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Nevin Manimala Statistics

Is Valgus Cut Angle Based on Radiographic Measurements in Total Knee Arthroplasty Really Inaccurate? A Comparison of Two- and Three-Dimensional Measurements

J Knee Surg. 2021 Apr 29. doi: 10.1055/s-0041-1728785. Online ahead of print.

ABSTRACT

Radiographs are widely used to measure distal femoral valgus cut angle (VCA) in total knee arthroplasty (TKA), but its accuracy is controversial. This study used three-dimensional (3D) reconstruction models to verify the accuracy of VCA measurements on radiographs, and explore the correlation of VCA with hip-knee-ankle (HKA) angle and lateral femoral bowing angle (FBA). A total of 444 osteoarthritis knees of 444 patients from August 2016 to June 2018 was included retrospectively. On radiographs, two-dimensional VCA (VCA-2D) was measured between the femoral mechanical axis and the distal femoral anatomical axis, and HKA was measured between the femoral mechanical axis and the tibial mechanical axis. On the coronal projection of computed tomography 3D models, the anatomical landmarks used for VCA-3D measurements were the same as those on the radiographs, FBA was measured between the proximal and distal femoral anatomical axis. The distributions of VCA-2D and VCA-3D were evaluated by means and variances. The correlation between HKA and VCA and between FBA and VCA was explored. There was a statistical difference between VCA-2D and VCA-3D (p < 0.001), but the deviation was very small (0.15 ± 0.69 degrees), 83.3% of the deviations were less than 1 degree. VCA would increase both in 2D and 3D with increasing of FBA and HKA varus. There was no statistically significant difference between VCA-2D and VCA-3D in patients with moderate varus knees (0-8 degrees of varus) and mild bowing femurs (FBA <5 degrees). Overall, the deviation caused by using radiography to measure VCA was negligible. VCA measurements using radiographs were accurate in patients with moderate varus knees and mildly bowed femurs. This study reflects level of evidence III.

PMID:33915574 | DOI:10.1055/s-0041-1728785

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Nevin Manimala Statistics

Assessment of heterogeneous treatment effect estimation accuracy via matching

Stat Med. 2021 Apr 29. doi: 10.1002/sim.9010. Online ahead of print.

ABSTRACT

We study the assessment of the accuracy of heterogeneous treatment effect (HTE) estimation, where the HTE is not directly observable so standard computation of prediction errors is not applicable. To tackle the difficulty, we propose an assessment approach by constructing pseudo-observations of the HTE based on matching. Our contributions are three-fold: first, we introduce a novel matching distance derived from proximity scores in random forests; second, we formulate the matching problem as an average minimum-cost flow problem and provide an efficient algorithm; third, we propose a match-then-split principle for the assessment with cross-validation. We demonstrate the efficacy of the assessment approach using simulations and a real dataset.

PMID:33915600 | DOI:10.1002/sim.9010

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Nevin Manimala Statistics

Evidence-Based Digital Tools for Weight Loss Maintenance: The NoHoW Project

Obes Facts. 2021 Apr 29:1-14. doi: 10.1159/000515663. Online ahead of print.

ABSTRACT

BACKGROUND: Effective interventions and commercial programmes for weight loss (WL) are widely available, but most people regain weight. Few effective WL maintenance (WLM) solutions exist. The most promising evidence-based behaviour change techniques for WLM are self-monitoring, goal setting, action planning and control, building self-efficacy, and techniques that promote autonomous motivation (e.g., provide choice). Stress management and emotion regulation techniques show potential for prevention of relapse and weight regain. Digital technologies (including networked-wireless tracking technologies, online tools and smartphone apps, multimedia resources, and internet-based support) offer attractive tools for teaching and supporting long-term behaviour change techniques. However, many digital offerings for weight management tend not to include evidence-based content and the evidence base is still limited. The Project: First, the project examined why, when, and how many European citizens make WL and WLM attempts and how successful they are. Second, the project employed the most up-to-date behavioural science research to develop a digital toolkit for WLM based on 2 key conditions, i.e., self-management (self-regulation and motivation) of behaviour and self-management of emotional responses for WLM. Then, the NoHoW trial tested the efficacy of this digital toolkit in adults who achieved clinically significant (≥5%) WL in the previous 12 months (initial BMI ≥25). The primary outcome was change in weight (kg) at 12 months from baseline. Secondary outcomes included biological, psychological, and behavioural moderators and mediators of long-term energy balance (EB) behaviours, and user experience, acceptability, and cost-effectiveness.

