Category: Statistics

J Neuroeng Rehabil. 2021 Dec 28;18(1):184. doi: 10.1186/s12984-021-00977-2.

ABSTRACT

BACKGROUND: A client-centred task-oriented approach has advantages towards motivation and adherence to therapy in neurorehabilitation, but it is costly to integrate in practice. An intelligent Activity-based Client-centred Training (i-ACT), a low-cost Kinect-based system, was developed which integrates a client-centred and task-oriented approach. The objectives were (1) to investigate the effect of additional i-ACT training on functioning. And (2) to assess whether training with i-ACT resulted in more goal oriented training.

METHODS: A single-blind randomised controlled trial was performed in 4 Belgian rehabilitation centres with persons with central nervous system deficits. Participants were randomly allocated through an independent website-based code generator using blocked randomisation (n = 4) to an intervention or control group. The intervention group received conventional care and additional training with i-ACT for 3 × 45 min/week during 6 weeks. The control group received solely conventional care. Functional ability and performance, quality of life (QoL), fatigue, trunk movement, and shoulder active range of motion (AROM) were assessed at baseline, after 3 weeks and 6 weeks of training, and 6 weeks after cessation of training. Data were analysed using non-parametric within and between group analysis.

RESULTS: 47 persons were randomised and 45 analysed. Both intervention (n = 25) and control (n = 22) group improved over time on functional ability and performance as measured by the Wolf Motor Function Test, Manual Ability Measure-36, and Canadian Occupational Performance Measure, but no major differences were found between the groups on these primary outcome measures. Regarding QoL, fatigue, trunk movement, and shoulder AROM, no significant between group differences were found. High adherence for i-ACT training was found (i.e. 97.92%) and no adverse events, linked to i-ACT, were reported. In the intervention group the amount of trained personal goals (88%) was much higher than in the control group (46%).

CONCLUSIONS: Although additional use of i-ACT did not have a statistically significant added value regarding functional outcome over conventional therapy, additional i-ACT training provides more individualised client-centred therapy, and adherence towards i-ACT training is high. A higher intensity of i-ACT training may increase therapy effects, and should be investigated in future research.

TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT02982811. Registered 29 November 2016.

PMID:34961531 | DOI:10.1186/s12984-021-00977-2

J Neuroimaging. 2021 Dec 27. doi: 10.1111/jon.12961. Online ahead of print.

ABSTRACT

BACKGROUND AND PURPOSE: Stent retriever (SR) thrombectomy is commonly used for the treatment of emergent large vessel occlusion (ELVO) in acute ischemic stroke. Clot imaging parameters such as clot length, diameter, distance to the internal carotid artery terminus, and vessel angle where the SR is deployed may predict the likelihood of achieving first pass effect (FPE). Most of the proposed factors that seem to affect recanalization success have been studied individually, and conflicting data derived from clinical versus in vitro studies using 3-dimensional printed models of intracranial circulation currently exist.

METHODS: Using patient-specific 3-dimensional phantoms of the cervical and intracranial circulation, we simulated middle cerebral arteries (MCA) M1 and M2 occlusions treated with SR thrombectomy using Solitaire (Medtronic) or Trevo (Styker). Our primary outcome was FPE, defined as Thrombolysis in Cerebral Infarction score of 2c-3 achieved after a single thrombectomy attempt. We also performed retrospective analysis of same clot imaging characteristics of consecutive cases of MCA occlusion and its association with FPE matching the 3-dimensional in vitro experiments. Analysis was conducted using IBM SPSS Statistics Version 25 (IBM Corp., Armonk, NY). Chi-square tests and bivariate logistic regressions were the main statistical tests used in analysis. A p-value of less than .05 was considered to indicate statistical significance. Ninety-five confidence intervals (95% CI) were generated.

RESULTS: We compared 41 thrombectomy experiments performed using patient-specific 3-dimensional in vitro models with a retrospective cohort of 41 patients treated with SR thrombectomy. We found that in the in vitro cohort, higher MCA angulation was associated with a lower likelihood of FPE (odds ratio [OR] = 0.967, 95% CI = 0.944-0.991, p = .008). Meanwhile in the in vivo cohort, higher MCA angulation was associated with a higher likelihood of FPE (OR = 1.039, 95% CI = 1.003-1.077, p = .033). Neither clot length nor location of clot (M1 vs. M2) was associated with a difference in FPE rates in either cohort.

DISCUSSION: Comparison of SR thrombectomy performed during actual MCA occlusion cases versus patient-specific 3-dimensional replicas revealed MCA angulation as an independent predictor of procedure success or failure. However, the opposite direction of effect was observed between the two studied environments, indicating potential limitations of studying SR thrombectomy using 3-dimensional models of LVO.

