Categories
Nevin Manimala Statistics

Systematic review of submental artery island flap versus free flap in head and neck reconstruction

Am J Otolaryngol. 2021 Jun 18;42(6):103142. doi: 10.1016/j.amjoto.2021.103142. Online ahead of print.

ABSTRACT

PURPOSE: The aim of this systematic review is to compare the perioperative characteristics and outcomes of submental artery island flap (SAIF) to free tissue transfer (FTT) in head and neck reconstruction.

MATERIALS AND METHODS: Screening and data extraction were done with Pubmed, Embase, and Web of Science databases by two independent authors to identify randomized and observational studies that compared patient outcomes for SAIF vs. FTT for reconstruction head and neck cancer ablative surgery. Data were pooled with random-effects meta-analysis to determine pooled difference in means (DM), absolute risk differences, and 95% confidence intervals (CI). Heterogeneity was assessed with the I-squared statistic.

RESULTS: Initial query yielded 997 results, of which 7 studies met inclusion criteria. The pooled sample sizes for the SAIF and FTT cohorts were 155 and 198, respectively. SAIF reduced mean operative time by 193 min (95% CI -160 to -227), reduced hospital stay by 2.1 days (95% CI -0.9 to -3.4), and had a smaller flap area of 22.5cm2 (95% CI 6.5 to 38.4). SAIF had a 5% higher incidence of partial flap necrosis than FTT (95% CI, 1 to 10), but all other perioperative complications, including recurrence rate in malignant cases, were statistically comparable.

CONCLUSIONS: The SAIF requires less operative time, hospital stay, and has comparable perioperative outcomes to FTT, but the area of flap harvest is significantly smaller. The findings of this study add to the growing body of evidence demonstrating the safety and reliability of SAIF in head and neck reconstruction.

PMID:34174670 | DOI:10.1016/j.amjoto.2021.103142

Categories
Nevin Manimala Statistics

Using spectral indices as early warning signals of forest dieback: The case of drought-prone Pinus pinaster forests

Sci Total Environ. 2021 Jun 19;793:148578. doi: 10.1016/j.scitotenv.2021.148578. Online ahead of print.

ABSTRACT

Forest dieback processes linked to drought are expected to increase due to climate warming. Remotely sensed data offer several advantages over common field monitoring methods such as the ability to observe large areas on a systematic basis and monitoring their changes, making them increasingly used to assess changes in forest health. Here we aim to use a combined approximation of fieldwork and remote sensing to explore possible links between forest dieback and land surface phenological and trend variables derived from long Landsat time series. Forest dieback was evaluated in the field over 31 plots in a Mediterranean, xeric Pinus pinaster forest. Landsat 31-year time series of three greenness (EVI, NDVI, SAVI) and two wetness spectral indices (NMDI and TCW) were derived covering the period 1990-2020. Spectral indices from time series were decomposed into trend and seasonality using a Bayesian estimator while the relationships of the phenological and trend variables among levels of damage were assessed using linear and additive mixed models. We have not found any statistical pieces of evidence of extension or shortening patterns for the length of the phenological season over the examined 31-year period. Our results indicate that the dieback process was mainly related to the trend component of the spectral indices series whereas the phenological metrics were not related to forest dieback. We also found that plots with more dying or damaged trees displayed lower spectral indices trends after a severe drought event in the middle of the 1990s, which confirms the Landsat-derived spectral indices as indicators of early-warning signals. Drops in trends occurred earlier for wetness indices rather than for greenness indices which suggests that the former could be more appropriate for dieback detection, i.e. they could be used as early warning signals of impending loss of tree vigor.

PMID:34174606 | DOI:10.1016/j.scitotenv.2021.148578

Categories
Nevin Manimala Statistics

The effect of task rotation on activation and fatigue response of rotator cuff muscles during overhead work

Appl Ergon. 2021 Jun 23;97:103461. doi: 10.1016/j.apergo.2021.103461. Online ahead of print.

ABSTRACT

Overhead work is known as one of the ergonomic risk factors that can lead to shoulder overload and injury. Anatomical alignment of rotator cuff muscles makes them the most vulnerable to injuries during overhead work. In this study, the effect of task rotation, as one of the administrative controls to reduce the risk of injury during overhead work, on the fatigue response of rotator cuff muscles was investigated. Twelve participants performed three submaximal exertions (5, 20, and 35% of maximum voluntary contraction (MVC)) using four task rotation sequences (increasing, decreasing, upward parabolic, and downward parabolic). Median frequency of surface electromyography (EMG), shoulder strength, and ratings of perceived exertion (RPE) were used to study the fatigue response of rotator cuff muscles. Although the average normalized muscle activity was similar in all sequences, the task rotation sequence had a significant effect on the median frequency. The effect of task rotation sequence on the strength and RPE was similar to that of the median frequency but was statistically not significant. The upward parabolic task rotation sequence resulted in the lowest fatigue among all the task sequences. Performing intense exertions apart from each other, warm-up exertions, and the presence of active recovery after the intense exertions could be the factors that produced the lowest fatigue during this sequence.

