Category: Statistics

J Contam Hydrol. 2021 Sep 3;243:103887. doi: 10.1016/j.jconhyd.2021.103887. Online ahead of print.

ABSTRACT

Future changes in drought events are critical for risk assessment and associated policymaking. In this study, the future changes in meteorological droughts in Henan Province, China are explored. Random forests downscaling model is first constructed based on ERA5 reanalysis data and meteorological observations. The model is validated using evaluation indices such as R² and RMSE, and is shown to be able to capture the relationship between large-scale predictors and monthly precipitation. The validated random forests downscaling model is driven by multiple global climate models (GCMs) from the Phase 6 of the Coupled Model Intercomparison Project (CMIP6) under three emission scenarios for projecting three future drought characteristics (duration, frequency, and intensity). Results show that drought frequency decreases in most areas of Henan while drought duration and intensity increase in various degrees. Some differences are also observed among different emission scenarios, especially under SSP2-4.5, where the magnitudes of changes in drought duration and intensity are lower relative to other scenarios. The decrease in drought frequency in most areas is found to be caused by increases in monthly mean precipitation in this study. Changes in drought duration and intensity are related to a combination of increases in precipitation mean and variability.

PMID:34500145 | DOI:10.1016/j.jconhyd.2021.103887

J Vet Emerg Crit Care (San Antonio). 2021 Sep 9. doi: 10.1111/vec.13138. Online ahead of print.

ABSTRACT

OBJECTIVE: To report the rate of fluid production at the time of removal of thoracostomy tubes placed intraoperatively and to determine the association of this rate with specific patient factors, surgical factors, or clinical diagnosis. The secondary objective was to determine whether identification of pleural effusion within 2 weeks of thoracostomy tube removal was associated with the same variables.

DESIGN: Retrospective study.

SETTING: University teaching hospital.

ANIMALS: One hundred eighty-five client-owned dogs with thoracostomy tubes placed intraoperatively between January 2010 and March 2017.

INTERVENTIONS: None.

MEASUREMENTS AND MAIN RESULTS: Thoracostomy tubes were removed at a median fluid production of 0.09 mL/kg/h (range, 0-7.0 m L/kg/h). Median fluid production at the time of thoracostomy tube removal was significantly higher in dogs with preoperative pleural effusion compared to dogs without preoperative pleural effusion (0.21 vs 0.05 mL/kg/h; P = 0.0001) and in dogs that had a median sternotomy compared to dogs that had a lateral thoracotomy (0.14 vs 0.09 mL/kg/h; P = 0.04). Of the 169 dogs available for follow-up, 12 (7.1%) had pleural effusion within 2 weeks of removal of the thoracostomy tube. Detection of pleural effusion during the follow-up period was significantly associated with the presence of preoperative pleural effusion (P = 0.0019) and the diagnosis (P = 0.01). A greater proportion of dogs with a lung lobe torsion (4/9, 44.4%) and idiopathic chylothorax (2/7, 28.5%) had pleural effusion within 2 weeks compared to other diagnoses. Reintervention was performed in 4.7% of dogs.

CONCLUSIONS: Thoracostomy tubes were removed at pleural fluid production rates that frequently exceeded current veterinary guidelines. However, the fluid production rate at the time of thoracostomy tube removal was not associated with the detection of pleural effusion within 2 weeks of thoracostomy tube removal, and the overall need for reintervention following thoracostomy tube removal was low (4.7%).

PMID:34499801 | DOI:10.1111/vec.13138

Environ Microbiol. 2021 Sep 9. doi: 10.1111/1462-2920.15765. Online ahead of print.

ABSTRACT

Global warming affects the aquatic ecosystems, accelerating pathogenic microorganisms’ and toxic microalgae’s growth and spread in marine habitats, and in bivalve molluscs. New parasite invasions are directly linked to oceanic warming. Consumption of pathogen-infected molluscs impacts human health at different rates, depending, inter alia, on the bacteria taxa. It is therefore necessary to monitor microbiological and chemical contamination of food. Many global cases of poisoning from bivalve consumption can be traced back to Mediterranean regions. This paper’s aim is to examine the marine bivalve’s infestation rate within the scope of climate change, as well as to evaluate the risk posed by climate change to bivalve welfare and public health. Biological and climatic data literature review was performed from international scientific sources, Greek authorities and State organizations. Focusing on Greek aquaculture and bivalve fisheries, high risk index pathogenic parasites and microalgae were observed during summer months, particularly in Thermaikos Gulf. Considering the climate models that predict further temperature increases, it seems that marine organisms will be subjected in the long-term to higher temperatures. Due to the positive linkage between temperature and microbial load, the marine areas most affected by this phenomenon are characterized as “high risk” for consumer health. This article is protected by copyright. All rights reserved.

