Category: Statistics

Clin Anat. 2021 Apr 27. doi: 10.1002/ca.23742. Online ahead of print.

ABSTRACT

Ultrasound-guided regional anesthesia involves visualizing sono-anatomy to guide needle insertion and the perineural injection of local anesthetic. Anatomical knowledge, and recognition of anatomical structures on ultrasound, is known to be imperfect amongst anesthesiologists. This investigation evaluates the performance of an assistive artificial intelligence (AI) system in aiding the identification of anatomical structures on ultrasound. Three independent experts in regional anesthesia reviewed 40 ultrasound scans of seven body regions. Unmodified ultrasound videos were presented side-by-side with AI-highlighted ultrasound videos. Experts rated the overall system performance, ascertained whether highlighting helped identify specific anatomical structures, and provided opinion on whether it would help confirm the correct ultrasound view to a less experienced practitioner. Two hundred and seventy-five assessments were performed (five videos contained inadequate views); mean highlighting scores ranged from 7.87-8.69 (out of 10). The Kruskal-Wallis H-test showed a statistically significant difference in the overall performance rating (χ² [6] = 36.719, asymptotic p < 0.001); regions containing a prominent vascular landmark ranked most highly. AI-highlighting was helpful in identifying specific anatomical structures in 1330/1334 cases (99.7%) and for confirming the correct ultrasound view in 273/275 scans (99.3%). These data demonstrate the clinical utility of an assistive AI system in aiding the identification of anatomical structures on ultrasound during ultrasound-guided regional anesthesia. Whilst further evaluation must follow, such technology may present an opportunity to enhance clinical practice and energize the important field of clinical anatomy amongst clinicians.

PMID:33904628 | DOI:10.1002/ca.23742

Bioinformatics. 2021 Apr 27:btab248. doi: 10.1093/bioinformatics/btab248. Online ahead of print.

ABSTRACT

 : Biclustering is a generalization of clustering used to identify simultaneous grouping patterns in observations (rows) and features (columns) of a data matrix. Recently, the biclustering task has been formulated as a convex optimization problem. While this convex recasting of the problem has attractive properties, existing algorithms do not scale well. To address this problem and make convex biclustering a practical tool for analyzing larger data, we propose an implementation of fast convex biclustering called COBRAC to reduce the computing time by iteratively compressing problem size along the solution path. We apply COBRAC to several gene expression datasets to demonstrate its effectiveness and efficiency. Besides the standalone version for COBRAC, we also developed a related online web server for online calculation and visualization of the downloadable interactive results.

AVAILABILITY: The source code and test data are available at https://github.com/haidyi/cvxbiclustr or https://zenodo.org/record/4620218. The web server is available at https://cvxbiclustr.ericchi.com.

SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

PMID:33904580 | DOI:10.1093/bioinformatics/btab248

Neurology. 2021 Apr 26:10.1212/WNL.0000000000012050. doi: 10.1212/WNL.0000000000012050. Online ahead of print.

ABSTRACT

OBJECTIVE: To critically assess the clinical utility of striational antibodies (StrAbs) within paraneoplastic and myasthenia gravis serological evaluations.

METHODS: All Mayo Clinic patients tested for StrAbs from January 1^st 2012-December 31^st 2018 utilizing Mayo’s Unified Data Platform (UDP) were reviewed for neurological diagnosis and cancer.

RESULTS: 38,502 unique paraneoplastic and 1,899 MG patients were tested. In paraneoplastic evaluations, the StrAbs positivity rate was higher in cancer vs without cancer (5% [321/6775] vs 4% [1154/31727]; p<0.0001; OR 1.35; CI=1.19-1.53) but ROC analysis indicated no diagnostic accuracy in cancer (AUC=0.505). No neurological phenotype was significantly associated with StrAbs in the paraneoplastic group. Positivity was more common in all MG cancers compared to paraneoplastic cancers (p<0.0001). In MG evaluations, the StrAbs positivity rate was higher in those with cancer vs without (46% [217/474] vs 26% [372/1425]; p<0.0001; OR 2.39, CI 1.9-2.96) with ROC analysis indicating poor diagnostic accuracy for thymic cancer (AUC 0.634, recommended cutoff=1:60, sensitivity=56%, specificity=71%), with worse accuracy for extrathymic cancers (AUC 0.543). In paraneoplastic or MG evaluations, the value of antibody positivity did not improve cancer predictions. Paraneoplastic evaluated patients were more likely with positive StrAbs to obtain computed tomography (CT) (p=0.0001) with 3% (12/468) cancer found.

