Tag: statistics

Alzheimers Dement. 2023 May 12. doi: 10.1002/alz.13113. Online ahead of print.

ABSTRACT

INTRODUCTION: Recent genome-wide association studies identified new dementia-associated variants. We assessed the performance of updated polygenic risk scores (PRSs) using these variants in an independent cohort.

METHODS: We used Cox models and area under the curve (AUC) to validate new PRSs (PRS-83SNP, PRS-SBayesR, and PRS-CS) compared with an older PRS-23SNP in 12,031 initially-healthy participants ≥70 years of age. Dementia was rigorously adjudicated according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria.

RESULTS: PRS-83SNP, PRS-SBayesR, and PRS-CS were associated with incident dementia, with fully adjusted (including apolipoprotein E [APOE] ε4) hazard ratios per standard deviation (SD) of 1.35 (1.23-1.47), 1.37 (1.25-1.50), and 1.42 (1.30-1.56), respectively. The AUC of a model containing conventional/non-genetic factors and APOE was 74.7%. This was improved to 75.7% (p = 0.007), 76% (p = 0.004), and 76.1% (p = 0.003) with addition of PRS-83SNP, PRS-SBayesR, and PRS-CS, respectively. The PRS-23SNP did not improve AUC (74.7%, p = 0.95).

CONCLUSION: New PRSs for dementia significantly improve risk-prediction performance, but still account for less risk than APOE genotype overall.

PMID:37177856 | DOI:10.1002/alz.13113

J Magn Reson Imaging. 2023 May 13. doi: 10.1002/jmri.28770. Online ahead of print.

ABSTRACT

BACKGROUND: The diagnosis of prenatal placenta accreta spectrum (PAS) with magnetic resonance imaging (MRI) is highly dependent on radiologists’ experience. A deep learning (DL) method using the prior knowledge that PAS-related signs are generally found along the utero-placental borderline (UPB) may help radiologists, especially those with less experience, to mitigate this issue.

PURPOSE: To develop a DL tool for antenatal diagnosis of PAS using T2-weighted MR images.

STUDY TYPE: Retrospective.

SUBJECTS: Five hundred and forty pregnant women with clinically suspected PAS disorders from two institutions, divided into training (409), internal test (103), and external test (28) datasets.

FIELD STRENGTH/SEQUENCE: Sagittal T2-weighted fast spin echo sequence at 1.5 T and 3 T.

ASSESSMENT: An nnU-Net was trained for placenta segmentation. The UPB straightening approach was used to extract the utero-placental boundary region. The UPB image was then fed into DenseNet-PAS for PAS diagnosis. DenseNet-PP learnt placental position information to improve the PAS diagnosis performance. Three radiologists with 8, 10, and 12 years of experience independently evaluated the images. Two radiologists marked the placenta tissue. Histopathological findings were the reference standard.

STATISTICAL TESTS: Area under the curve (AUC) was used to evaluate the classification. Dice coefficient evaluated the segmentation between radiologists and the model performance. The Mann-Whitney U-test or the chi-squared test assessed the significance of differences. Decision curve analysis was used to determine clinical effectiveness. DeLong’s test was used to compare AUCs.

RESULTS: Of the 540 patients, 170 had PAS disorders confirmed by histopathology. The DL model using UPB images and placental position yielded the highest AUC of 0.860 and 0.897 in internal test and external test cohorts, respectively, significantly exceeding the performance of three radiologists (internal test AUC, 0.737-0.770).

DATA CONCLUSION: By extracting the UPB image, this fully automatic DL pipeline achieved high accuracy and may assist radiologists in PAS diagnosis using MRI.

LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY: Stage 2.

PMID:37177832 | DOI:10.1002/jmri.28770

Acta Psychiatr Scand. 2023 May 12. doi: 10.1111/acps.13568. Online ahead of print.

