Tag: statistics

PLoS Comput Biol. 2021 Mar 12;17(3):e1008515. doi: 10.1371/journal.pcbi.1008515. Online ahead of print.

ABSTRACT

Many ischaemic stroke patients who have a mechanical removal of their clot (thrombectomy) do not get reperfusion of tissue despite the thrombus being removed. One hypothesis for this ‘no-reperfusion’ phenomenon is micro-emboli fragmenting off the large clot during thrombectomy and occluding smaller blood vessels downstream of the clot location. This is impossible to observe in-vivo and so we here develop an in-silico model based on in-vitro experiments to model the effect of micro-emboli on brain tissue. Through in-vitro experiments we obtain, under a variety of clot consistencies and thrombectomy techniques, micro-emboli distributions post-thrombectomy. Blood flow through the microcirculation is modelled for statistically accurate voxels of brain microvasculature including penetrating arterioles and capillary beds. A novel micro-emboli algorithm, informed by the experimental data, is used to simulate the impact of micro-emboli successively entering the penetrating arterioles and the capillary bed. Scaled-up blood flow parameters-permeability and coupling coefficients-are calculated under various conditions. We find that capillary beds are more susceptible to occlusions than the penetrating arterioles with a 4x greater drop in permeability per volume of vessel occluded. Individual microvascular geometries determine robustness to micro-emboli. Hard clot fragmentation leads to larger micro-emboli and larger drops in blood flow for a given number of micro-emboli. Thrombectomy technique has a large impact on clot fragmentation and hence occlusions in the microvasculature. As such, in-silico modelling of mechanical thrombectomy predicts that clot specific factors, interventional technique, and microvascular geometry strongly influence reperfusion of the brain. Micro-emboli are likely contributory to the phenomenon of no-reperfusion following successful removal of a major clot.

PMID:33711015 | DOI:10.1371/journal.pcbi.1008515

J Craniomaxillofac Surg. 2021 Feb 23:S1010-5182(21)00070-6. doi: 10.1016/j.jcms.2021.02.013. Online ahead of print.

ABSTRACT

The aim of this study was to assess any change between the preoperative and postoperative sizes of temporal and masseter muscles with magnetic resonance imaging (MRI) in patients undergoing unilateral temporomandibular joint surgery. This study was designed and implemented retrospectively. For clinical evaluation, a visual analog scale (VAS) and maximum mouth opening (MMO) were used. In order to make a preoperative diagnosis and perform a 6-month control, muscle size was measured in millimeters (mm) on T1 axial sections in MRI. Statistical analyses were performed using the SPSS 23.0 software package. Numeric variables were compared between two dependent groups using the Wilcoxon signed rank test. Statistical significance was set at p < 0.05. Twelve patients who underwent unilateral discectomy plus dermis-fat grafting, with classical preauricular inverse L incision, were included in the study, and data for eleven female patients were evaluated. The difference in size between the operated and non-operated sides was found to be statistically insignificant at the preoperative stage for both masseter muscle (operated side m^M: 13.264 ± 1.822 mm; non-operated side m^M: 13.264 ± 2.315 mm; p^M = 0.929) and temporal muscle (operated side m^T: 20.345 ± 2.609 mm; non-operated side m^T: 20.582 ± 2.366 mm; p^T = 0.594). There was a significant size reduction in the masseter muscle on the operated side in the postoperative period (preop m^M: 13.264 ± 1.822 mm; postop m^M: 12.036 ± 1.728 mm; p^M = 0.018). Although there was also a size reduction in the operated side of the temporal muscle in the postoperative period, that difference did not reach statistical significance (preop m^T: 20.345 ± 2.609 mm; postop m^T: 19.445 ± 1.603 mm; p^T = 0.182). On the non-operated side, there were no significant postoperative changes in the sizes of either the masseter muscle (preop m^M: 13.264 ± 2.315 mm; postop m^M: 12.682 ± 2.059 mm; p^M = 0.248) or the temporal muscle (preop m^T: 20.582 ± 2.366; postop m^T: 19.891 ± 3.487 mm; p^T = 0.625). Considering the study findings as a whole, a size reduction was observed in the operated side of the masseter muscle after TMJ surgery. The etiology of this change may be surgical trauma to the temporal and masseter muscles, skeletal alteration resulting from condylar change secondary to discectomy, and patients restraining themselves from application of maximum bite force as a result of a self-protection mechanism due to postoperative pain.