IMPACT: The project will directly feed results from studies on European consumer behaviour, design and evaluation of digital toolkits self-management of EB behaviours into development of new products and services for WLM and digital health. The project has developed a framework and digital architecture for interventions in the context of EB tracking and will generate results that will help inform the next generation of personalised interventions for effective self-management of weight and health.

PMID:33915534 | DOI:10.1159/000515663

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Nevin Manimala Statistics

Impact of Multiparametric Stone Measurement in Noncontrast Computer Tomography on Ureterorenoscopic Stone Removal

Urol Int. 2021 Apr 29:1-5. doi: 10.1159/000515646. Online ahead of print.

ABSTRACT

PURPOSE: Low-dose computer tomography (NCCT) is the standard imaging modality for patients with acute flank pain with a suspicion of urolithiasis. The stone size is usually measured 2D by a radiologist. We compared 3D stone measurement using different windows to the 2D measurement and evaluated the clinical impact on ureterorenoscopic stone removal (URS).

METHODS: One hundred sixty-four patients (201 stones) with a preoperative NCCT, following a URS within 4 weeks, were included in this study. Stone location, number and size of stones, operating time, and laser lithotripsy were documented. Stones were measured in 3D using bone and soft tissue window. The maximum diameter was compared to the radiological report. The U test, Kruskal-Wallis, and regression were used for statistical analyses.

RESULTS: Almost two-thirds (64.68%; 130 stones) of stone measurements in 3D with the bone window were lower than the radiologist reports in 2D. One-third (34.83%; 70 stones) of stone measurements were higher and 0.5% (1 stone) reported the same size. Using the 3D soft tissue window, 81.09% (163 stones), 17.91% (37 stones), and 1% (2 stones) of stones were measured bigger, smaller, or had the same measurement results, respectively. In the clinical setting, we could calculate a cutoff for laser lithotripsy at a maximum stone diameter of 5.70 mm (p < 0.01) with the 3D and 6.01 mm with the 2D measurements, respectively, and found a significant correlation between maximum stone diameter and operating time (p < 0.01) and number of stones and operating time (p < 0.01 with and p = 0.02 without laser).

CONCLUSION: 3D stone measurement with bone window seems to be more accurate than 2D measurement, but 2D is sufficient for planning stone treatment.

PMID:33915535 | DOI:10.1159/000515646

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Association between Frailty and 90-Day Outcomes amongst the Chinese Population: A Hospital-Based Multicentre Cohort Study

Gerontology. 2021 Apr 29:1-9. doi: 10.1159/000514948. Online ahead of print.

ABSTRACT

INTRODUCTION: Frailty has gained increasing attention as it is by far the most prevalent geriatric condition amongst older patients which heavily impacts chronic health status. However, the relationship between frailty and adverse health outcomes in China is far from clear. This study explored the relation between frailty and a panel of adverse health outcomes.

METHODS: We performed a multicentre cohort study of older inpatients at 6 large hospitals in China, with two-stage cluster sampling, from October 2018 to April 2019. Frailty was measured according to the FRAIL scale and categorized into robust, pre-frail, and frail. A multivariable logistic regression model and multilevel multivariable negative binomial regression model were used to analyse the relationship between frailty and adverse outcomes. Outcomes were length of hospitalization, as well as falls, readmission, and mortality at 30 and 90 days after enrolment. All regression models were adjusted for age, sex, BMI, surgery, and hospital ward.

RESULTS: We included 9,996 inpatients (median age 72 years and 57.8% male). The overall mortality at 30 and 90 days was 1.23 and 1.88%, respectively. At 30 days, frailty was an independent predictor of falls (odds ratio [OR] 3.19; 95% CI 1.59-6.38), readmission (OR 1.45; 95% CI 1.25-1.67), and mortality (OR 3.54; 95% confidence interval [CI] 2.10-5.96), adjusted for age, sex, BMI, surgery, and hospital ward clustering effect. At 90 days, frailty had a strong predictive effect on falls (OR 2.10; 95% CI 1.09-4.01), readmission (OR 1.38; 95% CI 1.21-1.57), and mortality (OR 6.50; 95% CI 4.00-7.97), adjusted for age, sex, BMI, surgery, and hospital ward clustering effect. There seemed to be a dose-response association between frailty categories and fall or mortality, except for readmission.

CONCLUSIONS: Frailty is closely related to falls, readmission, and mortality at 30 or 90 days. Early identification and intervention for frailty amongst older inpatients should be conducted to prevent adverse outcomes.

