Tag: statistics

J Stroke Cerebrovasc Dis. 2021 Mar 3;30(5):105683. doi: 10.1016/j.jstrokecerebrovasdis.2021.105683. Online ahead of print.

ABSTRACT

OBJECTIVES: To develope and validate a nomogram to predict the probability of deep venous thrombosis (DVT) in patients after acute stroke during the first 14 days with clinical features and easily obtainable biochemical parameters.

METHODS: This is a single-center prospective cohort study. The potential predictive variables for DVT at baseline were collected, and the presence of DVT was evaluated using ultrasonography within the first 14 days. Data were randomly assigned to either a modeling data set or a validation data set. Univariable and Multivariate logistic regression analysis was used to develop risk scores to predict DVT in the modeling data set and the area under the receiver operating characteristic curve to validate the score in the test data set, and nomogram and calibration curve were constructed by R project.

RESULTS: A total of 1651 patients with acute stroke were enrolled in the study. The overall incidence of DVT after acute stroke within two weeks was 14.4%. Multivariable analysis detected older age (≥65 years),female gender, hemorrhagic stroke, malignancy, lower limb muscle strength<3 grade, Albumin<40 g·L^-1 and D-dimer>0.5 mg·L^-1 were highly predictive of 14-day risk of DVT. The AUC of the nomogram with these above-mentioned independent risk factors to predict the 14-day risk of DVT was 0.756 (95% CI, 0.712-0.812) and 0.811 (95%CI, 0.762-0.859) for the modeling cohort and external validation cohort, respectively. Moreover, the calibration of the nomogram showed a nonsignificant Hosmer-Lemeshow test statistic in the modeling (P = 0.250) and validation sets (P = 0.995). With respect to decision curve analyses, the nomogram exhibited preferable net benefit gains than the staging system across a wide range of threshold probabilities.

CONCLUSION: This nomogram had a good performance in predictive accuracy, discrimination capability, and clinical utility, which was helpful for clinicians to identify high-risk groups of DVT and formulate relevant prevention and treatment measures.

PMID:33676327 | DOI:10.1016/j.jstrokecerebrovasdis.2021.105683

Clin Imaging. 2021 Feb 3;77:122-129. doi: 10.1016/j.clinimag.2021.01.033. Online ahead of print.

ABSTRACT

PURPOSE: To identify CT parameters useful for assessment of pulmonary hypertension (PH) in patients with severe aortic stenosis (AS).

MATERIALS AND METHODS: Retrospective study of 165 patients who had undergone right heart catheterization (RHC), and CTA of the thorax for preoperative aortic valve replacement (TAVR) planning. These were divided into groups based on mean pulmonary artery (PA) pressure (mPAP) of 25 mm Hg on RHC (85 cases and 80 controls). Diameters of main pulmonary artery diameter (MPAD), left pulmonary artery (LPA), right pulmonary artery (RPA), and maximal long axis and short axis diameters of the right atrium (RA) and ventricle (RV) were measured on the axial plane. Univariate and multivariate statistical analysis was utilized to identify metrics predictive of PH.

RESULTS: MPAD, LPA, and RPA were higher in subjects with mPAP >25 mm Hg (p < 0.0001 for all). Thresholds of 30.5 mm for MPAD (68.4% sensitivity, 82.7% specificity), and 27.5 mm for LPA and RPA (LPA: 51.9% sensitivity, 78.8% specificity; RPA: 62.0% sensitivity, 78.8% specificity) provided the best discrimination of elevated mPAP. Compared to literature values for MPAD (28.9 mm in men and 26.9 mm in women), these thresholds provide lower sensitivity but greatly increased specificity. Inclusion of RA enlargement to MPAD increased specificity to 98.5%, while inclusion of RV enlargement increased specificity to 100%.

CONCLUSION: Threshold to identify PH in patients with AS using PA enlargement is higher than previously reported range for normal. Inclusion of RA and RV enlargement improves the ability of CT to more accurately identify PH in patients with AS.

PMID:33676129 | DOI:10.1016/j.clinimag.2021.01.033

J Environ Manage. 2021 Mar 3;286:112254. doi: 10.1016/j.jenvman.2021.112254. Online ahead of print.

