while 7 trials did not show statistically significant differences between the two materials. Meta-analysis on the comparison of PTFE vs. Dacron® grafts yielded no differences with regard to primary patency rates (hazard ratio 1.04 (95% confidence interval [0.85;1.28]), no significant heterogeneity (p = 0.32, I2 = 14%)). Similarly, there were no significant differences with regard to secondary patency rates. Conclusion: Systematic evaluation and meta-analysis of randomized controlled trials comparing Dacron® and PTFE as bypass materials for peripheral vascular surgery showed no evidence of an advantage of one synthetic material over the other

Modeling infectious disease dynamics in the complex landscape of global health.

Despite some notable successes in the control of infectious diseases, transmissible pathogens still pose an enormous threat to human and animal health. The ecological and evolutionary dynamics of infections play out on a wide range of interconnected temporal, organizational, and spatial scales, which span hours to months, cells to ecosystems, and local to global spread. Moreover, some pathogens are directly transmitted between individuals of a single species, whereas others circulate among multiple hosts, need arthropod vectors, or can survive in environmental reservoirs. Many factors, including increasing antimicrobial resistance, increased human connectivity and changeable human behavior, elevate prevention and control from matters of national policy to international challenge. In the face of this complexity, mathematical models offer valuable tools for synthesizing information to understand epidemiological patterns, and for developing quantitative evidence for decision-making in global health

Development and validation of a patient-reported questionnaire assessing systemic therapy induced diarrhea in oncology patients

Abstract Background Systemic therapy-induced diarrhea (STID) is a common side effect experienced by more than half of cancer patients. Despite STID-associated complications and poorer quality of life (QoL), no validated assessment tools exist to accurately assess STID occurrence and severity to guide clinical management. Therefore, we developed and validated a patient-reported questionnaire (STIDAT). Methods The STIDAT was developed using the FDA iterative process for patient-reported outcomes. A literature search uncovered potential items and questions for questionnaire construction used by oncology clinicians to develop questions for the preliminary instrument. The instrument was evaluated on its face validity and content validity by patient interviews. Repetitive, similar and different themes uncovered from patient interviews were implemented to revise the instrument to the version used for validation. Patients starting high-risk STID treatments were monitored using the STIDAT, bowel diaries and EORTC QLQ-C30. The STIDAT was evaluated for construct validity using exploratory factor analysis (EFA) using minimal residual method with Promax rotation, reliability and consistency. A weighted scoring system was developed and a receiver-operating characteristic (ROC) curve evaluated the tool’s ability to detect STID occurrence. Median scores and variability were analysed to determine how well it differentiates between diarrhea severities. A post-hoc analysis determined how diarrhea severity impacted QoL of cancer patients. Results Patients defined diarrhea based on presence of watery stool. The STIDAT assessed patient’s perception of having diarrhea, daily number of bowel movements, daily number of diarrhea episodes, antidiarrheal medication use, the presence of urgency, abdominal pain, abdominal spasms or fecal incontinence, patient’s perception of diarrhea severity, and QoL. These dimensions were sorted into four clusters using EFA – patient’s perception of diarrhea, frequency of diarrhea, fecal incontinence and abdominal symptoms. Cronbach’s alpha was 0.78; kappa ranged from 0.934–0.952, except for abdominal spasms (κ = 0.0455). The positive predictive value was 96.4%, with the minimum score of 1.35 predicting a positive STID occurrence. Patients with moderate or severe diarrhea experience significant decreases in QoL compared to those with no diarrhea. Conclusions This is the first patient-reported questionnaire that accurately predicts the occurrence and severity of diarrhea in oncology patients via assessing several bowel habit dimensions

Incidence estimation using a single cross-sectional age-specific prevalence survey with differential mortality.

Here, we present a method for incidence estimation of a curable, non-recurring disease when data from a single cross-sectional survey are used together with population-level mortality rates and an assumption of differential mortality of diseased versus non-diseased individuals. The motivating example is cataract, and the VISION2020 goal to eliminate avoidable blindness globally by 2020. Reliable estimates of current and future cataract disease burden are required to predict how many surgeries would need to be performed to meet the VISION2020 goals. However, incidence estimates, needed to derive future burden, are not as easily available, due to the cost of conducting cohort studies. Disease is defined at the person-level in accordance with the WHO person-level definition of blindness. An extension of the standard time homogeneous illness-death model to a four-state model is described, which allows the disease to be cured, whereby surgery is performed on at least one diseased eye. Incidence is estimated, and the four-state model is used to predict disease burden assuming different surgical strategies whilst accounting for the competing risk of death. The method is applied to data from approximately 10,000 people from a survey of visual impairment in Nigeria

Cost-effectiveness of interferon ? or peginterferon ?, with ribavirin for histologically mild chronic hepatitis C