PMID:34958701 | DOI:10.1111/jon.12961

Brief Bioinform. 2021 Dec 28:bbab528. doi: 10.1093/bib/bbab528. Online ahead of print.

ABSTRACT

Batch effects explain a large part of the noise when merging gene expression data. Removing irrelevant variations introduced by batch effects plays an important role in gene expression studies. To obtain reliable differential analysis results, it is necessary to remove the variation caused by technical conditions between different batches while preserving biological variation. Usually, merging data directly with batch effects leads to a sharp rise in false positives. Although some methods of batch correction have been developed, they have some drawbacks. In this study, we develop a new algorithm, adjustment mean distribution-based normalization (AMDBNorm), which is based on a probability distribution to correct batch effects while preserving biological variation. AMDBNorm solves the defects of the existing batch correction methods. We compared several popular methods of batch correction with AMDBNorm using two real gene expression datasets with batch effects and analyzed the results of batch correction from the visual and quantitative perspectives. To ensure the biological variation was well protected, the effects of the batch correction methods were verified by hierarchical cluster analysis. The results showed that the AMDBNorm algorithm could remove batch effects of gene expression data effectively and retain more biological variation than other methods. Our approach provides the researchers with reliable data support in the study of differential gene expression analysis and prognostic biomarker selection.

PMID:34958674 | DOI:10.1093/bib/bbab528

Magn Reson Med. 2021 Dec 27. doi: 10.1002/mrm.29125. Online ahead of print.

ABSTRACT

PURPOSE: Multicomponent analysis of MRI T₂ relaxation time (mcT₂ ) is commonly used for estimating myelin content by separating the signal at each voxel into its underlying distribution of T₂ values. This voxel-based approach is challenging due to the large ambiguity in the multi-T₂ space and the low SNR of MRI signals. Herein, we present a data-driven mcT₂ analysis, which utilizes the statistical strength of identifying spatially global mcT₂ motifs in white matter segments before deconvolving the local signal at each voxel.

METHODS: Deconvolution is done using a tailored optimization scheme, which incorporates the global mcT₂ motifs without additional prior assumptions regarding the number of microscopic components. The end results of this process are voxel-wise myelin water fraction maps.

RESULTS: Validations are shown for computer-generated signals, uniquely designed subvoxel mcT₂ phantoms, and in vivo human brain. Results demonstrated excellent fitting accuracy, both for the numerical and the physical mcT₂ phantoms, exhibiting excellent agreement between calculated myelin water fraction and ground truth. Proof-of-concept in vivo validation is done by calculating myelin water fraction maps for white matter segments of the human brain. Interscan stability of myelin water fraction values was also estimated, showing good correlation between scans.

CONCLUSION: We conclude that studying global tissue motifs prior to performing voxel-wise mcT₂ analysis stabilizes the optimization scheme and efficiently overcomes the ambiguity in the T₂ space. This new approach can improve myelin water imaging and the investigation of microstructural compartmentation in general.

PMID:34958690 | DOI:10.1002/mrm.29125

J Biopharm Stat. 2021 Dec 27:1-17. doi: 10.1080/10543406.2021.2011902. Online ahead of print.

ABSTRACT

In this paper, we develop a methodology for leveraging real-world data into single-arm clinical trial studies. In recent years, the idea of augmenting randomized clinical trials data with real-world data has emerged as a particularly attractive technique for health organizations and drug developers to accelerate the drug development process. Major regulatory authorities such as the Food and Drug Administration and European Medicines Agency have recognized the potential of utilizing real-world data and are advancing toward making regulatory decisions based on real-world evidence. Several statistical methods have been developed in recent years for borrowing data from real-world sources such as electronic health records, product and disease registries, as well as claims and billing data. We propose a novel approach to augment single-arm clinical trials with the real-world data derived from single or multiple data sources. Furthermore, we illustrate the proposed method in the presence of missing data and conduct simulation studies to evaluate its performance in diverse settings.

PMID:34958629 | DOI:10.1080/10543406.2021.2011902

J Speech Lang Hear Res. 2021 Dec 27:1-14. doi: 10.1044/2021_JSLHR-21-00306. Online ahead of print.

ABSTRACT

PURPOSE: We proposed and tested a causal instantiation of the World Health Organization’s International Classification of Functioning, Disability and Health (ICF) framework, linking acoustics, intelligibility, and communicative participation in the context of dysarthria.