PMID:33915544 | DOI:10.1159/000514948

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Nevin Manimala Statistics

High expression of DLL3 is associated with a poor prognosis and immune infiltration in invasive breast cancer patients

Transl Oncol. 2021 Apr 26;14(7):101080. doi: 10.1016/j.tranon.2021.101080. Online ahead of print.

ABSTRACT

BACKGROUND: Previous studies have shown the prognostic value of delta like canonical Notch ligand 3 (DLL3) in patients with different types of tumors, but the role and predictive value of DLL3 in invasive breast cancer (IBC) have not been reported. In this study, we explored the prognostic ability and potential ways of DLL3 in IBC patients.

METHODS: We retrospectively enrolled 130 IBC patients from a single institution from 2004 to 2019 for bioinformatics and statistical analysis. The Cancer Genome Atlas breast invasive carcinoma (TCGA-BRCA) cohort was used for verification.

RESULTS: High expression of DLL3 was associated with overall survival (OS) in IBC patients (P = 0.023). Multivariate analysis further showed that DLL3 expression was an independent prognostic factor (hazard ratio [HR]: 1.08; 95% confidence interval [CI]: 1.01-1.15; P = 0.017). Time-dependent receiver operating characteristic (ROC) with the area under the curve (0.786) demonstrated that DLL3 expression can predict the survival outcome of IBC patients. Furthermore, the expression of DLL3 was related to a variety of tumor infiltrating immune cells (TIICs), particularly T cells regulatory (Tregs). Gene set enrichment analysis (GSEA) and immunohistochemistry (IHC) results indicated that DLL3 was closely related to p53 signaling pathway.

CONCLUSIONS: High expression of DLL3 was associated with poor prognosis and immune cell infiltration in IBC patients. Moreover, P53 signaling pathway may be the key pathway.

PMID:33915517 | DOI:10.1016/j.tranon.2021.101080

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Nevin Manimala Statistics

Head and neck multi-organ segmentation on dual-energy CT using dual pyramid convolutional neural networks

Phys Med Biol. 2021 Apr 29. doi: 10.1088/1361-6560/abfce2. Online ahead of print.

ABSTRACT

Organ delineation is crucial to diagnosis and therapy, while is also labor-intensive and observer-dependent. Dual energy CT (DECT) provides additional image contrast than conventional single energy CT (SECT), which may facilitate automatic organ segmentation. This work aims to develop an automatic multi-organ segmentation approach using deep learning for head-and-neck region on DECT. We proposed a Mask scoring R-CNN where comprehensive features are firstly learnt from two independent pyramid networks and are then combined via deep attention strategy to highlight the informative ones extracted from DECT. To perform multi-organ segmentation and avoid misclassification, a mask scoring subnetwork was integrated into the Mask R-CNN framework to build the correlation between the class of potential detected organ’s region-of-interest (ROI) and the shape of that organ’s segmentation within that ROI. We evaluated our model on DECT images from 127 head-and-neck cancer patients (66 training, 61 testing) with manual contours of 19 organs as ground truth. For large- and mid-sized organs such as brain and parotid, the proposed method successfully achieved average Dice similarity coefficient (DSC) larger than 0.8. For small-sized organs with very low contrast such as chiasm, cochlea, lens and optic nerves, the DSCs ranged between around 0.5 and 0.8. With the propose method, using DECT images outperforms using SECT in almost all 19 organs with statistical significance in DSC (p<0.05). Meanwhile, by using the DECT, the proposed method is also significantly superior to a recently developed FCN-based method in most of organs in terms of DSC and the 95th percentile Hausdorff distance. Quantitative results demonstrated the feasibility of the proposed method, the superiority of using DECT to SECT, and the advantage of the proposed R-CNN over FCN on the head-and-neck patient study. The proposed method has the potential to facilitate the current head-and-neck cancer radiation therapy workflow in treatment planning.

PMID:33915524 | DOI:10.1088/1361-6560/abfce2

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Nevin Manimala Statistics

In pursuit of the right tail for the COVID-19 incubation period

Public Health. 2021 Mar 26;194:149-155. doi: 10.1016/j.puhe.2021.03.011. Online ahead of print.

ABSTRACT

Definition of the incubation period for COVID-19 is critical for implementing quarantine and thus infection control. Whereas the classical definition relies on the time from exposure to time of first symptoms, a more practical working definition is the time from exposure to time of first live virus excretion. For COVID-19, average incubation period times commonly span 5-7 days which are generally longer than for most typical other respiratory viruses. There is considerable variability reported however for the late right-hand statistical distribution. A small but yet epidemiologically important subset of patients may have the late end of the incubation period extend beyond the 14 days that is frequently assumed. Conservative assumptions of the right tail end distribution favor safety, but pragmatic working modifications may be required to accommodate high rates of infection and/or healthcare worker exposures. Despite the advent of effective vaccines, further attention and study in these regards are warranted. It is predictable that vaccine application will be associated with continued confusion over protection and its longevity. Measures for the application of infectivity will continue to be extremely relevant.