CONCLUSION: Despite a statistically significant association with cancer, an expansive review of performance in clinical service demonstrates that StrAbs are neither specific nor sensitive in predicting malignancy or neurological phenotypes. CT imaging is over utilized with positive StrAbs results. Removal of StrAbs from paraneoplastic or MG evaluations will improve the diagnostic characteristics of the current MG test.

CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that the presence of StrAbs do not accurately identify patients with malignancy or neurological phenotypes.

PMID:33903199 | DOI:10.1212/WNL.0000000000012050

Proc Natl Acad Sci U S A. 2021 May 4;118(18):e2025341118. doi: 10.1073/pnas.2025341118.

ABSTRACT

Understanding in a unified manner the generic and chemically specific aspects of activated dynamics in diverse glass-forming liquids over 14 or more decades in time is a grand challenge in condensed matter physics, physical chemistry, and materials science and engineering. Large families of conceptually distinct models have postulated a causal connection with qualitatively different “order parameters” including various measures of structure, free volume, thermodynamic properties, short or intermediate time dynamics, and mechanical properties. Construction of a predictive theory that covers both the noncooperative and cooperative activated relaxation regimes remains elusive. Here, we test using solely experimental data a recent microscopic dynamical theory prediction that although activated relaxation is a spatially coupled local-nonlocal event with barriers quantified by local pair structure, it can also be understood based on the dimensionless compressibility via an equilibrium statistical mechanics connection between thermodynamics and structure. This prediction is found to be consistent with observations on diverse fragile molecular liquids under isobaric and isochoric conditions and provides a different conceptual view of the global relaxation map. As a corollary, a theoretical basis is established for the structural relaxation time scale growing exponentially with inverse temperature to a high power, consistent with experiments in the deeply supercooled regime. A criterion for the irrelevance of collective elasticity effects is deduced and shown to be consistent with viscous flow in low-fragility inorganic network-forming melts. Finally, implications for relaxation in the equilibrated deep glass state are briefly considered.

PMID:33903245 | DOI:10.1073/pnas.2025341118

Stroke Vasc Neurol. 2021 Apr 26:svn-2020-000538. doi: 10.1136/svn-2020-000538. Online ahead of print.

ABSTRACT

BACKGROUND: To evaluate the association between coexisting intracranial and extracranial carotid artery atherosclerotic diseases and ipsilateral acute cerebral infarct (ACI) in symptomatic patients by using magnetic resonance (MR) vessel wall imaging.

METHODS: Symptomatic patients were recruited from a cross-sectional, multicentre study of Chinese Atherosclerosis Risk Evaluation (CARE-II). All patients underwent MR imaging for extracranial carotid arterial wall, intracranial artery and brain. Coexisting intracranial stenosis ≥50% and extracranial carotid artery mean wall thickness (MWT) ≥1 mm and plaque compositions at the same side were evaluated and the ipsilateral ACI was identified. The association between coexisting atherosclerotic diseases and ACI was evaluated using logistic regression.

RESULTS: 351 patients were recruited. Patients with ipsilateral ACI had significantly greater prevalence of coexisting intracranial stenosis ≥50% and carotid MWT ≥1 mm (20.5% vs 4.9%, p<0.001), calcification (15.1% vs 4.4%, p=0.001) and lipid-rich necrotic core (LRNC) (19.2% vs 7.8%, p=0.002) compared with those without. Coexisting intracranial artery stenosis ≥50% and carotid MWT ≥1 mm (OR 5.043, 95% CI 2.378 to 10.694; p<0.001), calcification (OR 3.864, 95% CI 1.723 to 8.664; p=0.001) and LRNC (OR 2.803, 95% CI 1.455 to 5.401; p=0.002) were significantly associated with ipsilateral ACI. After adjusting for confounding factors, the aforementioned associations remained statistically significant (intracranial stenosis ≥50% coexisting with carotid MWT ≥1 mm: OR 4.313, 95% CI 1.937 to 9.601, p<0.001; calcification: OR 3.606, 95% CI 1.513 to 8.593, p=0.004; LRNC: OR 2.358, 95% CI 1.166 to 4.769, p=0.017).

CONCLUSIONS: Coexistence of intracranial artery severe stenosis and extracranial carotid artery large burden and intraplaque components of calcification and LRNC are independently associated with ipsilateral ACI.

TRIAL REGISTRATION NUMBER: https://www.clinicaltrials.gov/. Unique identifier: NCT02017756.

PMID:33903178 | DOI:10.1136/svn-2020-000538

Neurology. 2021 Apr 26:10.1212/WNL.0000000000012074. doi: 10.1212/WNL.0000000000012074. Online ahead of print.

ABSTRACT

OBJECTIVE: To explore the occurrence of diseases and symptoms in the five years prior to diagnosis in patients with multiple sclerosis (MS) in a case-control study.