PMID:33707133 | DOI:10.1016/j.jcms.2021.02.013

J Am Soc Cytopathol. 2021 Feb 22:S2213-2945(21)00026-0. doi: 10.1016/j.jasc.2021.02.003. Online ahead of print.

ABSTRACT

OBJECTIVE: The objective of this study was to investigate the feasibility of implementing videos captured by static telecytological applications for remote cytological diagnosis of fine needle aspiration (FNA) specimens from salivary gland lesions.

METHODS: The current study was performed on 102 specimens from patients referred to the Alpha Prolipsis Cytopathology Department for preoperative evaluation of salivary gland lesions. In all cases, surgical excision followed the initial cytological diagnosis. (benign lesions, 11; benign neoplasms, 68; malignant neoplasms, 23). Videos were transferred via file transfer protocol to password-protected accounts for remote review by three independent cytopathologists. In addition to diagnosis, reviewers commented on overall digital video quality. Contributor’s and reviewer’s diagnoses were collected, recorded and statistically evaluated.

RESULTS: Statistical evaluation of cytological diagnoses detected no significant difference in diagnostic accuracy between the diagnoses proffered on the basis of precaptured videos and conventional slides. The overall interobserver agreement was ranging from substantial to almost perfect with κ values of 0.71-0.89.

CONCLUSIONS: Videos production by static telecytology applications can be used as an alternative method for telecytological diagnosis of salivary glands FNAs. Videos of salivary glands FNAs can be used for accurate diagnosis, educational and second opinion purposes,. They can also be used for archiving, teleconsultation and educational purposes, improving the performance of the already existing static telecytology stations and small cytology departments’ quality indices.

PMID:33707150 | DOI:10.1016/j.jasc.2021.02.003

J Sci Med Sport. 2021 Mar 4:S1440-2440(21)00052-9. doi: 10.1016/j.jsams.2021.02.016. Online ahead of print.

ABSTRACT

OBJECTIVES: To assess the risk of lateral ankle sprain (LAS) in male and female tactical athletes across different military occupations in the US military.

DESIGN: Retrospective cohort.

METHODS: The Defense Medical Epidemiology Database was queried for the number of individuals with ICD-9 diagnosis codes 845.00 (sprain of ankle, unspecified) and 845.02 (calcaneofibular ligament sprain) on their initial encounter from 2006 to 2015. Relative risk (RR) and chi-square statistics were calculated assessing sex and occupational category on LAS risk.

RESULTS: 272,970 enlisted males (27.9 per 1000 person-years), 56,732 enlisted females (34.5 per 1000 person-years), 24,534 male officers (12.6 per 1000 person-years), and 6020 female officers (16.4 per 1000 person-years) incurred a LAS. Enlisted females in all occupational groups were at significantly higher risk for LAS than their male counterparts (RR 1.09-1.68; p<0.001), except for Engineers (p=0.15). Female officers had consistently higher risk for LAS in all occupational groups (RR 1.10-1.42; p<0.001) compared with male officers, except Ground/Naval Gunfire (p=0.23). Contrasted with Infantry, enlisted tactical athletes in the Special Operations Forces, Mechanized/Armor, Aviation, Maintenance, and Maritime/Naval Specialties were at lower risk (RR 0.38-0.93; p<0.001), Artillery, Engineers, and Logistics Specialties were at higher risk (RR 1.04-1.18; p<0.001), and Administration, Intelligence, and Communications were no different (p=0.69). Compared with Ground/Naval Gunfire officers, Aviation officers were at significantly lower risk (RR, 0.75; p<0.001), and Engineers, Maintenance, Administration, Operations/Intelligence, and Logistics officers were at higher risk (RR, 1.08-1.20; p<0.001).