PMID:34174574 | DOI:10.1016/j.apergo.2021.103461

Categories
Nevin Manimala Statistics

Regression analysis of hydro-meteorological variables for climate change prediction: A case study of Chitral Basin, Hindukush region

Sci Total Environ. 2021 Jun 21;793:148595. doi: 10.1016/j.scitotenv.2021.148595. Online ahead of print.

ABSTRACT

In the present study, hydro-meteorological variables of Chitral Basin in Hindukush region of Pakistan were studied to predict the changes in climatic components such as temperature, precipitation, humidity and river flow based on observed data from 1990 to 2019. Uncertainties in climate change projection were studied using various statistical methods, such as trend variability analysis via stationarity test and validation of regression assumptions prior to fitting of regression estimates. Also, multiple regression models were estimated for each hydro-meteorological variables for the given 30 years of observed data. Results demonstrated that temperature and, precipitation were inversely related with one another. It was observed from the regression model that temperature is decreases by 0.309 °C on the average increases in precipitation by one unit. Temperature also decreases for the increase in humidity by average 0.086 °C. Since, precipitation is negatively related with temperature, thus for increases in temperature the annual precipitation decreases by 0.278 mm annually. Humidity on the other hand, increases by 0.207% by increasing in precipitation and the temperature that causes humidity to decrease by 0.99%. Thus, it demonstrated that the flow in Chitral river increases due to precipitation by 0.306 m3/s for the change in precipitation by one unit. Findings from the present study negated the general perceptions that flow in the Chitral river has increased due to recession of glaciers with increase in the intensity of temperature.

PMID:34174604 | DOI:10.1016/j.scitotenv.2021.148595

Categories
Nevin Manimala Statistics

What is the state of the art of computer vision-assisted cytology? A Systematic Literature Review

Comput Med Imaging Graph. 2021 May 15;91:101934. doi: 10.1016/j.compmedimag.2021.101934. Online ahead of print.

ABSTRACT

Cytology is a low-cost and non-invasive diagnostic procedure employed to support the diagnosis of a broad range of pathologies. Cells are harvested from tissues by aspiration or scraping, and it is still predominantly performed manually by medical or laboratory professionals extensively trained for this purpose. It is a time-consuming and repetitive process where many diagnostic criteria are subjective and vulnerable to human interpretation. Computer Vision technologies, by automatically generating quantitative and objective descriptions of examinations’ contents, can help minimize the chances of misdiagnoses and shorten the time required for analysis. To identify the state-of-art of computer vision techniques currently applied to cytology, we conducted a Systematic Literature Review, searching for approaches for the segmentation, detection, quantification, and classification of cells and organelles using computer vision on cytology slides. We analyzed papers published in the last 4 years. The initial search was executed in September 2020 and resulted in 431 articles. After applying the inclusion/exclusion criteria, 157 papers remained, which we analyzed to build a picture of the tendencies and problems present in this research area, highlighting the computer vision methods, staining techniques, evaluation metrics, and the availability of the used datasets and computer code. As a result, we identified that the most used methods in the analyzed works are deep learning-based (70 papers), while fewer works employ classic computer vision only (101 papers). The most recurrent metric used for classification and object detection was the accuracy (33 papers and 5 papers), while for segmentation it was the Dice Similarity Coefficient (38 papers). Regarding staining techniques, Papanicolaou was the most employed one (130 papers), followed by H&E (20 papers) and Feulgen (5 papers). Twelve of the datasets used in the papers are publicly available, with the DTU/Herlev dataset being the most used one. We conclude that there still is a lack of high-quality datasets for many types of stains and most of the works are not mature enough to be applied in a daily clinical diagnostic routine. We also identified a growing tendency towards adopting deep learning-based approaches as the methods of choice.

PMID:34174544 | DOI:10.1016/j.compmedimag.2021.101934

Categories
Nevin Manimala Statistics

Development of an influenza pandemic decision support tool linking situational analytics to national response policy

Epidemics. 2021 Jun 19;36:100478. doi: 10.1016/j.epidem.2021.100478. Online ahead of print.