PMID:34499795 | DOI:10.1111/1462-2920.15765

J Vet Emerg Crit Care (San Antonio). 2021 Sep 9. doi: 10.1111/vec.13135. Online ahead of print.

ABSTRACT

OBJECTIVE: To develop a population-derived, parsimonious, and objective risk stratification model for dogs following trauma and compare its predictive performance to the animal trauma triage (ATT) score.

DESIGN: Observational cohort study using data from the American College of Veterinary Emergency and Critical Care Veterinary Committee on Trauma (VetCOT) trauma registry acquired between September 2013 and October 2017.

SETTING: Nine Level I and Level II veterinary trauma centers.

ANIMALS: Nine hundred eighty-four dogs assessed within 24 h of traumatic injury.

INTERVENTIONS: None.

MEASUREMENTS AND MAIN RESULTS: Patient mortality was 10.8%. The VetCOT model was constructed based on 4 variables: plasma lactate and ionized calcium obtained within 6 h of admission, and presence or absence of clinical signs consistent with either head or spinal trauma. The VetCOT score had good discriminatory performance (AUROC = 0.87, 95% CI = 0.83-0.91) comparable to that of the 6 variable ATT score for the same population (area under the receiver operator characteristic [AUROC] = 0.87; 95% CI, 0.84-0.90). No statistical difference in discriminatory performance between the 2 scores was identified (P = 0.98). The VetCOT score showed good calibration on this population (Hosmer-Lemeshow test P = 0.93), whereas the ATT score failed to calibrate (P = 0.02) due to overprediction of mortality at low scores. Sensitivity and specificity for outcome of the VetCOT score at a risk probability cutoff of 0.5 for this population were 28.97% and 97.95%, respectively.

CONCLUSIONS: The VetCOT score is a more parsimonious model with comparable discriminatory performance and superior calibration to the ATT score for risk stratification in dogs following trauma. Further prospective validation studies are required to confirm the discriminatory performance of the VetCOT score.

PMID:34499798 | DOI:10.1111/vec.13135

Am J Hum Biol. 2021 Sep 9:e23679. doi: 10.1002/ajhb.23679. Online ahead of print.

ABSTRACT

BACKGROUND: Digit ratio (2D:4D), a putative marker of prenatal testosterone, is a negative correlate of sports, athletic, and fitness performance.

OBJECTIVES: To describe the relationship between 2D:4D and vertical jump performance in athletes.

METHODS: Sixty-one Division I American Football players from a Midwestern U.S. university had their 2D:4D measured digitally and their vertical jump performance measured using jump mechanography. The primary outcome was jump height, with secondary outcomes depicting jump execution also recorded. Linear relationships between 2D:4D and vertical jump performance were quantified using partial correlations adjusted for age, height, mass, and ethnicity.

RESULTS: 2D:4D was a statistically significant weak negative correlate of jump height (partial r [95% confidence interval]: -0.26 [-0.48, -0.01]), indicating that athletes with lower 2D:4Ds (i.e., relatively longer 4th digits) jumped higher. Relationships with jump execution variables were negligible to weak and negative, but not statistically significant.

CONCLUSIONS: The significant relationship between 2D:4D and jump height probably reflects both the long-term organizational and short-term activational benefits of testosterone. Therefore, 2D:4D may be a useful indicator of explosive strength among young athletes.

PMID:34499783 | DOI:10.1002/ajhb.23679

J Magn Reson Imaging. 2021 Sep 9. doi: 10.1002/jmri.27912. Online ahead of print.

ABSTRACT

BACKGROUND: Brain tissue hypoxia is a common consequence of traumatic brain injury (TBI) due to the rupture of blood vessels during impact and it correlates with poor outcome. The current magnetic resonance imaging (MRI) techniques are unable to provide a direct map of tissue hypoxia.

PURPOSE: To investigate whether GdDO3NI, a nitroimidazole-based T₁ MRI contrast agent allows imaging hypoxia in the injured brain after experimental TBI.

STUDY TYPE: Prospective.