CONCLUSIONS: Sex and military occupation were salient factors associated with LAS risk.

PMID:33707156 | DOI:10.1016/j.jsams.2021.02.016

Sleep Med. 2021 Feb 9:S1389-9457(21)00052-6. doi: 10.1016/j.sleep.2021.01.035. Online ahead of print.

ABSTRACT

OBJECTIVE/BACKGROUND: The aim of this study was to examine the relationship between overnight consolidation of implicit statistical learning with spindle frequency EEG activity and slow frequency delta power during non-rapid eye movement (NREM) sleep in obstructive sleep apnea (OSA).

PATIENTS/METHODS: Forty-seven OSA participants completed the experiment. Prior to sleep, participants performed a reaction time cover task containing hidden patterns of pictures, about which participants were not informed. After the familiarisation phase, participants underwent overnight polysomnography. 24 h after the familiarisation phase, participants performed a test phase to assess their learning of the hidden patterns, expressed as a percentage of the number of correctly identified patterns. Spindle frequency activity (SFA) and delta power (0.5-4.5 Hz), were quantified from NREM electroencephalography. Associations between statistical learning and sleep EEG, and OSA severity measures were examined.

RESULTS: SFA in NREM sleep in frontal and central brain regions was positively correlated with statistical learning scores (r = 0.41 to 0.31, p = 0.006 to 0.044). In multiple regression, greater SFA and longer sleep onset latency were significant predictors of better statistical learning performance. Delta power and OSA severity were not significantly correlated with statistical learning.

CONCLUSIONS: These findings suggest spindle activity may serve as a marker of statistical learning capability in OSA. This work provides novel insight into how altered sleep physiology relates to consolidation of implicitly learnt information in patients with moderate to severe OSA.

PMID:33707093 | DOI:10.1016/j.sleep.2021.01.035

Arch Pediatr. 2021 Mar 8:S0929-693X(21)00024-5. doi: 10.1016/j.arcped.2020.12.013. Online ahead of print.

ABSTRACT

It is well established today that an optimal vitamin D intake plays a crucial role in the constitution of optimal osseous mass during childhood, and hence in the prevention of the osteoporosis in adults. The prevalence of the vitamin D deficiency is increasing globally and Algeria is no exception in this regard. Our study is the first to be carried out with healthy children of preschool age in North Africa.

AIMS: The study aimed to evaluate the vitamin D status of a pediatric population, during all four seasons of the year, living in the north of Algeria, as well as to estimate the prevalence of vitamin D deficiency, identifying the potential risk factors.

MATERIAL AND METHODS: This was an analytic and cross-sectional study carried out between March 2014 and March 2016 with healthy preschool infants from an urban environment in the town of Hussein Dey. A total of 1016 infants aged 9-72 months were included during this period. The consensual threshold value was 20ng/mL.

RESULTS: The sex ratio was of 1.47 (535 boys/481 girls) and the average age of the children was 36.5±1.79 months. The daily average calcium ratio was 395±23 mg/with food contributions in vitamin D at an estimated average of 164 UI/day (4.1μg/day). The average concentration of the total 25-OHD for all four seasons of the year was 18.6±10.4ng/mL with an average rate of parathyroid hormone (PTH) of 30.9±14.6pg/mL. There was a highly significant inverse correlation between the serum level of vitamin D and PTH (r=-0.57; P=0.0001), the point of inflection was situated at 34.1ng/mL. The prevalence of vitamin D deficiency follows a seasonal variation that is statistically significant (P=0.0001), and the prevalence is higher during the autumn-winter period. The risk factors identified by multiple logistic regression were autumn-winter season (OR: 7; 95% CI: 3-11; P=0.001), age less than 24 months (OR: 3.8; 95% CI: 3.4-4.4; P=0.0001), high body mass index (OR: 2; 95% CI: 1.2-3.2; P=0.3), darker skin pigmentation (OR: 2.8; 95% CI: 2.2-5.2; P=0.001), duration of sunlight exposure less than 15min (OR: 6.1; 95% CI: 3.6-10.2; P=0.0001), low socioeconomic status (OR: 3.9; 95% CI: 1.5-4.3; P=0.01), calcium intake lower than 500 mg/day (OR: 2.5; 95% CI: 1.8-6; P=0.001), and a weekly dietary intake of vitamin D lower than 200 UI (OR: 2.6; 95% CI: 1.6-4.2; P=0.02).

