| 61. |
- Williams, R. D., et al.
(författare)
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Seek COVER: using a disease proxy to rapidly develop and validate a personalized risk calculator for COVID-19 outcomes in an international network
- 2022
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Ingår i: BMC Medical Research Methodology. - : Springer Science and Business Media LLC. - 1471-2288. ; 22:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: We investigated whether we could use influenza data to develop prediction models for COVID-19 to increase the speed at which prediction models can reliably be developed and validated early in a pandemic. We developed COVID-19 Estimated Risk (COVER) scores that quantify a patient’s risk of hospital admission with pneumonia (COVER-H), hospitalization with pneumonia requiring intensive services or death (COVER-I), or fatality (COVER-F) in the 30-days following COVID-19 diagnosis using historical data from patients with influenza or flu-like symptoms and tested this in COVID-19 patients. Methods: We analyzed a federated network of electronic medical records and administrative claims data from 14 data sources and 6 countries containing data collected on or before 4/27/2020. We used a 2-step process to develop 3 scores using historical data from patients with influenza or flu-like symptoms any time prior to 2020. The first step was to create a data-driven model using LASSO regularized logistic regression, the covariates of which were used to develop aggregate covariates for the second step where the COVER scores were developed using a smaller set of features. These 3 COVER scores were then externally validated on patients with 1) influenza or flu-like symptoms and 2) confirmed or suspected COVID-19 diagnosis across 5 databases from South Korea, Spain, and the United States. Outcomes included i) hospitalization with pneumonia, ii) hospitalization with pneumonia requiring intensive services or death, and iii) death in the 30 days after index date. Results: Overall, 44,507 COVID-19 patients were included for model validation. We identified 7 predictors (history of cancer, chronic obstructive pulmonary disease, diabetes, heart disease, hypertension, hyperlipidemia, kidney disease) which combined with age and sex discriminated which patients would experience any of our three outcomes. The models achieved good performance in influenza and COVID-19 cohorts. For COVID-19 the AUC ranges were, COVER-H: 0.69–0.81, COVER-I: 0.73–0.91, and COVER-F: 0.72–0.90. Calibration varied across the validations with some of the COVID-19 validations being less well calibrated than the influenza validations. Conclusions: This research demonstrated the utility of using a proxy disease to develop a prediction model. The 3 COVER models with 9-predictors that were developed using influenza data perform well for COVID-19 patients for predicting hospitalization, intensive services, and fatality. The scores showed good discriminatory performance which transferred well to the COVID-19 population. There was some miscalibration in the COVID-19 validations, which is potentially due to the difference in symptom severity between the two diseases. A possible solution for this is to recalibrate the models in each location before use. © 2022, The Author(s).
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| 62. |
- Ademuyiwa, Adesoji O., et al.
(författare)
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Determinants of morbidity and mortality following emergency abdominal surgery in children in low-income and middle-income countries
- 2016
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Ingår i: BMJ Global Health. - : BMJ Publishing Group Ltd. - 2059-7908. ; 1:4
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Tidskriftsartikel (refereegranskat)abstract
- Background: Child health is a key priority on the global health agenda, yet the provision of essential and emergency surgery in children is patchy in resource-poor regions. This study was aimed to determine the mortality risk for emergency abdominal paediatric surgery in low-income countries globally.Methods: Multicentre, international, prospective, cohort study. Self-selected surgical units performing emergency abdominal surgery submitted prespecified data for consecutive children aged <16 years during a 2-week period between July and December 2014. The United Nation's Human Development Index (HDI) was used to stratify countries. The main outcome measure was 30-day postoperative mortality, analysed by multilevel logistic regression.Results: This study included 1409 patients from 253 centres in 43 countries; 282 children were under 2 years of age. Among them, 265 (18.8%) were from low-HDI, 450 (31.9%) from middle-HDI and 694 (49.3%) from high-HDI countries. The most common operations performed were appendectomy, small bowel resection, pyloromyotomy and correction of intussusception. After adjustment for patient and hospital risk factors, child mortality at 30 days was significantly higher in low-HDI (adjusted OR 7.14 (95% CI 2.52 to 20.23), p<0.001) and middle-HDI (4.42 (1.44 to 13.56), p=0.009) countries compared with high-HDI countries, translating to 40 excess deaths per 1000 procedures performed.Conclusions: Adjusted mortality in children following emergency abdominal surgery may be as high as 7 times greater in low-HDI and middle-HDI countries compared with high-HDI countries. Effective provision of emergency essential surgery should be a key priority for global child health agendas.
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| 63. |
- Alfonzo, Emilia, et al.
(författare)
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No survival difference between robotic and open radical hysterectomy for women with early-stage cervical cancer: results from a nationwide population-based cohort study
- 2019
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Ingår i: European Journal of Cancer. - : Elsevier BV. - 0959-8049 .- 1879-0852. ; 116, s. 169-177
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: The aim of the study was to compare overall survival (OS) and disease-free survival (DFS) after open and robotic radical hysterectomy for early-stage cervical cancer. Patients and methods: This was a nationwide population-based cohort study on all women with cervical cancer stage IA1-IB of squamous, adenocarcinoma or adenosquamous histological subtypes, from January 2011 to December 2017, for whom radical hysterectomy was performed. The Swedish Quality Register of Gynaecologic Cancer was used for identification. To ensure quality and conformity of data and to disclose patients not yet registered, hospital registries were reviewed and validated. Cox and propensity score regression analysis and univariable and multivariable regression analysis were performed in regard to OS and DFS. Results: There were 864 women (236 open and 628 robotic) included in the study. The 5-year OS was 92% and 94% and DFS was 84% and 88% for the open and robotic cohorts, respectively. The recurrence pattern was similar in both groups. Using propensity score analysis and matched cohorts of 232 women in each surgical group, no significant differences were seen in survival: 5-year OS of 92% in both groups (hazard ratio [HR], 1.00; 95% confidence interval [CI], 0.50–2.01) and DFS of 85% vs 84% in the open and robotic cohort, respectively (HR, 1.08; 95% CI, 0.66–1.78). In univariable and multivariable analysis with OS as the end-point, no significant factors were found, and in regard to DFS, tumour size (p < 0.001) and grade 3 (p = 0.02) were found as independent significant risk factors. Conclusion: In a complete nationwide population-based cohort, where radical hysterectomy for early-stage cervical cancer is highly centralised, neither long-term survival nor pattern of recurrence differed significantly between open and robotic surgery. © 2019 The Authors
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| 64. |
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| 65. |
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| 66. |
- Bidleman, TF, et al.
(författare)
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Chiral pesticides as tracers of air-surface exchange
- 1998
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Ingår i: Environmental Pollution. - 0269-7491 .- 1873-6424. ; 102:1, s. 43-49
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Tidskriftsartikel (refereegranskat)abstract
- The enantiomers of chiral pesticides are selectively broken down in soil and water to yield residues and metabolites, which are non-racemic. The distinctive enantiomer signatures of residues are preserved upon volatilization, providing site-specific tracers for air-soil and air-water exchange. Applications of enantiomeric tracers include distinguishing the atmospheric transport of freshly applied pesticides from those which are 'recycled' from lakes, oceans and soil, and investigating biotic vs abiotic degradation pathways. Examples are given of using pesticide enantiomers to follow volatilization from the Great Lakes and arctic waters and as indicators of pesticide emissions from agricultural soils.
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| 67. |
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| 68. |
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| 69. |
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