METHODS: Using ambulatory claims data we systematically assessed differences in the occurrence of diseases and symptoms in the five years prior to first diagnosis in patients with MS (n=10,262) as compared to patients with two other autoimmune diseases – Crohn’s disease (n=15,502) and psoriasis (n=98,432) – and individuals without these diseases (n=73,430).

RESULTS: Forty-three ICD-10 codes were recorded more frequently for patients with MS before diagnosis as compared to controls without autoimmune disease. Many of these findings were confirmed in a comparison to the other control groups. A high proportion of these ICD-10 codes represent symptoms suggestive of demyelinating events or other neurological diagnoses. In a sensitivity analysis excluding patients with such recordings prior to first diagnosis, no association remained significant. Seven ICD-10 codes were associated with lower odds ratios of MS, four of which represented upper respiratory tract infections. Here, the relations with MS were even more pronounced in the sensitivity analysis.

CONCLUSIONS: Our analyses suggest that patients with MS are frequently not diagnosed at their first demyelinating event but often years later. Symptoms and physician encounters before MS diagnosis seem to be related to already ongoing disease rather than a prodrome. The observed association of upper respiratory tract infections with lower ORs of MS diagnosis suggests a link between protection from infection and MS that however needs to be validated and further investigated.

PMID:33903190 | DOI:10.1212/WNL.0000000000012074

Diagn Interv Imaging. 2021 Apr 23:S2211-5684(21)00083-8. doi: 10.1016/j.diii.2021.03.005. Online ahead of print.

ABSTRACT

PURPOSE: The purpose of this study was to test the hypothesis that Jaccoud arthropathy (JA) in patients with systemic lupus erythematosus (SLE) is associated with instability of the extensor digitorum (ED) tendons during flexion of the metacarpophalangeal (MCP) joints by comparing the position of the ED tendons between SLE patients with JA and control subjects on hand MRI obtained with flexed and extended MCP joints.

MATERIALS AND METHODS: Thirty-two hands of SLE patients with JA (13 women and 3 men; mean age, 50.0±12.2 [SD] years; age range: 26-68years) and 24 hands of sex- and age-matched control subjects (20 women and 4 men; mean age, 50.1±13.0 [SD] years; age range: 24-68years) were included in the study. Axial spin echo T1-weighted MRI images of the second to fifth MCP joints in flexion and in extension were obtained. Two radiologists (R1 and R2) separately measured the amplitude and assessed the direction of the displacement of the ED tendons with respect to the midline at the level of each MCP joint. Statistical analysis included two-way ANOVA with random effects to assess differences in amplitude and Fisher-Freeman-Halton exact test to assess differences in direction with P-values<0.0083 and<0.0063 considered as statistically significant respectively.

RESULTS: Amplitude of the displacement of the ED tendons was statistically significantly greater in SLE patients with JA than in control subjects in flexion for both readers (median 58°, 95% confidence interval [CI]: 50°-65° vs. 20°, 95% CI: 16°-24°; P<0.0001 for R1 and 54°, 95% CI: 47°-61° vs. 25°, 95% CI: 22°-28°; P<0.0001 for R2) and in extension for one reader (17°, 95% CI: 15°-20° vs. 14°, 95% CI: 11°-16°; P=0.0048 for R1 and 20°, 95% CI: 15°-25° vs. 16°, 95% CI: 12°-18°; P=0.0292 for R2). Ulnar deviation of the ED tendons was statistically significantly more frequent in SLE patients with JA than in control subjects in flexion and in extension for both readers (P<0.0001).

CONCLUSION: JA is associated with instability of the ED tendons in patients with SLE best depicted when MCP joints are flexed.

PMID:33903055 | DOI:10.1016/j.diii.2021.03.005

BMJ Open. 2021 Apr 26;11(4):e043657. doi: 10.1136/bmjopen-2020-043657.

ABSTRACT

OBJECTIVE: Compelling evidence suggests that childhood adversities are associated with an increased risk of hypertension in middle age and old age. The link between childhood adversities and blood pressure in youth is less clear. In this cohort study, we examined the association between death of a parent during childhood and blood pressure in early adulthood in men.

SETTING: Sweden.

PARTICIPANTS: We studied 48 624 men born in 1949-1951 who participated in the compulsory military conscription in 1969/1970 in Sweden. Information on death of a parent during childhood was obtained from population-based registers. Information on covariates was obtained from the questionnaire and the clinical examination completed at conscription and from population-based registers.

OUTCOME MEASURES: Blood pressure was measured at conscription according to standard procedures.