ABSTRACT

In this study, the pure terephthalic acid sludge was treated by a drying process which was an economical and environmentally method. The water change and metabolic pathways for bacterial community function prediction were analyzed. The microbial community changes were studied by high-throughput sequencing to draw the dynamic succession model. Then multiple statistics was used to determine the key factors of the reduction. The results showed that the main stage of water loss in the PTA sludge drying process was the high temperature period where the water lost by evaporation accounted for more than 90% of the total removal. The main metabolic pathways for bacterial community function were amino acid (7.72%-8.71% of Kyoto encyclopedia of genes and genomes relative abundance and 8.26%-9.51% of Cluster of orthologous groups of proteins relative abundance) and carbohydrate metabolism. The model describing the dynamic succession of microbial communities showed that the dominant bacteria changed from Nitrospira, Novosphingobium and Azohydromonas to Pseudomonas, Paeniglutamicibac and Pelotomaculum. The key factors for water loss were Gemmatimonas, Novosphingobium and Azohydromonas with the correlation coefficients of 0.887, 0.772, 0.783, respectively; the key factors for dry matter loss were Pelotomaculum, total organic matter, dissovlved organic carbon and carbon/nitrogen ratio; the key factors for toxic substance loss were Brevundimonas, Novosphingobium and Gemmatimonas. These results provided theoretical support for the application and demonstration for hazardous waste sludge reduction.

PMID:33676131 | DOI:10.1016/j.jenvman.2021.112254

Vision Res. 2021 Mar 3;183:41-52. doi: 10.1016/j.visres.2021.01.011. Online ahead of print.

ABSTRACT

How non-symbolic numerosity is visually extracted remains a matter of intense debate. Most evidence suggests that numerosity is directly extracted on individual objects following Weber’s law, at least for a moderate numerical range. Alternative accounts propose that, whatever the range, numerosity is indirectly derived from summary texture-statistics of the raw image such as spatial frequency (SF). Here, to disentangle these accounts, we tested whether the well-known behavioural signature of numerosity encoding (ratio effect) is preserved despite the equalisation of the SF content. In Experiment 1, participants had to select the numerically larger of two briefly presented moderate-range numerical sets (i.e., 8-18 dots) carefully matched for SF; the ratio between numerosities was manipulated by levels of increasing difficulty (e.g., 0.66, 0.75, 0.8). In Experiment 2, participants performed the same task, but they were presented with both the original and SF equalised stimuli. In both experiments, the results clearly showed a ratio-dependence of the performance: numerosity discrimination became harder and slower as the ratio between numerosities increased. Moreover, this effect was found to be independent of the stimulus type, although the overall performance was better with the original rather than the SF equalised stimuli (Experiment 2). Taken together, these findings indicate that the power spectrum per se cannot explain the main behavioural signature of Weber-like encoding of numerosities (the ratio effect), at least over the tested numerical range, partially challenging alternative indirect accounts of numerosity processing.

PMID:33676137 | DOI:10.1016/j.visres.2021.01.011

Eur J Obstet Gynecol Reprod Biol. 2021 Feb 24;259:146-152. doi: 10.1016/j.ejogrb.2021.02.023. Online ahead of print.

ABSTRACT

OBJECTIVE: During the past three decades, applying IVF for infertility treatment PCOS women has increased significantly, and the landscape of treatment strategies has changed dramatically. However, early review of IVF on PCOS have insufficiently accounted for efficacy and safety of the technic. With abundant studies in recent years, there is a need to reconcile these new data.

MATERIAL AND METHODS: To compare reproductive and obstetric outcomes of IVF between women with and without PCOS, a meta-analysis of 95 studies involving more than 21289 PCOS patients and 43036 controls was performed.

RESULTS: Despite longer stimulation duration (WMD = 0.34 day, 95 % CI: 0.09, 0.59) and lower dose of Gn required (WMD = -361.3 IU, 95 % CI: -442.3, -280.4), more oocytes (WMD = 3.67, 95 % CI: 3.14-4.21) and matured oocytes (WMD = 2.16, 95 % CI: 1.52-2.80) per cycle were obtained from PCOS women. There were no statistically significant differences for cleavage, high-grade embryo and implantation rate. Although similar pregnancy and live birth rates per cycle were achieved in PCOS and non-PCOS women after IVF, women with PCOS still suffered from significantly increased risks of miscarriage (OR = 1.44, 95 % CI: 1.20-1.72), biochemical pregnancy loss (OR = 1.89, 95 % CI: 1.48-2.41), and OHSS (OR = 3.58, 95 % CI: 2.86-4.48), in addition to lower fertilization rate (OR = 0.79, 95 % CI: 0.71-0.88). Adverse obstetric outcomes including ectopics pregnancy and multiple pregnancies are comparable between two groups. The overall cycle cancellation rate was significantly higher among PCOS women with OR of 2.55 (95 % CI: 1.67-3.89), and concern over OHSS or hyper-response constitute the main cause. Similar results were also observed after stratified analysis.

CONCLUSIONS: Our results support the effectiveness of IVF for infertility treatment among PCOS patients. However, options to minimize adverse outcomes regarding to lower fertilization, miscarriage, biochemical pregnancy loss and OHSS are required. Further studies elucidating detailed mechanism underlying these adverse outcomes could be of great importance to improve the experience of IVF treatment.