PMID:33915459 | DOI:10.1016/j.puhe.2021.03.011

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Nevin Manimala Statistics

Variability in the identification of lymphovascular space invasion for early stage cervical cancer

Surg Oncol. 2021 Apr 21;38:101566. doi: 10.1016/j.suronc.2021.101566. Online ahead of print.

ABSTRACT

OBJECTIVE: To evaluate the inter- and intra-rater variability of lymphovascular space invasion (LVSI) in early stage cervical cancer.

METHODS: We identified invasive cervical cancer tissue samples from radical hysterectomies in our institutional pathology database. The cases were stained with Hematoxylin & Eosin (H&E) and immunostains (CD-31 and D2-40). They were evaluated for the presence of LVSI by 6 pathologists on 3 separate occasions: with H&E staining only, then with H&E and immunostained specimens, and finally using a shared written criterion for diagnosis of LVSI. With 80 cases, a two-sided 95% confidence interval for the Kappa of 0.7 with a precision of 0.1 on each side was estimated.

RESULTS: Stage distribution was: IA 10%, IB 85%, and IIA 5%. The majority of cases were squamous cell carcinoma (55%), followed by adenocarcinoma (39%) and adenosquamous or other histology (6%). The mean inter-rater Kappa was 0.41 (95% CI: 0.37-0.45) for H&E. Usage of immunohistochemistry made a statistically significant improvement in the mean Kappa, but it still remained low: 0.52 (p = 0.02). Adding evaluation criteria for LVSI did not significantly increase the mean Kappa: 0.49 (p = 0.16). The mean intra-rater variability of H&E staining alone compared with H&E staining plus immunostaining was 0.53 (range: 0.43-0.64). The mean Kappa comparing H&E staining and H&E staining with criteria was 0.50 (range: 0.40-0.59).

CONCLUSIONS: We noted high inter- and intra-rater variability in the diagnosis of LVSI underscoring the challenges of LVSI diagnosis. Considering the significance assigned to LVSI and its implication for treatment, comprehensive guidelines with regards to determination of LVSI status are of paramount importance.

PMID:33915484 | DOI:10.1016/j.suronc.2021.101566

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Nevin Manimala Statistics

Evaluating the association between maternal vitamin D deficiency and preeclampsia among Indian gravidas

Eur J Obstet Gynecol Reprod Biol. 2021 Apr 15;261:103-109. doi: 10.1016/j.ejogrb.2021.04.014. Online ahead of print.

ABSTRACT

OBJECTIVE: The association between vitamin D deficiency and devastating preeclampsia is still debated. In this present study, our aim is to evaluate whether a statistically significant association exists between vitamin D deficiency and preeclampsia in Indian gravidas. As to the best of our knowledge, no study of this context with such a large sample size is done in the Indian population till now.

METHOD: A case-control study was performed in the year 2015-2019 where we enrolled 1000 pregnant women with preeclampsia admitted either in labor or for induction of labor in the study group and 1000 pregnant women without preeclampsia either in labor or admitted for induction of labor at term gestation in the control group. Serum 25-hydroxyvitamin D [25 (OH)] D levels of both the groups were measured through the radioimmunoassay method and analyzed. In both the groups, samples were collected equally across all the seasons of the year to avoid confounding by seasonal variation of vitamin D. Primary outcome measures the association of vitamin D deficiency and preeclampsia. While secondary outcome measures the correlation between levels of vitamin D deficiency with the severity of preeclampsia.

RESULT: A significantly low mean vitamin D level was seen in preeclamptic women (11.0 ± 7.1 ng /ml) compared to normotensive (31.4 ± 1.7 ng/ml) with p < .001. We observed approximately 11 fold increased odds of having preeclampsia in vitamin D deficient women (OR: 11.308; 95 % CI 7.5982-14.0097). Moreover, we observed that as vitamin D level decreases, the severity of preeclampsia increases (p < .001).

CONCLUSION: Compared with normotensive women, preeclamptic women had a significantly low level of vitamin D, suggesting a significant association between vitamin D deficiency and preeclampsia.

PMID:33915489 | DOI:10.1016/j.ejogrb.2021.04.014