| 1. |
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
- Sherratt, K., et al.
(author)
-
Predictive performance of multi-model ensemble forecasts of COVID-19 across European nations
- 2023
-
In: eLIFE. - : eLife Sciences Publications Ltd. - 2050-084X. ; 12
-
Journal article (peer-reviewed)abstract
- Methods: We used open-source tools to develop a public European COVID-19 Forecast Hub. We invited groups globally to contribute weekly forecasts for COVID-19 cases and deaths reported by a standardised source for 32 countries over the next 1–4 weeks. Teams submitted forecasts from March 2021 using standardised quantiles of the predictive distribution. Each week we created an ensemble forecast, where each predictive quantile was calculated as the equally-weighted average (initially the mean and then from 26th July the median) of all individual models’ predictive quantiles. We measured the performance of each model using the relative Weighted Interval Score (WIS), comparing models’ forecast accuracy relative to all other models. We retrospectively explored alternative methods for ensemble forecasts, including weighted averages based on models’ past predictive performance.Results: Over 52 weeks, we collected forecasts from 48 unique models. We evaluated 29 models’ forecast scores in comparison to the ensemble model. We found a weekly ensemble had a consistently strong performance across countries over time. Across all horizons and locations, the ensemble performed better on relative WIS than 83% of participating models’ forecasts of incident cases (with a total N=886 predictions from 23 unique models), and 91% of participating models’ forecasts of deaths (N=763 predictions from 20 models). Across a 1–4 week time horizon, ensemble performance declined with longer forecast periods when forecasting cases, but remained stable over 4 weeks for incident death forecasts. In every forecast across 32 countries, the ensemble outperformed most contributing models when forecasting either cases or deaths, frequently outperforming all of its individual component models. Among several choices of ensemble methods we found that the most influential and best choice was to use a median average of models instead of using the mean, regardless of methods of weighting component forecast models.Conclusions: Our results support the use of combining forecasts from individual models into an ensemble in order to improve predictive performance across epidemiological targets and populations during infectious disease epidemics. Our findings further suggest that median ensemble methods yield better predictive performance more than ones based on means. Our findings also highlight that forecast consumers should place more weight on incident death forecasts than incident case forecasts at forecast horizons greater than 2 weeks.
|
|
| 5. |
- Mylrea-Foley, Bronacha, et al.
(author)
-
Longitudinal Doppler Assessments in Late Preterm Fetal Growth Restriction
- 2023
-
In: Ultraschall in der Medizin. - : Georg Thieme Verlag KG. - 0172-4614. ; 44:1, s. 56-67
-
Journal article (peer-reviewed)abstract
- Purpose To assess the longitudinal variation of the ratio of umbilical and cerebral artery pulsatility index (UCR) in late preterm fetal growth restriction (FGR). Materials and Methods A prospective European multicenter observational study included women with a singleton pregnancy, 32 +0-36 +6, at risk of FGR (estimated fetal weight [EFW] or abdominal circumference [AC] <10 th percentile, abnormal arterial Doppler or fall in AC from 20-week scan of >40 percentile points). The primary outcome was a composite of abnormal condition at birth or major neonatal morbidity. UCR was categorized as normal (<0.9) or abnormal (≥0.9). UCR was assessed by gestational age at measurement interval to delivery, and by individual linear regression coefficient in women with two or more measurements. Results 856 women had 2770 measurements; 696 (81%) had more than one measurement (median 3 (IQR 2-4). At inclusion, 63 (7%) a UCR ≥0.9. These delivered earlier and had a lower birth weight and higher incidence of adverse outcome (30% vs. 9%, relative risk 3.2; 95%CI 2.1-5.0) than women with a normal UCR at inclusion. Repeated measurements after an abnormal UCR at inclusion were abnormal again in 67% (95%CI 55-80), but after a normal UCR the chance of finding an abnormal UCR was 6% (95%CI 5-7%). The risk of composite adverse outcome was similar using the first or subsequent UCR values. Conclusion An abnormal UCR is likely to be abnormal again at a later measurement, while after a normal UCR the chance of an abnormal UCR is 5-7% when repeated weekly. Repeated measurements do not predict outcome better than the first measurement, most likely due to the most compromised fetuses being delivered after an abnormal UCR.
|
|
| 6. |
- Stampalija, T., et al.