PMID:33676123 | DOI:10.1016/j.ejogrb.2021.02.023

Ophthalmol Glaucoma. 2021 Mar 3:S2589-4196(21)00043-0. doi: 10.1016/j.ogla.2021.02.003. Online ahead of print.

ABSTRACT

PURPOSE: To compare the characteristics of the peripapillary choroid (PPC) between the two eyes of patients with unilateral treatment-naïve normal tension glaucoma (NTG).

DESIGN: Observational case series.

PARTICIPANTS: Sixty-nine patients (138 eyes) with treatment-naive unilateral NTG.

METHODS: The characteristics of PPC vasculature were evaluated by measuring PPC thickness and assessing the presence of parapapillary deep-layer microvasculature dropout (MvD). PPC thickness was measured by enhanced depth imaging optical coherence tomography (OCT). MvD was assessed using OCT angiography. The area and maximum radial width of β-zone parapapillary atrophy (PPA) were measured on infra-red images using the built-in caliper tool of the Spectralis OCT.

MAIN OUTCOME MEASURES: Between-eye differences in PPC thickness, MvD frequency, and the area and maximum width of β-zone PPA.

RESULTS: Eyes with NTG had higher intraocular pressure (IOP), longer axial length, thinner PPC, larger area and maximum radial width of the β-zone PPA, and more frequent MvD (P < 0.01 each) than contralateral healthy eyes. Multivariate conditional logistic regression analysis revealed that higher IOP, thinner PPC, larger maximum radial width of β-zone PPA, and the presence of MvD were independently associated with the risk of NTG (P < 0.03 each). MvD location and retinal nerve fiber layer defect were topographically correlated in eyes with NTG.

CONCLUSIONS: PPC vasculature characteristics are significantly more compromised in eyes with NTG than in contralateral healthy eyes of patients with unilateral NTG.

PMID:33676067 | DOI:10.1016/j.ogla.2021.02.003

Am J Emerg Med. 2021 Feb 24;45:80-85. doi: 10.1016/j.ajem.2021.02.046. Online ahead of print.

ABSTRACT

BACKGROUND: Children with traumatic head injury are often transferred from community Emergency Departments (ED) to a Pediatric Emergency Department (PED). The primary objective of this study was to describe the outcomes of minor head injury (MHI) transfers to a PED. The secondary objective was to report Computed Tomography (CT) utilization rates for MHI.

METHODS: We conducted a retrospective study of children aged ≤18 years transferred to our PED for MHI from 2013 to 2018. Patients with Glasgow Coma Scale (GCS) < 14, coagulopathies, history of brain mass/shunt and suspected non-accidental trauma were excluded. Data collected included demographics, interventions performed, and disposition. MHI risk stratification and clinically important traumatic brain injury (ciTBI) were defined per the Pediatric Emergency Care Applied Research Network (PECARN) head injury guidelines. Descriptive statistics were reported using general measures of frequency and central tendency.

RESULTS: A total of 1078 children with MHI were analyzed based on eligibility criteria. The majority of patients were male (62%) and ≥ 2 years of age (69.3%). Subspecialist consultation (57.2%) and neuroimaging (27.4%) were the most commonly performed interventions in the PED. Only 14 children (1.3%) required neurosurgical intervention. One-third of the transferred patients required no additional work-up. Two-thirds of the patients (66.6%) were directly discharged from the PED. Though the total number of MHI transfers per year declined steadily during the study period (from 271/year to 119/year), CT head utilization remained relatively similar across the study years (60.3% to 70.8%). A higher proportion of children received CT in the ED when compared to the PED for low-risk (28.9% vs 15.8%) and intermediate-risk groups (42.8% vs 29.4%).

CONCLUSIONS: The majority of pediatric MHI transfers are discharged home following a subspecialty consultation and/or neuroimaging. Despite guidelines and a low incidence of ciTBI, CT utilization remains high in the intermediate and low risk MHI groups, especially in the community settings. Targeted interventions are needed to reduce the potentially avoidable transfers and low-value performance of CT in children with MHI.

PMID:33676080 | DOI:10.1016/j.ajem.2021.02.046

Mar Pollut Bull. 2021 Mar 3;166:112040. doi: 10.1016/j.marpolbul.2021.112040. Online ahead of print.

ABSTRACT

Levrier Bay is an important fishing area which is under growing anthropogenic pressures seriously threatening this treasure. Among these pressures Polycyclic Aromatic Hydrocarbon are of great environmental concern. Therefore, 16 EPA-PAHs were analyzed using GC-MS in Perna perna species and sediment. Comparison with Dakar (Senegal) and Moroccan coasts shows that PAHs levels are strikingly lower than that of heavily polluted Dakar coast (2474 μg/kg); nevertheless, comparable to Moroccan Casablanca and Tangier coasts (245 and 351 μg/kg, respectively). Ratio analysis indicates the predominance of pyrogenic sources and partial contribution of automotive traffic for the half of 4 sites. Furthermore, statistical analys shows that there are no significative differences, except for Benzo(b)Fluorentene in P. perna tissue and 4 PAHs (Fluorene; Fluorenthene; Pyrene; diBenzo(ah)Anthracene and dBahANT) in sediment for sites samples. Furthermore, bioconcentration indicates that P. perna is an excellent PAHs bioindicator. This points the necessity for immediate introduction of a sound Pollutants monitoring system.

