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Nevin Manimala Statistics

Effects of COVID-19 on the admissions of aneurysmal subarachnoid hemorrhage: the West Greece experience

Neurol Sci. 2021 Mar 21. doi: 10.1007/s10072-021-05190-6. Online ahead of print.

ABSTRACT

BACKGROUND: Acute subarachnoid hemorrhage (SAH) due to aneurysmal rupture is a devastating vascular disease accounting for 5% of strokes. COVID-19 pandemic resulted in a decrease in elective and emergency admissions in the majority of neurosurgical centers. The main hypothesis was that fear of COVID-19 may have prevented patients with critical medical or surgical emergencies from actively presenting in emergency departments and outpatient clinics.

METHODS: We conducted a single-center, retrospective, observational study searching our institutional data regarding the incidence of spontaneous subarachnoid hemorrhage (SAH) and compare the admissions in two different periods: the pre COVID-19 with the COVID-19 period.

RESULTS: The study cohort was comprised of a total of 99 patients. The mean (SD) weekly case rate of patients with SAH was 1.1 (1.1) during the pre-COVID-19 period, compared to 1.7 (1.4) during the COVID-19 period. Analysis revealed that the volume of admitted patients with SAH was 1.5-fold higher during the COVID period compared to the pre-COVID period and this was statistically significant (ExpB = 1.5, CI 95% 1-2.3, p = 0.044). Difference in mortality did not reach any statistical significance between the two periods (p = 0.097), as well as patients’ length of stay (p = 0.193).

CONCLUSIONS: The presented data cover a more extended time period than so far published reports; it is reasonable that our recent experience may well be demonstrating a general realistic trend of overall increase in aneurysmal rupture rates during lockdown. Hospitalization of patients with SAH cannot afford any reductions in facilities, equipment, or personnel if optimum outcomes are desirable.

PMID:33745041 | DOI:10.1007/s10072-021-05190-6

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Threshold effects of capital investments on carbon emissions in G20 economies

Environ Sci Pollut Res Int. 2021 Mar 21. doi: 10.1007/s11356-021-13046-x. Online ahead of print.

ABSTRACT

Investment in capitals is sacrosanct to launch a country to a greater path of sustainable development. Notwithstanding, its deleterious impacts on environment are equally incontestable. In light of this stark reality, this paper examines the threshold effects of capital investments on carbon emissions in G20 economies over the period, 1992-2014, for which data are available. The study uses both exogenously determined and endogenously determined thresholds to uncover the relationship. While the former relies on median approach to determining the threshold on the one hand, the latter uses both the fixed effects panel threshold model proposed by (Hansen J Econ 93:345-368, 1999) and the bootstrap method by (Hansen Econometrica 68:575-603, 2000) to assess the statistical relevance of the threshold effects on the other hand. The results of the exogenously determined thresholds show higher statistical significant environmental impacts of capital investments at a median threshold of above 3.068 than when it is lesser. The findings of the latter approach indicate the relationship between capital investments and carbon emissions to be non-linear for the G20 countries. More specifically, this study establishes a single-threshold level of capital investment on carbon emissions for the group of countries. The threshold estimator of 3.434 is established at the 95% confidence interval. Beyond this point, the environmental impacts of capital investments are imaginable. On the policy front, keeping to the limit set by threshold effects would go a long way to stemming environmental pollution and mitigating climatic change impacts.

PMID:33745025 | DOI:10.1007/s11356-021-13046-x

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Nevin Manimala Statistics

No decrease in incidence of arthroscopic meniscectomy in a Canadian province

Knee Surg Sports Traumatol Arthrosc. 2021 Mar 21. doi: 10.1007/s00167-021-06534-7. Online ahead of print.

ABSTRACT

PURPOSE: Arthroscopic meniscectomy (APM) is the most common procedure in orthopedic surgery, despite increasing evidence questioning its benefit over conservative management for treatment of degenerative meniscal tears. The purpose of this study is to determine the epidemiology and trends of APM in Saskatchewan, a Canadian province, over a 20 year period.