(author)
-
Fetal cerebral Doppler changes and outcome in late preterm fetal growth restriction : prospective cohort study
- 2020
-
In: Ultrasound in Obstetrics and Gynecology. - : Wiley. - 0960-7692 .- 1469-0705. ; 56:2, s. 173-181
-
Journal article (peer-reviewed)abstract
- Objectives To explore the association between fetal umbilical and middle cerebral artery (MCA) Doppler abnormalities and outcome in late preterm pregnancies at risk of fetal growth restriction. Methods This was a prospective cohort study of singleton pregnancies at risk of fetal growth restriction at 32+ 0 to 36+ 6weeks of gestation, enrolled in 33 European centers between 2017 and 2018, in which umbilical and fetal MCA Doppler velocimetry was performed. Pregnancies were considered at risk of fetal growth restriction if they had estimated fetal weight and/or abdominal circumference (AC) < 10th percentile, abnormal arterial Doppler and/or a fall in AC growth velocity of more than 40 percentile points from the 20-week scan. Composite adverse outcome comprised both immediate adverse birth outcome and major neonatal morbidity. Using a range of cut-off values, the association of MCA pulsatility index and umbilicocerebral ratio (UCR) with composite adverse outcome was explored. Results The study population comprised 856 women. There were two (0.2%) intrauterine deaths. Median gestational age at delivery was 38 (interquartile range (IQR), 37-39) weeks and birth weight was 2478 (IQR, 2140-2790) g. Compared with infants with normal outcome, those with composite adverse outcome (n= 93; 11%) were delivered at an earlier gestational age (36 vs 38 weeks) and had a lower birth weight (1900 vs 2540 g). The first Doppler observation of MCA pulsatility index < 5th percentile and UCR Z-score above gestational-age-specific thresholds (1.5 at 32-33weeks and 1.0 at 34-36weeks) had the highest relative risks (RR) for composite adverse outcome (RR 2.2 (95% CI, 1.5-3.2) and RR 2.0 (95% CI, 1.4-3.0), respectively). After adjustment for confounders, the association between UCR Z-score and composite adverse outcome remained significant, although gestational age at delivery and birth-weight Z-score had a stronger association. Conclusion In this prospective multicenter study, signs of cerebral blood flow redistribution were found to be associated with adverse outcome in late preterm singleton pregnancies at risk of fetal growth restriction. Whether cerebral redistribution is a marker describing the severity of fetal growth restriction or an independent risk factor for adverse outcome remains unclear, and whether it is useful for clinical management can be answered only in a randomized trial. (C) 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
|
|
| 11. |
|
|
| 12. |
|
|
| 13. |
|
|
| 14. |
|
|
| 15. |
- Griffiths, P, et al.
(author)
-
Nurse staffing, nursing assistants and hospital mortality: retrospective longitudinal cohort study
- 2019
-
In: BMJ quality & safety. - : BMJ. - 2044-5423 .- 2044-5415. ; 28:8, s. 609-617
-
Journal article (peer-reviewed)abstract
- To determine the association between daily levels of registered nurse (RN) and nursing assistant staffing and hospital mortality.DesignThis is a retrospective longitudinal observational study using routinely collected data. We used multilevel/hierarchical mixed-effects regression models to explore the association between patient outcomes and daily variation in RN and nursing assistant staffing, measured as hours per patient per day relative to ward mean. Analyses were controlled for ward and patient risk.Participants138 133 adult patients spending >1 days on general wards between 1 April 2012 and 31 March 2015.OutcomesIn-hospital deaths.ResultsHospital mortality was 4.1%. The hazard of death was increased by 3% for every day a patient experienced RN staffing below ward mean (adjusted HR (aHR) 1.03, 95% CI 1.01 to 1.05). Relative to ward mean, each additional hour of RN care available over the first 5 days of a patient’s stay was associated with 3% reduction in the hazard of death (aHR 0.97, 95% CI 0.94 to 1.0). Days where admissions per RN exceeded 125% of the ward mean were associated with an increased hazard of death (aHR 1.05, 95% CI 1.01 1.09). Although low nursing assistant staffing was associated with increases in mortality, high nursing assistant staffing was also associated with increased mortality.ConclusionLower RN staffing and higher levels of admissions per RN are associated with increased risk of death during an admission to hospital. These findings highlight the possible consequences of reduced nurse staffing and do not give support to policies that encourage the use of nursing assistants to compensate for shortages of RNs.
|
|