ANIMAL MODEL: TBI-induced mice (controlled cortical impact model) were intravenously injected with either conventional T₁ agent (gadoteridol) or GdDO3NI at 0.3 mmol/kg dose (n = 5 for each cohort) along with pimonidazole (60 mg/kg) at 1 hour postinjury and imaged for 3 hours following which they were euthanized.

FIELD STRENGTH/SEQUENCE: 7 T/T₂ -weighted spin echo and T₁ -weighted gradient echo.

ASSESSMENT: Injured animals were imaged with T₂ -weighted spin-echo sequence to estimate the extent of the injury. The mice were then imaged precontrast and postcontrast using a T₁ -weighted gradient-echo sequence for 3 hours postcontrast. Regions of interests were drawn on the brain injury region, the contralateral brain as well as on the cheek muscle region for comparison of contrast kinetics. Brains were harvested immediately post-imaging for immunohistochemical analysis.

STATISTICAL TESTS: One-way analysis of variance and two-sample t-tests were performed with a P < 0.05 was considered statistically significant.

RESULTS: GdDO3NI retention in the injury region at 2.5-3 hours post-injection was significantly higher compared to gadoteridol (mean retention fraction 63.95% ± 27.43% vs. 20.68% ± 7.43% for gadoteridol at 3 hours) while it rapidly cleared out of the muscle region. Pimonidazole staining confirmed the presence of hypoxia in both gadoteridol and GdDO3NI cohorts, and the later cohort showed good agreement with MRI contrast enhancement.

DATA CONCLUSION: GdDO3NI was successfully shown to visualize hypoxia in the brain post-TBI using T₁ -weighted MRI at 2.5-3 hours postcontrast.

EVIDENCE LEVEL: 1 TECHNICAL EFFICACY: Stage 1.

PMID:34499791 | DOI:10.1002/jmri.27912

J Magn Reson Imaging. 2021 Sep 9. doi: 10.1002/jmri.27917. Online ahead of print.

ABSTRACT

BACKGROUND: Arterial spin labeling (ASL) has been proven to be effective in ischemia-induced acute kidney injury (AKI); however, validation of ASL magnetic resonance imaging (MRI) is limited in AKI in the presence of cirrhosis.

PURPOSE: To investigate the feasibility of ASL in revealing renal blood flow (RBF) changes in kidney injury in the presence of cirrhosis and to assess its value in the early diagnosis of disease.

STUDY TYPE: Longitudinal.

ANIMAL MODEL: Rats were randomized into baseline group (N = 3), sham surgery group (N = 18), and common bile duct ligation (BDL) group (N = 48). All groups were divided into six subgroups based on different sacrificed time points.

FIELD STRENGTH/SEQUENCE: 3 T scanner, prototypic pulsed ASL sequence using flow-sensitive alternating inversion recovery preparation, half-Fourier acquisition single-shot turbo spin echo sequence.

ASSESSMENT: RBF measurement was performed by ASL. Hematoxylin-eosin (HE) score, Hypoxia-inducible factor-1alpha (HIF-1α) score, peritubular capillar (PTC) density, alanine aminotransferase, aspartate aminotransferase, serum total bilirubin, total bile acids, serum creatinine (Scr), and blood urea nitrogen (BUN) were harvested.

STATISTICAL TESTS: Analysis of variance, Pearson’s correlation coefficient, and receiver operating characteristic curves were performed. P < 0.05 was considered statistically significant.

RESULTS: RBF, HE score, HIF-1α score, and PTC density after BDL were significantly different from baseline. RBF was highly correlated with HE score, HIF-1α score, and PTC density (r = -0.7598, r = -0.7434, r = 0.6406, respectively). RBF and Scr began to differ significantly from baseline at day 3 and 7 after intervention, respectively. The areas under the curves of RBF, Scr, and BUN for distinguishing non-AKI from AKI in cirrhosis were 1.00, 0.888, and 0.911, while those for distinguishing mild from severe kidney injury were 0.961, 0.830, and 0.857, respectively.

DATA CONCLUSION: ASL allows the longitudinal assessment of the degree of AKI induced by cholestatic cirrhosis in rats and can serve as a noninvasive marker for the early and accurate diagnosis of AKI.

LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY STAGE: 2.

PMID:34499757 | DOI:10.1002/jmri.27917

Biom J. 2021 Sep 9. doi: 10.1002/bimj.202000077. Online ahead of print.