METHOD: Speech samples and communicative participation scores were collected from individuals with dysarthria (n = 32). Speech was analyzed for two acoustic metrics (i.e., articulatory precision and speech rate), and an objective measure of intelligibility was generated from listener transcripts. Mediation analysis was used to evaluate pathways of effect between acoustics, intelligibility, and communicative participation.

RESULTS: We observed a strong relationship between articulatory precision and intelligibility and a moderate relationship between intelligibility and communicative participation. Collectively, data supported a significant relationship between articulatory precision and communicative participation, which was almost entirely mediated through intelligibility. These relationships were not significant when speech rate was specified as the acoustic variable of interest.

CONCLUSION: The statistical corroboration of our causal instantiation of the ICF framework with articulatory acoustics affords important support toward the development of a comprehensive causal framework to understand and, ultimately, address restricted communicative participation in dysarthria.

PMID:34958608 | DOI:10.1044/2021_JSLHR-21-00306

Vascular. 2021 Dec 27:17085381211062747. doi: 10.1177/17085381211062747. Online ahead of print.

ABSTRACT

OBJECTIVES: Thoracic outlet syndrome (TOS) is a group of disorders caused by impingement of the neurovascular structures at the thoracic outlet. Neurogenic TOS (nTOS), which is thought to be caused by a compression of the brachial plexus, accounts for more than 90% of the cases. Although treatment for nTOS is successful through physiotherapy and/or surgical decompression, little is known about the impact of psychosocial factors, namely, major depressive disorder (MDD), on postoperative outcomes such as non-routine discharge (NRD). Here, we assess whether MDD predicts the type of discharge following nTOS surgical intervention.

METHODS: A retrospective analysis of the National Inpatient Sample database from the years 2005-2018 was performed. Using the International Classification of Diseases Clinical Modification, Ninth and Tenth revisions, patients who underwent a surgical intervention for nTOS were identified. Our primary outcome was to investigate the effects of MDD on nTOS patient disposition status after surgical management; secondary outcomes included analysis of total hospital charges and length of stay. NRD was defined as anything beyond discharge home without healthcare services. Univariate and multivariable logistic regression analyses were conducted to assess MDD and other potential independent predictors of NRD and prolonged hospital stay (> 2 days) following surgical intervention.

RESULTS: A total of 6099 patients were identified: 596 (9.77%) patients with MDD and 5503 (90.23%) without MDD. On average, patients with MDD were older (39.6 ± 12.0 years vs. 36.0 ± 13.0 years; p < 0.001), female (80.7% vs. 63.5%; p < 0.001), white (89.6% vs. 85.6%; p = 0.030), and on Medicare (9.6% vs 5.2%; p < 0.001). Univariate and multivariable logistic regression models identified MDD as an independent risk factor associated with a higher risk of NRD (adjusted odds ratio [aOR], 1.50; 95% confidence interval [CI], 1.0-2.2). Additionally, chronic kidney disease (aOR, 2.60; 95% CI, 1.2-5.4), postoperative complications (aOR, 1.87; 95% CI, 1.2-2.9), and Medicare (aOR, 2.95; 95% CI, 1.9-4.7) were statistically significant predictors for higher risk of NRD. However, MDD was not associated with prolonged hospital stay (aOR, 1.00; 95% CI, 0.8-1.2) or higher median of total charges (MDD group: $27,867 vs. non-MDD group: $28,123; p = 0.799).

CONCLUSION: Comorbid MDD was strongly associated with higher NRD rates following nTOS surgical intervention. MDD had no significant impact on length of hospital stay or total hospital charges. Additional prospective research is necessary in order to better evaluate the impact of MDD in patients with nTOS.

PMID:34958613 | DOI:10.1177/17085381211062747

Chin Med J (Engl). 2021 Dec 21. doi: 10.1097/CM9.0000000000001864. Online ahead of print.

ABSTRACT

BACKGROUND: Hepatectomy for hepatocellular carcinoma (HCC) beyond the Milan criteria is shown to be beneficial. However, a high rate of post-operative HCC recurrence hinders the long-term survival of the patients. This study aimed to investigate and compare the impacts of tenofovir (TDF) and entecavir (ETV) on the recurrence of hepatitis B viral (HBV)-related HCC beyond the Milan criteria.

METHODS: Data pertaining to 1532 patients who underwent hepatectomy and received antiviral therapy between January 2014 and January 2019 were collected from five centers. Recurrence-free survival (RFS) analysis was performed using the Kaplan-Meier method. Cox proportional hazards regression analysis was performed to determine prognostic factors for HCC recurrence.