ABSTRACT

OBJECTIVES: The augmentation of serotonin reuptake inhibitors (SRIs) can be achieved by add-on therapy with different pharmacological agents in obsessive-compulsive disorder (OCD) for a better clinical outcome. This network meta-analysis (NMA) was conducted to evaluate and compare the effects of available augmentation agents for SRIs in OCD.

METHOD: The data was extracted from 59 relevant clinical trials after a literature search on MEDLINE/PubMed, Scopus, Cochrane databases and clinical trial registries. PRISMA guidelines were followed in data extraction, analysis and reporting. Random effects Bayesian NMA was done to pool the effects across the interventions for the change in Yale-Brown Obsessive-Compulsive Scale (YBOCS) scoring from baseline to the end of the study. Network graph was built, consistency model was run, node splitting analysis was performed, treatments were ranked as per SUCRA score and meta-regression was done for refractoriness to SRIs and duration of augmentation therapy as the predictor variables.

RESULTS: The drugs showing significant reduction in YBOCS scoring were pregabalin (MD:-8.1;95% CrI: -16, -0.43), memantine (MD:-6.2;95% CrI: -9.9, -2.3), lamotrigine (MD:-6;95% CrI: -12, -0.47), ondansetron (MD:-5.7;95% CrI: -11, -0.67), granisetron (MD:-5.6;95% CrI: -11, -0.44), aripiprazole (MD:-5.4;95% CrI:-9.1, -1.6), risperidone (MD:-3.3;95% CrI: -6.4, -0.20) and topiramate (MD:-5.3;95% CrI: -9.6, -0.97). The node-split analysis showed that direct and indirect pooled effect sizes for all comparisons were comparable. Meta-regression showed a statistically non-significant association between YBOCS score reduction with the duration of augmentation therapy, but significant with SRI-refractory status. Finally, the results were sorted based on certainty of evidence.

CONCLUSION: Memantine was found to be most effective augmentation agent for SRIs in OCD, followed by lamotrigine, ondansetron and granisetron with moderate certainty of evidence. The augmentation agents showed better symptom reduction in patients with SRI-refractory OCD in comparison to non-refractory OCD.

PROSPERO REGISTRATION: CRD42022360110.

PMID:37177823 | DOI:10.1111/acps.13568

Int J Gynaecol Obstet. 2023 May 13. doi: 10.1002/ijgo.14835. Online ahead of print.

ABSTRACT

OBJECTIVE: To describe and compare the annual success rates of medical treatment in the analyzed period and to evaluate the associated factors.

METHODS: Retrospective study with 158 women with tubal pregnancy followed up over 17 years. Statistical analysis was performed using the Cochran-Armitage test, the χ² test, Mann-Whitney test, and multiple logistic regression.

RESULTS: The success rate was 47.4%. There was a trend of significant change in the success rate of clinical treatment over time (Z = 2.01, P = 0.044); it was associated to undergoing treatment between 2012 and 2017 (P = 0.028), the absence of abdominal pain (P = 0.020), receiving a higher dose of methotrexate (P < 0.001), and less time hospitalized (P < 0.001). In the final statistical model, we observed that receiving a higher dose of methotrexate (P = 0.025, odds ratio [OR] 1.03, 95% confidence interval [CI] 1.00-1.06), having a low serum β-HCG concentration before treatment (P = 0.003, OR 0.87, 95% CI 0.79-0.95), and not having abdominal pain (P = 0.004, OR 4.26, 95% CI 1.61-11.28) were factors associated with a higher chance of successful clinical treatment for tubal pregnancy.

CONCLUSION: A greater chance of success was observed among women undergoing clinical treatment from 2012 onwards, who used higher doses of methotrexate, were asymptomatic at admission, and had low concentrations of β-hCG.

PMID:37177821 | DOI:10.1002/ijgo.14835

Ann Bot. 2023 May 13:mcad047. doi: 10.1093/aob/mcad047. Online ahead of print.