METHODS: Physician billing codes were used to identify patients who underwent APM in Saskatchewan between January 1, 1998 and December 31, 2017. Records were obtained from eHealth Saskatchewan, a provincial health database. Data was analyzed for overall incidence and age-specific trends of APM.

RESULTS: A total of 35,099 APMs were performed during the study period. The population of Saskatchewan ranged from 992,314 to 1,150,782 (median 1,017,368) during this time interval, with 81 orthopedic surgeons performing APM. Overall incidence rate of APM did not change significantly over time. No decrease was observed in patients presumed to have degenerative tears (≥ 50 years). The number of meniscectomies in patients ≥ 50 years was significantly greater during the second decade of study compared to the first (OR 1.48, p < 0.01). Conversely, the increase in incidence rate among older patients was not statistically significant (R2 = 0.125, n.s.).

CONCLUSION: Overall incidence rate of APM in Saskatchewan has not decreased during the last 20 years. Furthermore, APM frequency increased over time for individuals ≥ 50 years. Several regional factors may have contributed to these findings, including the large proportion of Saskatchewan residents engaged in physically demanding work and barriers to accessing physiotherapy services. Given recent evidence disputing the benefit of APM over conservative measures, this study highlights the need for improved dissemination of evidence, as well as the importance of an individualized treatment plan to address patient-specific factors.

LEVEL OF EVIDENCE: Level IV.

PMID:33745007 | DOI:10.1007/s00167-021-06534-7

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Revisiting Co-Trimoxazole Prophylaxis for African Adults in The Era of Antiretroviral Therapy: A Randomized Controlled Clinical Trial

Clin Infect Dis. 2021 Mar 21:ciab252. doi: 10.1093/cid/ciab252. Online ahead of print.

ABSTRACT

BACKGROUND: Daily co-trimoxazole is recommended for African adults living with HIV irrespective of antiretroviral treatment, immune status, or disease stage. Benefits of continued prophylaxis and whether co-trimoxazole can be stopped following immune reconstitution are unknown.

METHODS: We conducted a randomized, controlled trial at two sites in Malawi that enrolled HIV-infected adults with undetectable viral load and CD4 count of >250/mm 3 and randomized them to continue daily co-trimoxazole, discontinue daily co-trimoxazole and begin weekly chloroquine, or discontinue daily co-trimoxazole. The primary endpoint was the preventive effect of co-trimoxazole prophylaxis against death or World Health Organization (WHO) HIV/AIDS Stage 3-4 events, using Cox proportional hazards modelling, intention to treat population.

RESULTS: 1499 adults were enrolled. The preventive effect of co-trimoxazole on the primary endpoint was 22% (95%CI -14-47%, p=0.20) versus no prophylaxis and 25% (95%CI -10-48%, p=0.14) versus chloroquine. When WHO HIV/AIDS Stage 2 events were added to the primary endpoint, preventive effect increased to 31% (95%CI 3-51%, p=0.032) and 32% (95%CI 4-51%, p=0.026), respectively. Co-trimoxazole and chloroquine prophylaxis effectively prevented clinical malaria episodes (3.8 and 3.0, respectively, versus 28/100 person-years, p<0.001).

CONCLUSIONS: Malawian adults living with HIV who immune reconstituted on ART and continued co-trimoxazole prophylaxis experienced fewer deaths and WHO HIV/AIDS Stage 3-4 events compared to prophylaxis discontinuation, though statistical significance was not achieved. Cotrimoxazole prevented a composite of death plus WHO HIV/AIDS Stage 2-4 events. Given poor healthcare access and lack of routine viral load monitoring, co-trimoxazole prophylaxis should continue in adults on ART after immune reconstitution in sub-Saharan Africa.

PMID:33744963 | DOI:10.1093/cid/ciab252

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Genetic-fuzzy logic model for a non-invasive measurement of a stroke volume

Comput Methods Programs Biomed. 2021 Mar 12;203:106046. doi: 10.1016/j.cmpb.2021.106046. Online ahead of print.