PMID:33676109 | DOI:10.1016/j.marpolbul.2021.112040

Spine J. 2021 Mar 3:S1529-9430(21)00108-X. doi: 10.1016/j.spinee.2021.03.001. Online ahead of print.

ABSTRACT

BACKGROUND CONTEXT: Recent media coverage of overlapping surgery has led to several studies investigating public perception of concurrent and overlapping surgery, both of which involve a single attending surgeon working on two separate cases in two separate operating rooms. In concurrent surgery, the critical periods of the surgeries overlap, while in overlapping surgery they do not. The literature revealed a general lack of knowledge about these practices and strong disapproval of their use by the public.

PURPOSE: To determine the comfort level of spine surgery patients and their family members toward concurrent and overlapping surgery.

STUDY DESIGN/SETTING: This cross-sectional survey study was performed at an urban, adult academic spine surgery clinic.

PATIENT SAMPLE: Patients and their companions who were waiting to be seen at their initial clinic visit or follow-up visit were approached to participate in the study.

OUTCOME MEASURES: The survey queried respondents’ baseline knowledge of and comfort level with concurrent and overlapping surgery, in addition to comfort level with different levels of surgical trainees on a 5-point Likert scale.

METHODS: A five-section, 36-item questionnaire was administered by a research assistant to respondents over a three-month period spanning June 2019 – August 2019. A research assistant described the terms overlapping surgery and concurrent surgery to participants of the survey using diagrams and a pre-formulated script after self-reported knowledge questions. Statistical analysis was performed using the chi-square test for categorical variables, and Kendall’s tau-c rank correlation coefficient with ordinal independent variables for correlations.

RESULTS: Knowledge about concurrent and overlapping surgery was low in our study population (8.22% and 6.16%, respectively). Over half of respondents reported that they felt comfortable with overlapping surgery (58.22%). Most respondents reported that they would like their surgeon to disclose the participation of surgical trainees (residents and fellows) in their surgery (98%). In addition, the 4^th and 5^th years of surgical training were associated with a significant increase in patient comfort with surgical trainee participation. There was no difference in response distribution between patients versus non-patients.

CONCLUSIONS: Knowledge about concurrent and overlapping surgery remains poor in our study population. Lack of general knowledge about overlapping surgery can be a serious impediment to obtaining informed consent, and further study is required to determine the best methods to raising patient awareness.

PMID:33676019 | DOI:10.1016/j.spinee.2021.03.001

J Hum Evol. 2021 Mar 3;153:102950. doi: 10.1016/j.jhevol.2021.102950. Online ahead of print.

ABSTRACT

Archaeological remains have highlighted the fact that the interglacial Marine Isotope Stage (MIS) 11 was a threshold from the perspective of hominin evolution in Europe. After the MIS 12 glaciation, considered one of the major climate-driven crises experienced by hominins, the archaeological records show an increasing number of occupations, evidence of new subsistence behaviors, and significant technical innovations. Here, we used statistical and geographic techniques to analyze the amphibian- and reptile-based paleoclimate and habitat reconstructions generated from a large data set of the Iberian Peninsula to (1) investigate if temperature, precipitation, and/or forest cover may have impacted the hominin occupation of the territory during the Early and Middle Pleistocene, (2) propose an ‘Iberian’ ecological model before and after the MIS 12/11 transition, and (3) evaluate, based on this model, the potential hominin occupation at a European scale. The results indicate the existence of climatic constraints on human settlement related to rainfall and environmental humidity. The Early Pleistocene and the first half of the Middle Pleistocene are dominated by the occupation of relatively humid wooded areas, whereas during the second part of the Middle Pleistocene, a broadening of the earlier ecological niche is clearly observed toward the occupation of more open arid areas. Based on the estimated occupational niche for hominins, a maximum potential distribution for early hominins is proposed in Europe before and after 426 ka. Results also indicate that parts of the Iberian Peninsula may not have been suitable for early hominin occupation. Our ecological model is consistent with the pattern of hominin occupation observed in northern and central Europe, where the earliest evidence reflects only pioneering populations merely extending their ranges in response to the expansion of their preferred habitats, as compared with a more sustained occupation by 400 ka.

PMID:33676058 | DOI:10.1016/j.jhevol.2021.102950