ABSTRACT

BACKGROUND AND AIMS: Hybridization has long been recognized as an important process for plant evolution and is often accompanied by polyploidization, another prominent force in generating biodiversity. Despite its pivotal importance in evolution, the actual prevalence and distribution of hybridization across the tree of life remain unclear.

METHODS: We used whole-genome shotgun (WGS) sequencing and cytological data to investigate the evolutionary history of Henckelia, a large genus in the family Gesneriaceae with a high frequency of suspected hybridization and polyploidization events. We generated WGS sequencing data at about 10× coverage for 26 Chinese Henckelia species plus one Sri Lanka species. To untangle the hybridization history, we separately extracted whole plastomes and thousands of single-copy nuclear genes from the sequencing data, and reconstructed phylogenies based on both nuclear and plastid data. We also explored sources of both genealogical and cytonuclear conflicts and identified signals of hybridization and introgression within our phylogenomic dataset using several statistical methods. Additionally, to test the polyploidization history, we evaluated chromosome counts for 45 populations of the studied 27 Henckelia species.

KEY RESULTS: We obtained well-supported phylogenetic relationships using both concatenation and coalescent-based methods. However, the nuclear phylogenies were highly inconsistent with the plastid phylogeny, and we observed intensive discordance among nuclear gene trees. Further analyses suggested that both incomplete lineage sorting (ILS) and gene flow contributed to the observed cytonuclear and genealogical discordance. Our analyses of introgression and phylogenetic networks revealed a complex history of hybridization within the genus Henckelia. In addition, based on chromosome counts for 27 Henckelia species, we found independent polyploidization events occurred within Henckelia after different hybridization events.

CONCLUSIONS: Our findings demonstrated that hybridization and polyploidization are common in Henckelia. Furthermore, our results revealed that H. oblongifolia is not a member of the redefined Henckelia and suggested several other taxonomic treatments in this genus.

PMID:37177810 | DOI:10.1093/aob/mcad047

Acta Odontol Scand. 2023 May 13:1-6. doi: 10.1080/00016357.2023.2205934. Online ahead of print.

ABSTRACT

INTRODUCTION: The present randomized split-mouth study aimed to investigate the clinical effectiveness of postoperative discomfort of the use of a surgical drain after lower third molar extraction.

MATERIALS AND METHODS: It was conducted a prospective randomized split-mouth study involving 30 patients with bilateral symmetric lower third molar. Each patient underwent two operations for the extraction of impacted teeth: test site (tube drain) and control site (conventional total closure of surgical flap), resulting in 30 cases in the test group, and 30 cases in the control group.Pain, swelling, and mouth opening were evaluated immediately before the surgeries, after 1, 3 and 7 days postoperatively in both groups. Data were analyzed with non-parametric test (Kruskal-Wallis test and the post hoc Dun test, and Wilcoxon matched-pairs signed rank test).

RESULTS: Facial swelling (p < .001) was significantly less in test group compared with the control group on all examined days. Trismus is significantly reduced only on the third day (p < .001); Pain measurements did not differ statistically significantly between the two groups on all post-operative days (p > .05).

CONCLUSION: The use of the tube drain reduced facial swelling and trismus, but had no influence on the subjective perception of postoperative pain.

PMID:37177802 | DOI:10.1080/00016357.2023.2205934

Sensors (Basel). 2023 May 7;23(9):4543. doi: 10.3390/s23094543.

ABSTRACT

The paper was devoted to the application of saliency analysis methods in the performance analysis of deep neural networks used for the binary classification of brain tumours. We have presented the basic issues related to deep learning techniques. A significant challenge in using deep learning methods is the ability to explain the decision-making process of the network. To ensure accurate results, the deep network being used must undergo extensive training to produce high-quality predictions. There are various network architectures that differ in their properties and number of parameters. Consequently, an intriguing question is how these different networks arrive at similar or distinct decisions based on the same set of prerequisites. Therefore, three widely used deep convolutional networks have been discussed, such as VGG16, ResNet50 and EfficientNetB7, which were used as backbone models. We have customized the output layer of these pre-trained models with a softmax layer. In addition, an additional network has been described that was used to assess the saliency areas obtained. For each of the above networks, many tests have been performed using key metrics, including statistical evaluation of the impact of class activation mapping (CAM) and gradient-weighted class activation mapping (Grad-CAM) on network performance on a publicly available dataset of brain tumour X-ray images.