RESULTS: The multivariable least square means of systolic and diastolic blood pressure did not differ between bereaved (128.25 (127.04-129.46) and 73.86 (72.89-74.84) mm Hg) and non-bereaved study participants (128.02 (126.86-129.18) and 73.99 (73.06-74.93) mm Hg). Results were similar when considering the cause of the parent’s death, the gender of the deceased parent or the child’s age at loss. Loss of a parent in childhood tended to be associated with an increased hypertension risk (OR and 95% CI: 1.10 (1 to 1.20)); the association was present only in case of natural deaths.

CONCLUSION: We found no strong support for the hypothesis that stress following the loss of a parent during childhood is associated with blood pressure or hypertension in youth in men.

PMID:33903141 | DOI:10.1136/bmjopen-2020-043657

Eur J Hosp Pharm. 2021 Apr 26:ejhpharm-2021-002793. doi: 10.1136/ejhpharm-2021-002793. Online ahead of print.

ABSTRACT

BACKGROUND: The literature regarding the seasonal variation in the therapeutic response to warfarin is somewhat contradictory, with several discrepancies. We assessed the influence of seasons on various pharmacodynamic indices of warfarin.

METHODS: A retrospective study was carried out in adults receiving warfarin for at least 6 months. Details of their demographic characteristics, duration and dose of warfarin therapy and values of prothrombin time international normalised ratio (PT-INR) were retrieved. Standard definitions were followed for defining various seasons, time in therapeutic range (TTR), log-INR variability and warfarin sensitivity index (WSI). National Institute for Health and Care Excellence (NICE) criteria were used for defining TTR into good (≥65%) and poor (<65%) anticoagulation control.

RESULTS: Two hundred and four patients were recruited. Only a subtle statistically significant difference was observed between the numbers of patients in the various PT-INR categories. However, no significant intra-individual differences were observed in mean TTR. Similarly, the proportion of patients with poor anticoagulation control, high INR variability and high WSI was not significantly different between summer, transition period 1, winter and transition period 2.

CONCLUSION: No clinically significant seasonal variations were observed in the therapeutic response to warfarin.

PMID:33903173 | DOI:10.1136/ejhpharm-2021-002793

Surgeon. 2021 Apr 24:S1479-666X(21)00067-6. doi: 10.1016/j.surge.2021.02.015. Online ahead of print.

ABSTRACT

INTRODUCTION: Twenty-five-hydroxy-vitamin D3 (25-OH-vit D) is a prohormone that is essential for normal calcium homeostasis and bone metabolism. Understanding its role is an important component of the proper care of the pediatric orthopaedic patient. The aim of this study was to determine whether children in Ireland with fractures have increased prevalence of 25-OH-Vit D deficiency compared with age matched controls and to ascertain the relationship between a low 25-OH-vit D level and the incidence of fractures in Irish children. We hypothesised that children presenting to our centre following a fracture would have significantly lower 25-OH-vit D.

METHODS: A prospective case-control study at a large urban tertiary referral academic hospital located in Dublin, Ireland was completed over a 14 month period from June 2014 to August 2015. A total of 116 subjects, distributed as cases (n = 58) and controls (n = 58) were included in this study. Whole blood (10 ml) was taken in two serum bottles from each patient. Serum 25-hydroxy-vitamin D3 levels were measured. An age matched control group was generated from other children attending the hospital, who also had vitamin D levels measured for different clinical reasons. We followed up both the fracture and control group for the next 5 years to assess the repeat fracture rate.

RESULTS: Fifty-eight patients with a fracture requiring operative intervention, were included in the study. Statistical analysis was performed comparing to 58 age and sex-matched controls. The mean vitamin D level for the fracture group was 63.2 nmol/L (SD = 27.3), which was higher than the mean of the controls (62.5 nmol/L) (SD = 21.3) (p = 0.86), but this difference was found not to be statistically significant in unadjusted analysis. There was no statistically significant difference in the number of patients classified with low serum Vitamin D levels (<50 nmolL), with the fracture group consisting of 22 (37.9%) patients, and the control group of 17 patients (29.3%) (p = 0.33) with a level below 50 nmol/L. At five-year follow-up, 11 of the 58 patients (18.9%) in the fracture group went on to have a further fracture compared with eight patients (13.7%) from the control group. Out of these 11 from the fracture group five (45.45%) had been found to have a low serum 25-OH-Vit D level five years previously. Out of the eight controls that presented with a fracture within the five-year period, 3 (37.5%) had had a low vitamin D level at the origin of this study.

CONCLUSION: The results of this study show that children presenting to our institution with low energy fractures have a prevalence of 38% 25-hydroxy-vitamin D deficiency. This study included children from age 1 to 16 primarily Caucasian encompassing all fracture types resulting from accidental trauma. Our findings suggest that in an Irish pediatric population vitamin D status may impact fracture risk with more than one-third being deficient in this review.

PMID:33903053 | DOI:10.1016/j.surge.2021.02.015