DISCUSSION: No studies have been conducted in north Africa or Algeria concerning healthy preschool children; however, this population has a rapid growth rate and deserves special attention. The prevalence of vitamin D deficiency in the children of this study was higher than that reported in studies of children of the same age living in Europe or America, despite the fact that Algeria is closer to the equator (36° latitude north).

CONCLUSION: The changes experienced by Algerian society and the shorter exposure of the population to the sun call for more efforts regarding the detection and treatment of vitamin D deficiency, as well as an update of the vitamin D supplementation schedule.

PMID:33707102 | DOI:10.1016/j.arcped.2020.12.013

J Med Imaging Radiat Sci. 2021 Mar 8:S1939-8654(21)00036-9. doi: 10.1016/j.jmir.2021.02.004. Online ahead of print.

ABSTRACT

PURPOSE: The purpose of this project was to assess factors that may influence variability in the pre-treatment kilovoltage cone beam computed tomography (kV CBCT) image matching process for lung stereotactic body radiation therapy (SBRT).

METHODS AND MATERIALS: Pre-treatment CBCT and planning CT data sets of previously-treated lung SBRT patients were gathered and anonymized from four radiotherapy centers in Alberta. Eight radiation therapists (RTTs) and four radiation oncologists (ROs) were recruited from the same four cancer centers for image matching. Identical data sets were provided to each user, but the order of image sets was randomized independently for each user to remove any learning bias. Inter-user variabilities were then investigated as functions of various factors, including image origin (source institution/machine), user’s institution (local matching protocol), profession (RTT vs. RO), years of experience and image quality (presence/absence of added noise).

RESULTS: Very little variation in image matching between different users was observed. The mean differences from the consensus means for different image sets were less than 1 mm in all directions, and cases that exceeded 3 mm (i.e. clinically significant differences) were extremely rare. Image origin, user’s institution, and profession (RTT vs. RO) didn’t lead to any meaningful clinical differences, while image quality didn’t introduce any statistically significant differences. In addition, no discernible trend was seen between user’s experience and deviation from the user mean. Overall, no meaningful differences in inter-user variabilities for the different factors investigated were found in this study.

CONCLUSIONS: There appears to be an adequate standardization across the province of Alberta in terms of CBCT image matching process. No clinically significant differences were observed as functions of various factors investigated in this study. Consistency in matching between RTTs and ROs in this study suggests that RTTs do not need systematic RO approval of their lung CBCT match. It should be noted that RTTs at the centers in this study receive comprehensive training in CBCT-based image matching.

PMID:33707110 | DOI:10.1016/j.jmir.2021.02.004

Eur Urol. 2021 Mar 8:S0302-2838(21)00145-7. doi: 10.1016/j.eururo.2021.02.025. Online ahead of print.

ABSTRACT

BACKGROUND: Risk stratification for localized renal cell carcinoma (RCC) relies heavily on retrospective models, limiting their generalizability to contemporary cohorts.

OBJECTIVE: To introduce a contemporary RCC prognostic model, developed using prospective, highly annotated data from a phase III adjuvant trial.

DESIGN, SETTING, AND PARTICIPANTS: The model utilizes outcome data from the ECOG-ACRIN 2805 (ASSURE) RCC trial.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary outcome for the model is disease-free survival (DFS), with overall survival (OS) and early disease progression (EDP) as secondary outcomes. Model performance was assessed using discrimination and calibration tests.