Background: For patients with mild chronic hepatitis C the cost-effectiveness of antiviral therapy is unknown.Aims: To assess whether anti-viral therapy (either interferon α or peginterferon α combined with ribavirin) is cost-effective at a mild stage compared to waiting and only treating those cases who progress to moderate disease.Patients: Cases with mild chronic hepatitis C.Methods: A cost-effectiveness model estimates long-term costs and outcomes for patients with mild chronic hepatitis C. The model uses effectiveness and cost data from the UK mild hepatitis C RCT, combined with estimates of disease progression and cost from observational studies.Results: Antiviral treatment at a mild rather than a moderate stage improved outcomes measured by Quality Adjusted Life Years (QALYs) gained. The mean cost per QALY gained from antiviral treatment with interferon α-2b and ribavirin, compared to no treatment at a mild stage, was £4,535 ($7,108) for patients with genotype non-1 and £25,188 ($39,480) for patients with genotype 1. Providing peginterferon α-2b and ribavirin at a mild rather than a moderate stage was also associated with a gain in QALYs; the costs per QALY gained were £7,821 ($12,259) for patients with genotype non-1 and £28,409 ($44,528) for patients with genotype 1.Conclusions: For patients with chronic hepatitis C, it is generally more cost-effective to provide antiviral treatment at a mild rather than a moderate disease stage. For older patients (aged 65 or over) with genotype 1, antiviral treatment at a mild stage is not cost-effective

Significantly lower infection fatality rates associated with SARS-CoV-2 Omicron (B.1.1.529) infection in children and young people: Active, prospective national surveillance, January-March 2022, England.

Funder: UK Health Security Agenc

Risk of paediatric multisystem inflammatory syndrome (PIMS-TS) during the SARS-CoV-2 alpha and delta variant waves: National observational and modelling study, 2020-21, England.

Peer reviewed: TrueOBJECTIVES: Paediatric Multisystem Inflammatory Syndrome (PIMS-TS) is a rare life-threatening complication that typically occurs several weeks after SARS-CoV-2 infection in children and young people (CYP). We used national and regional-level data from the COVID-19 pandemic waves in England to develop a model to predict PIMS-TS cases. METHODS: SARS-CoV-2 infections in CYP aged 0-15 years in England were estimated using the PHE-Cambridge real-time model. PIMS-TS cases were identified through the British Paediatric Surveillance Unit during (March-June 2020) and through Secondary Uses Services (SUS) from November 2020. A predictive model was developed to estimate PIMS-TS risk and lag times after SARS-CoV-2 infections. RESULTS: During the Alpha wave, the model accurately predicted PIMS-TS cases (506 vs. 502 observed cases), with a median estimated risk of 0.038% (IQR, 0.037-0.041%) of paediatric SARS-CoV-2 infections. For the Delta wave, the median risk of PIMS-TS was significantly lower at 0.026% (IQR, 0.025-0.029%), with 212 observed PIMS-TS cases compared to 450 predicted by the model. CONCLUSIONS: The model accurately predicted national and regional PIMS-TS cases in CYP during the Alpha wave. PIMS-TS cases were 53% lower than predicted during the Delta wave. Further studies are needed to understand the mechanisms of the observed lower risk with the Delta variant

Datasheet1_Risk of paediatric multisystem inflammatory syndrome (PIMS-TS) during the SARS-CoV-2 alpha and delta variant waves: National observational and modelling study, 2020–21, England.pdf

ObjectivesPaediatric Multisystem Inflammatory Syndrome (PIMS-TS) is a rare life-threatening complication that typically occurs several weeks after SARS-CoV-2 infection in children and young people (CYP). We used national and regional-level data from the COVID-19 pandemic waves in England to develop a model to predict PIMS-TS cases.MethodsSARS-CoV-2 infections in CYP aged 0–15 years in England were estimated using the PHE-Cambridge real-time model. PIMS-TS cases were identified through the British Paediatric Surveillance Unit during (March-June 2020) and through Secondary Uses Services (SUS) from November 2020. A predictive model was developed to estimate PIMS-TS risk and lag times after SARS-CoV-2 infections.ResultsDuring the Alpha wave, the model accurately predicted PIMS-TS cases (506 vs. 502 observed cases), with a median estimated risk of 0.038% (IQR, 0.037–0.041%) of paediatric SARS-CoV-2 infections. For the Delta wave, the median risk of PIMS-TS was significantly lower at 0.026% (IQR, 0.025–0.029%), with 212 observed PIMS-TS cases compared to 450 predicted by the model.ConclusionsThe model accurately predicted national and regional PIMS-TS cases in CYP during the Alpha wave. PIMS-TS cases were 53% lower than predicted during the Delta wave. Further studies are needed to understand the mechanisms of the observed lower risk with the Delta variant.</p