ABSTRACT

BACKGROUND: Despite the importance of stroke volume readings in understanding the work of the cardiovascular system in patients, its routine daily measurement outside of a hospital in the absence of special equipment presents a problem for a comprehensive assessment of the heart performance.

OBJECTIVE: The purpose of this study was to develop a new non-invasive technique for measuring a stroke volume based on the relationship between time skin warming and a blood flow.

METHODS: . Ninety two randomly selected volunteers (54 males, aged 30.1 ± 11.9 years old, and 38 females, aged 35.8 ± 12.4 years old) were recruited for this study. The time skin warming was determined by applying on the wrist above the arterial pulsation a thermoelectric cooler using the Peltier effect. During recording the participants were in the supine position. Blood pressure was measured by sphygmomanometer. Heart performance was assessed by Murata ballistocardiographic sensor, detecting displacement of the whole body during each cardiac ejection of blood. The data provided by this sensor included heart rate, respiratory rate, heart rate variability and a stroke volume. Linear, non-linear statistical regression models and fuzzy logic were used to analyse the degree of interrelation between BCG-measured stroke volume and the time skin warming.

RESULTS: Comparative analysis of results indicated that the generic-fuzzy logic model demonstrated a high level of dependency (R = 0.803) between input (participants’ time skin warming, pulse pressure and age) and output (ballistocardiographic stroke volume) parameters.

CONCLUSIONS: The method described in the paper offers a simple, portable, and low-cost solution that can even be used in a home setting to measure the stroke volume. The principle of the proposed method is based on the interrelation between time skin warming and blood flow. The latter, corrected by corresponding age and pulse pressure, expresses the participant’s stroke volume. Adopting the genetic-fuzzy model significantly improved the accuracy of stroke volume’s measurement and made the proposed method reliable for assessing of the cardiovascular system. This daily practice technique would help healthcare provider get an early diagnosis of cardiac dysfunctions and track heart changes during stress, e.g., in sport.

PMID:33743490 | DOI:10.1016/j.cmpb.2021.106046

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Nevin Manimala Statistics

Uptake of hysterectomy and bilateral salpingo-oophorectomy in carriers of pathogenic mismatch repair variants: a Prospective Lynch Syndrome Database report

Eur J Cancer. 2021 Mar 17;148:124-133. doi: 10.1016/j.ejca.2021.02.022. Online ahead of print.

ABSTRACT

PURPOSE: This study aimed to report the uptake of hysterectomy and/or bilateral salpingo-oophorectomy (BSO) to prevent gynaecological cancers (risk-reducing surgery [RRS]) in carriers of pathogenic MMR (path_MMR) variants.

METHODS: The Prospective Lynch Syndrome Database (PLSD) was used to investigate RRS by a cross-sectional study in 2292 female path_MMR carriers aged 30-69 years.

RESULTS: Overall, 144, 79, and 517 carriers underwent risk-reducing hysterectomy, BSO, or both combined, respectively. Two-thirds of procedures before 50 years of age were combined hysterectomy and BSO, and 81% of all procedures included BSO. Risk-reducing hysterectomy was performed before age 50 years in 28%, 25%, 15%, and 9%, and BSO in 26%, 25%, 14% and 13% of path_MLH1, path_MSH2, path_MSH6, and path_PMS2 carriers, respectively. Before 50 years of age, 107 of 188 (57%) BSO and 126 of 204 (62%) hysterectomies were performed in women without any prior cancer, and only 5% (20/392) were performed simultaneously with colorectal cancer (CRC) surgery.

CONCLUSION: Uptake of RRS before 50 years of age was low, and RRS was rarely undertaken in association with surgical treatment of CRC. Uptake of RRS aligned poorly with gene- and age-associated risk estimates for endometrial or ovarian cancer that were published recently from PLSD and did not correspond well with current clinical guidelines. The reasons should be clarified. Decision-making on opting for or against RRS and its timing should be better aligned with predicted risk and mortality for endometrial and ovarian cancer in Lynch syndrome to improve outcomes.