PMID:37177747 | DOI:10.3390/s23094543

Sensors (Basel). 2023 May 6;23(9):4522. doi: 10.3390/s23094522.

ABSTRACT

This work relates to the quality of the electrocardiogram (ECG) signal of an elderly person, transmitted using optical wireless links. The studied system uses infrared signals between an optical transmitter located on the person’s wrist and optical receivers placed on the ceiling. As the elderly person moves inside a room, the optical channel is time-varying, affecting the received ECG signal. To assess the ECG quality, we use specific signal quality indexes (SQIs), allowing the evaluation of the spectral and statistical characteristics of the signal. Our main contribution is studying how the SQIs behave according to the optical transmission performance and the studied context in order to determine the conditions required to obtain excellent quality indexes. The approach is based on the simulation of the whole chain, from the raw ECG to the extraction process after transmission until the evaluation of SQIs. This technique was developed considering optical channel modeling, including the mobility of the elderly. The obtained results show the potential of optical wireless communication technologies for reliable ECG monitoring in such a context. It has been observed that excellent ECG quality can be obtained with a minimum SNR of 11 dB for on-off keying modulation.

PMID:37177726 | DOI:10.3390/s23094522

Sensors (Basel). 2023 May 6;23(9):4518. doi: 10.3390/s23094518.

ABSTRACT

The relentless expansion of communications services and applications in 5G networks and their further projected growth bring the challenge of necessary spectrum scarcity, a challenge which might be overcome using the concept of cognitive radio. Furthermore, an extremely high number of low-power devices are introduced by the concept of the Internet of Things (IoT), which also requires efficient energy usage and practically applicable device powering. Motivated by these facts, in this paper, we analyze a wirelessly powered underlay cognitive system based on a realistic case in which statistical channel state information (CSI) is available. In the system considered, the primary and the cognitive networks share the same spectrum band under the constraint of an interference threshold and a maximal tolerable outage permitted by the primary user. To adopt the system model in realistic IoT application scenarios in which network nodes are mobile, we consider the randomly moving cognitive user receiver. For the analyzed system, we derive the closed-form expressions for the outage probability, the outage capacity, and the ergodic capacity. The obtained analytical results are corroborated by an independent simulation method.

PMID:37177722 | DOI:10.3390/s23094518

Sensors (Basel). 2023 May 5;23(9):4504. doi: 10.3390/s23094504.

ABSTRACT

The present manuscript introduces an investigation of the structural and functional changes in the optic nerve in patients undergoing glaucoma treatment by comparing optical coherence tomography (OCT) measurements and RETeval system parameters. For such a purpose, 140 eyes were examined at the Ophthalmology Clinic of the “Elpis” General Hospital of Athens between October 2022 and April 2023. A total of 59 out of 140 eyes were from patients with early glaucoma under treatment (case group), 63 were healthy eyes (control group) and 18 were excluded. The experimental measurements were statistically analyzed using the SPSS software package. The main outcomes are summarized below: (i) there was no statistical difference between the right and left eye for both groups, (ii) statistical differences were found between age interval subgroups (30-54 and 55-80 years old) for the control group, mainly for the time response part of the RETeval parameters. Such difference was not indicated by the OCT system, and (iii) a statistical difference occurred between the control and case group for both OCT (through the retinal nerve fiber layer-RNFL thickness) and the RETeval parameters (through the photopic negative response-PhNR). RNFL was found to be correlated to b-wave (ms) and W-ratio parameters. In conclusion, the PhNR obtained by the RETeval system could be a valuable supplementary tool for the objective examination of patients with early glaucoma.

PMID:37177707 | DOI:10.3390/s23094504