ABSTRACT

Skewed distributions and inferences concerning quantiles are common in the health and social science researches. And most standard simultaneous inference procedures require the normality assumption. For example, few methods exist for comparing the medians of independent samples or quantiles of several distributions in general. To our knowledge, there is no easy-to-use method for constructing simultaneous confidence intervals for multiple contrasts of quantiles in a one-way layout. In this paper, we develop an asymptotic method for constructing such intervals both for differences and ratios of quantiles and extend the idea to that of right-censored time-to-event data in survival analysis. Small-sample performance of the proposed method and a bootstrap method were assessed in terms of coverage probabilities and average widths of the simultaneous confidence intervals. Good coverage probabilities were observed for most of the distributions considered in our simulations. The proposed methods have been implemented in an R package and are used to analyze two motivating datasets.

PMID:34499768 | DOI:10.1002/bimj.202000077

J Am Geriatr Soc. 2021 Sep 9. doi: 10.1111/jgs.17445. Online ahead of print.

ABSTRACT

BACKGROUND: Historically, older adults have been excluded from trials evaluating hepatitis C virus (HCV) treatment, in part, due to the adverse effects associated with previous regimens. Veterans are at high risk of HCV infection. Ledipasvir/sofosbuvir (LED/SOF) is a once daily antiviral regimen with demonstrated efficacy and tolerability among the younger population. We examined the tolerability and effectiveness of LED/SOF in Veterans age ≥65 years versus those <65 years who were treated at the Atlanta VA Health Care System (AVAHCS).

METHODS: Using the VA Clinical Case Registry, all persons who filled a LED/SOF prescription at the AVAHCS from January 1, 2015, through March 31, 2016, were identified. The electronic medical records were reviewed to identify basic demographic information: comorbidities; polypharmacy; and outcomes. Sustained virologic response (SVR) was defined as an undetectable HCV RNA, at least 12 weeks after completing treatment. Descriptive statistics were employed using SAS v9.2.

RESULTS: We identified 345 Veterans who filled LED/SOF during the study period; 94 were excluded due to exposure to ribavirin and IFN containing regimens; 97 (38.6%) were ≥65 years. Veterans were predominantly black (57%) and male (97%). Cancer was more prevalent among older Veterans (p = 0.047) as was polypharmacy (p = 0.001). Treatment completion rates between older and younger Veterans were not significantly different (99 vs. 95%, respectively; p = 0.16), but significantly more older Veterans achieved SVR (98 vs. 91%; p = 0.03).

CONCLUSIONS: LED/SOF was a well-tolerated and effective regimen in an older Veteran population despite their multiple comorbidities and polypharmacy presence.

PMID:34499744 | DOI:10.1111/jgs.17445

Int J Gynaecol Obstet. 2021 Sep 9. doi: 10.1002/ijgo.13917. Online ahead of print.

ABSTRACT

OBJECTIVE: To describe risk factors and outcomes of pregnant women infected with SARS-CoV-2 admitted to South African healthcare facilities.

METHODS: A population-based cohort study was conducted utilizing an amended International Obstetric Surveillance System protocol. Data on pregnant women with SARS-CoV-2 infection, hospitalized between April 14, 2020, and November 24, 2020, were analyzed.

RESULTS: A total of 36 hospitals submitted data on 673 infected hospitalized pregnant women; 217 (32.2%) were admitted for COVID-19 illness and 456 for other indications. There were 39 deaths with a case fatality rate of 6.3%: 32 (14.7%) deaths occurred in women admitted for COVID-19 illness compared to 7 (1.8%) in women admitted for other indications. Of the women, 106 (15.9%) required critical care. Maternal tuberculosis, but not HIV co-infection or other co-morbidities, was associated with admission for COVID-19 illness. Rates of cesarean delivery did not differ significantly between women admitted for COVID-19 and those admitted for other indications. There were 179 (35.4%) preterm births, 25 (4.7%) stillbirths, 12 (2.3%) neonatal deaths, and 162 (30.8%) neonatal admissions. Neonatal outcomes did not differ significantly from those of infected women admitted for other indications.

CONCLUSION: The maternal mortality rate was high among women admitted with SARS-CoV-2 infection and higher in women admitted primarily for COVID-19 illness with tuberculosis being the only co-morbidity associated with admission.

PMID:34499750 | DOI:10.1002/ijgo.13917