ABSTRACT

National influenza pandemic plans have evolved substantially over recent decades, as has the scientific research that underpins the advice contained within them. While the knowledge generated by many research activities has been directly incorporated into the current generation of pandemic plans, scientists and policymakers are yet to capitalise fully on the potential for near real-time analytics to formally contribute to epidemic decision-making. Theoretical studies demonstrate that it is now possible to make robust estimates of pandemic impact in the earliest stages of a pandemic using first few hundred household cohort (FFX) studies and algorithms designed specifically for analysing FFX data. Pandemic plans already recognise the importance of both situational awareness i.e., knowing pandemic impact and its key drivers, and the need for pandemic special studies and related analytic methods for estimating these drivers. An important next step is considering how information from these situational assessment activities can be integrated into the decision-making processes articulated in pandemic planning documents. Here we introduce a decision support tool that directly uses outputs from FFX algorithms to present recommendations on response options, including a quantification of uncertainty, to decision makers. We illustrate this approach using response information from within the Australian influenza pandemic plan.

PMID:34174521 | DOI:10.1016/j.epidem.2021.100478

Categories
Nevin Manimala Statistics

Instent restenosis and stent compression following stenting for chronic iliofemoral venous obstruction

J Vasc Surg Venous Lymphat Disord. 2021 Jun 23:S2213-333X(21)00304-8. doi: 10.1016/j.jvsv.2021.06.009. Online ahead of print.

ABSTRACT

OBJECTIVES: Instent restenosis (ISR) and stent compression (SC) are problems encountered following stenting for chronic iliofemoral venous obstruction (CIVO) that are responsible for a majority of reinterventions. However, characteristics of ISR and SC, in addition to outcomes following reintervention have not been explored in detail and represent the focus of this study.

METHODS: A retrospective analysis of contemporaneously entered EMR data on 578 limbs/patients with initial unilateral iliofemoral venous stents placed from 2014 to 2018 was performed. ISR was estimated from stent and flow channel diameters measured using duplex ultrasound (DUS). SC was estimated from rated stent diameter and actual stent diameter on DUS. Characteristics evaluated included onset of ISR/SC post stent placement and progression over time. Analysis was performed to evaluate risk factors for the development of ISR and SC. Outcomes following reintervention for ISR/SC were also appraised.

RESULTS: 578 limbs underwent stenting for stenotic lesions (NIVL/PTS). ISR was noted in 27% of limbs on post-intervention day 1. The prevalence of ISR increased to 74% by 3 months and stabilized thereafter. SC was noted in 80% of limbs on day 1 and plateaued. Of the variables evaluated as potential risk factors for ISR, IVUS determined stent inflow luminal area and shear rate were found to be significant. For SC, asymmetric stent sizing was a significant risk factor. Over a median follow up of 24 months, 95/578 (16.4%) limbs underwent reintervention for ISR, SC or a combination. The median time to reintervention was 11 months. There was no statistically significant difference in the degree of ISR/SC among patients who underwent reintervention versus those who did not [p>0.05]. However, there was a statistically significant difference in the grade of swelling (p=0.006) and VAS pain scores (p<0.0001) between those who underwent reintervention and those who did not. Primary, primary assisted and secondary patencies at 60 months, following reintervention for ISR was 70%, 98% and 84% respectively, and for SC was 70%, 99% and 84%.

CONCLUSIONS: While ISR and SC are both common following stenting for CIVO, neither are relentlessly progressive. Indication for reintervention must be a recurrence of symptoms with impairment of quality of life and not the percentage of ISR or degree of SC. Post reintervention good outcomes can be expected both in terms of clinical improvement and stent patency. Further study of the impact of shear rate on stent flow is required to help reduce the incidence of ISR.

PMID:34174500 | DOI:10.1016/j.jvsv.2021.06.009

Categories
Nevin Manimala Statistics

Nursing students’ Psychological Safety in High fidelity Simulations: Development of a new scale for psychometric evaluation

Nurse Educ Today. 2021 Jun 17;105:105017. doi: 10.1016/j.nedt.2021.105017. Online ahead of print.

ABSTRACT

BACKGROUND: In high fidelity simulation used in an educational context, measuring the psychological safety levels of students enables the understanding and analysis of the relation between the characteristics of simulation design and the factors that create a psychologically safe environment.

OBJECTIVE: To develop a new measurement of psychological safety in simulation-based learning settings using high fidelity manikins and to validate its reliability and validity.

METHODS: This is a methodological study to develop a scale of Psychological Safety in High Fidelity Simulation. A convenience sample of 242 participants recruited from four universities in Korea was analyzed. The content validity of the scale and feasibility test were conducted to assess the scale’s relevance, and comprehensiveness. An exploratory factor analysis with the principal component method and a varimax rotation, a concurrent validity analysis, and known group comparisons were conducted. Reliability was evaluated through the scale’s internal consistency.