RESULTS AND LIMITATIONS: A total of 1735 patients were included in the analysis, with 887 DFS events occurring over a median follow-up of 9.6 yr. Five common tumor variables (histology, size, grade, tumor necrosis, and nodal involvement) were included in each model. Tumor histology was the single most powerful predictor for each model outcome. The C-statistics at 1 yr were 78.4% and 81.9% for DFS and OS, respectively. Degradation of the DFS, DFS validation set, and OS model’s discriminatory ability was seen over time, with a global c-index of 68.0% (95% confidence interval or CI [65.5, 70.4]), 68.6% [65.1%, 72.2%], and 69.4% (95% CI [66.9%, 71.9%], respectively. The EDP model had a c-index of 75.1% (95% CI [71.3, 79.0]).

CONCLUSIONS: We introduce a contemporary RCC recurrence model built and internally validated using prospective and highly annotated data from a clinical trial. Performance characteristics of the current model exceed available prognostic models with the added benefit of being histology inclusive and TNM agnostic.

PATIENT SUMMARY: Important decisions, including treatment protocols, clinical trial eligibility, and life planning, rest on our ability to predict cancer outcomes accurately. Here, we introduce a contemporary renal cell carcinoma prognostic model leveraging high-quality data from a clinical trial. The current model predicts three outcome measures commonly utilized in clinical practice and exceeds the predictive ability of available prognostic models.

PMID:33707112 | DOI:10.1016/j.eururo.2021.02.025

Burns. 2021 Feb 27:S0305-4179(21)00056-5. doi: 10.1016/j.burns.2021.02.020. Online ahead of print.

ABSTRACT

PURPOSE: This study examines the differences in parent-perceived and patient-reported quality of life (QoL) among young adult burn patients three years after injury and the factors affecting these differences.

METHOD: The sample comprised 35 burn patients from the Formosa Fun Coast Water Park dust explosion and their parents. The study was conducted from June 2016 to August 2018. We used self-report questionnaires to collect socio-demographic data, the adapted Chinese version of the Burn Specific Health Scale-Brief, and the Impact of Events Scale for Burn.

RESULTS: The analysis indicated that simple abilities recovered the fastest, while body image recovered the slowest. The variation trends of these factors were similar but parents’ scores were lower than patients’ scores. Parents’ post-traumatic stress disorder (PTSD) scores were higher than that of patients, but were not statistically significant. Parents’ gender and PTSD levels and patients’ burn area affected differences in parent-perceived QoL among patients. PTSD levels were significantly higher among mothers.

CONCLUSIONS: For parents, PTSD is a common response to their children experiencing burn injuries. Parents’ observations of warning signs enable early medical intervention. Establishing a family-centered care plan, providing psychological support for both parents and patients, and forming a continuous care system with efficient communication can support patients’ return to society.

PMID:33707088 | DOI:10.1016/j.burns.2021.02.020

Ultrasound Med Biol. 2021 Mar 8:S0301-5629(21)00058-2. doi: 10.1016/j.ultrasmedbio.2021.02.001. Online ahead of print.

ABSTRACT

In this study we compared three different microbubble-based approaches to the delivery of a widely used chemotherapy drug, gemcitabine: (i) co-administration of gemcitabine and microbubbles (Gem+MB); (ii) conjugates of microbubbles and gemcitabine-loaded liposomes (GemlipoMB); and (iii) microbubbles with gemcitabine directly bound to their surfaces (GembioMB). Both in vitro and in vivo investigations were carried out, respectively, in the RT112 bladder cancer cell line and in a murine orthotopic muscle-invasive bladder cancer model. The in vitro (in vivo) ultrasound exposure conditions were a 1 (1.1) MHz centre frequency, 0.07 (1.0) MPa peak negative pressure, 3000 (20,000) cycles and 100 (0.5) Hz pulse repetition frequency. Ultrasound exposure produced no significant increase in drug uptake either in vitro or in vivo compared with the drug-only control for co-administered gemcitabine and microbubbles. In vivo, GemlipoMB prolonged the plasma circulation time of gemcitabine, but only GembioMB produced a statistically significant increase in cleaved caspase 3 expression in the tumor, indicative of gemcitabine-induced apoptosis.

PMID:33707089 | DOI:10.1016/j.ultrasmedbio.2021.02.001