RESULTS: The analysis incorporates 595 HBV-related HCC patients. The overall 5-year RFS was 21.3%. Among them, 533 and 62 patients received ETV and TDF treatment, respectively. The 1-, 3-, and 5-year RFS rates were 46.3%, 27.4%, and 19.6%, respectively, in the ETV group compared with 65.1%, 41.8%, and 37.2%, respectively, in the TDF group (P < 0.001). Multivariate analysis showed that TDF treatment (hazard ratio [HR]: 0.604, P = 0.005), cirrhosis (HR: 1.557, P = 0.004), tumor size (HR: 1.037, P = 0.008), microvascular invasion (MVI) (HR: 1.403, P = 0.002), portal vein tumor thrombus (PVTT) (HR: 1.358, P = 0.012), capsular invasion (HR: 1.228, P = 0.040), and creatinine levels (CREA) (HR: 0.993, P = 0.031) were statistically significant prognostic factors associated with RFS.

CONCLUSIONS: Patients with HCC beyond the Milan criteria exhibited a high rate of HCC recurrence after hepatectomy. Compared to the ETV therapy, TDF administration significantly lowered the risk of HCC recurrence.

PMID:34958539 | DOI:10.1097/CM9.0000000000001864

J Phys Chem Lett. 2021 Dec 27:91-97. doi: 10.1021/acs.jpclett.1c03813. Online ahead of print.

ABSTRACT

We apply chirped-pulse uniform flow millimeterwave (CPUF-mmW) spectroscopy to study the complex multichannel reaction dynamics in the reaction between the propargyl and amino radicals (C₃H₃ + NH₂/ND₂), a radical-radical reaction of importance in the gas-phase chemistry of astrochemical environments and combustion systems. The photolytically generated radicals are allowed to react in a well-characterized quasi-uniform supersonic flow, and mmW rotational spectroscopy (70-93 GHz) is used for simultaneous detection of the reaction products: HCN, HNC, HC₃N, DCN, DNC, and DC₃N, while spectral intensities of the measured pure-rotational lines allow product branching to be quantified. High-level electronic structure calculations were used for theoretical prediction of the reaction pathways and branching. Experimentally deduced product branching fractions were compared with the results from statistical simulations based on the RRKM theory. Product branching was found to be strongly dependent on the excess internal energy of the C₃H₃ and NH₂/ND₂ reactants.

PMID:34958581 | DOI:10.1021/acs.jpclett.1c03813

Int Endod J. 2021 Dec 27. doi: 10.1111/iej.13676. Online ahead of print.

ABSTRACT

AIM: To identify factors that are predictive of short-term professional and societal impact of research within the specialty of Endodontology, and to identify the top-10 articles that achieved the greatest societal impact and describe their characteristics.

METHODOLOGY: Research articles in the field of Endodontology published in 2019 were eligible for inclusion, with the sample identified using Medline. Following screening of titles and abstracts, bibliometric data of the identified articles were exported into a spreadsheet, where further data related to continental origin, type of article, type of journal (endodontic or non-endodontic) and grant-funding were collated, with additional data concerning presence of journal impact factor, citations, news mentions and Altmetric-tracked-mentions and scores compiled using Clarivate, Scopus, ProQuest and Altmetric Explorer, respectively. Data analysis comprised descriptive statistics, frequency distributions, cross-tabulations and un/adjusted negative binomial regression models (P<0.05).

RESULTS: The search retrieved 30,443 articles; 951 were included for analysis. Most articles originated from Asia (43.2%) with over 51.5% of articles published in endodontic journals and 80% published in a journal with an impact factor. Over three-quarters of articles were primary research, 141 were grant-funded, 165 had a news mention, 338 achieved an Altmetric Attention Score and 808 were cited. The five-highest ranked articles were mentioned in general news bulletins, five of the top-10 articles were primary research and six of the top-10 were published in endodontic journals. The highest Altmetric Attention Score and citation count were 100 and 87, respectively. Adjusted models demonstrated that the type of article, publication in a journal with an impact factor, absence of grant-funding and coverage within general news bulletins predicted the Altmetric Attention Scores (P<0.001). Article type, publication in an impact-factor journal and presence of an Altmetric Attention Score were predictive of citations (P<0.001).

CONCLUSIONS: Article type and publication in a journal with an impact factor were significant predictors of both societal and professional impact of research articles within Endodontology in the short-term. Non grant-funded research and coverage in general news bulletins achieved greater societal impact, whereas an article achieving an Altmetric Attention Score was also strongly related to professional impact.

PMID:34958490 | DOI:10.1111/iej.13676