RESULTS: Four factors were extracted, and 14 items were retained for these four factors, accounting for 72% of the total variance: (1) “Dealing with uncertainty (four items),” (2) “being exposed (four items),” (3) “being unsupported (three items),” and (4) “interpersonal risk (three items).” The Psychological Safety in High Fidelity Simulation scale score exhibited a statistically significant positive correlation with the Academic Safety Assessment tool and the Educational Satisfaction Scale in Simulation scores (p 〈001). Cronbach’s α was .91 and ranged from .75 to .88 for the sub-factors.

CONCLUSION: The Psychological Safety in High Fidelity Simulation scale is a reliable and valid tool for assessing the psychological safety of nursing students during high fidelity simulation. The scale reflects the nature of psychological safety based on the elements of simulation education and measures the degree to which specific guidance is useful for nursing educators fostering psychological safety in students.

PMID:34174511 | DOI:10.1016/j.nedt.2021.105017

Categories
Nevin Manimala Statistics

Clinical management of atypical ductal hyperplasia on vacuum-assisted biopsy of microcalcifications: External validation study of a decision tree selecting patients eligible for surveillance

Eur J Radiol. 2021 Jun 17;141:109826. doi: 10.1016/j.ejrad.2021.109826. Online ahead of print.

ABSTRACT

BACKGROUND: Atypical lesions found on percutaneous breast biopsy raise specific management issues. The aim of this study was to validate the previous performance of a decision tree defined by Forgeard et al to select a subset of patients at low-risk of surgical diagnostic upgrade that would be eligible for surveillance.

METHODS: A consecutive series of 211 patients diagnosed with ADH on vacuum-assisted biopsy (VAB) of clustered microcalcifications alone, then operated in our institution, was reviewed. Histological findings on percutaneous cores were compared with definitive diagnoses on surgical specimens. The rate of cancer underestimation on VAB was analyzed in the four arms and two management attitudes defined in the scheme, using size and quality of microcalcification removal and the number of ADH foci.

RESULTS: Ninety-eight women with ADH met the inclusion criteria. Overall, 20 cancers were diagnosed at surgery, showing a malignancy rate of 44% (17/39 patients) in the surgery group and of 5% (3/59 patients) in the surveillance group, which was not significantly different from the 2% rate in the monitored reference group (p > 0.64). The malignancy rate increased significantly with the size of clustered microcalcifications (0% when < 6mm, 17% when between 6mm and 21 mm, 48% when > 21 mm, p < 0001) and the number of ADH foci on VAB (14% when ≤ 2, 45% when > 2, p < 0.005).

CONCLUSION: Our results corroborate – within the limits of large confidence intervals – those obtained with the reference decision tree. Due to statistical uncertainty, however, they need to be prospectively validated in a broader series.

PMID:34174485 | DOI:10.1016/j.ejrad.2021.109826

Categories
Nevin Manimala Statistics

Contrast media dose adjustment to allometric parameters of body mass in multiphasic CT of the liver: A comparison of different metrics

Eur J Radiol. 2021 May 17;141:109778. doi: 10.1016/j.ejrad.2021.109778. Online ahead of print.

ABSTRACT

PURPOSE: To assess correlations of lean body weight (LBW) calculated with various formulas, total body weight (TBW), body height (BH), body mass index (BMI), body surface area (BSA) and fat-free mass (FFM) with vascular and parenchymal enhancement in multiphasic CT of the liver.

METHOD: Thirty consecutive patients underwent multiphasic CT of the liver using constant iodine dose and flow rate. Contrast enhancement of aorta, portal vein and liver was calculated by measuring mean vascular and parenchymal attenuation in pre-contrast and post-contrast phases. Correlations of TBW, BH, BMI, BSA, FFM, and LBW (calculated with formulas of Boer, Hume, James and Green&Duffull) with enhancement were tested using Spearman’s correlation coefficient. The method of Fieller et al. was used to calculate 95 % confidence intervals. A p-value ≤ 0.05 was considered statistically significant.

RESULTS: Aortal enhancement correlated strongly with TBW, BSA, LBWBoer and LBWHume and moderately with BH, BMI, FFM, LBWJames and LBWGreen&Duffull. Liver enhancement in the late arterial phase correlated moderately with TBW, FFM, LBWBoer, LBWHume and LBWGreen&Duffull and weakly with BSA. Liver enhancement in the portal venous phase correlated strongly with TBW, BSA, FFM, LBWBoer, LBWHume and LBWGreen&Duffull, whereby overlap of the 95 % CI graphs demonstrated that the differences in the correlation coefficients were not statistically significant. Liver enhancement in the delayed phase correlated moderately with BH but did not correlate significantly with any other parameter.

CONCLUSION: Regardless of the form used for calculation, LBW did not correlate statistically significantly stronger than TBW with vascular or parenchymal enhancement of the liver.

PMID:34174486 | DOI:10.1016/j.ejrad.2021.109778