PMID:33743481 | DOI:10.1016/j.ejca.2021.02.022

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Nevin Manimala Statistics

Understanding stream bank erosion and deposition in Iowa, USA: A seven year study along streams in different regions with different riparian land-uses

J Environ Manage. 2021 Mar 17;287:112352. doi: 10.1016/j.jenvman.2021.112352. Online ahead of print.

ABSTRACT

Agricultural activities such as row-cropping and grazing, have accelerated stream bank erosion. Accelerated stream bank erosion increases nonpoint source pollutants in aquatic ecosystems, significantly degrading them. Mitigating stream bank erosion is a priority worldwide, especially in agricultural watersheds. The objective of this study was to analyze the impacts of riparian land-use management on stream bank erosion and deposition, along with analyzing its temporal and spatial patterns. The study was conducted in three regions of Iowa (central, northeast and southeast) along 30 stream reaches adjacent to seven different riparian land-uses. The riparian land-uses were riparian forest buffers, grass filters, pastures with the cattle excluded from the stream, intensive rotational grazing, rotational grazing, continuous grazing and row crop fields. Seasonal erosion and deposition data (Spring, Summer and Autumn) were collected along these reaches for 5 years and yearly for the following two years. To analyze the data, conventional statistical methods (ANOVA and Tukey’s test) along with innovative techniques (percentile plots, cumulative erosion curves and bubble charts) were utilized. Based on the analysis, of this extensive in time (seven years) and large in size (1500 pins measured 17 times in three regions) field dataset, major results were obtained in regard to stream bank erosion in Iowa, USA. Stream banks exhibited high year-to-year variation in erosion and deposition showcasing the need for long-term datasets to better understand stream bank erosion and deposition. Seasonal erosion, also had high variability with Spring recording the most erosion followed by Summer and Autumn. Certain seasons exhibited high stream bank erosion indicating that managers need to focus on these seasons, to reduce erosion effectively. In addition, seasonal measurements can highlight depositional events that might be masked with annual measurements. Riparian land-uses significantly impacted stream bank erosion. Riparian forest buffers and grass filters significantly mitigated stream bank erosion while traditional agricultural practices like continuous grazing and row-crop agriculture had accelerated stream bank erosion. Finally, the percentile plots, cumulative erosion curves and bubble charts captured some stream bank responses that would have been unnoticed using conventional statistical methods, allowing decision makers, stakeholders and the general public, to support and approve measures to mitigate this environmental problem. Nature-based solutions utilizing riparian perennial vegetation can sustainably mitigate stream bank erosion.

PMID:33743416 | DOI:10.1016/j.jenvman.2021.112352

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Cobalt exposure increases the risk of fibrosis of people living near E‑waste recycling area

Ecotoxicol Environ Saf. 2021 Mar 17;215:112145. doi: 10.1016/j.ecoenv.2021.112145. Online ahead of print.

ABSTRACT

The toxicity of heavy metals is one of the major public health issues leading to hazardous effects on humans. Many studies focus on the adverse effects on people who were working in or living near E-waste recycling. However, little is known to the sustaining effects of E-waste exposure on human health after the recycling factories were shut down. In the present study, we collected the blood of people living near E‑waste recycling facilities after the recycling factories were closed for 2 years. Eight heavy metals were examined in all blood samples. The results revealed that the blood levels of lead (Pb), nickel (Ni), cobalt (Co), mercury (Hg) were significantly higher in the exposed group than in the reference group, and no difference was observed for copper (Cu), zinc (Zn), stannum (Sn), cadmium (Cd). Transforming growth factor-β (TGF-β) and alpha-smooth muscle actin (α-SMA) were analyzed as the important indicators of fibrosis, which were statistically significantly higher in the exposed group than in the reference group. 8-isoprostane (8-I) and malondialdehyde (MDA) as the biomarkers of oxidative stress (OS) were elevated in the exposed group. Furthermore, both Spearman correlation and multiple linear regression showed that Co was positively correlated with TGF-β, α-SMA and 8-I in the exposed group. Accordingly, we speculate that high concentrations of Co dissolved in the blood may increase the risk of tissue fibrosis through stimulating myofibroblast activation and OS involve in the process, which may provide some potential new hints for the intervention for tissue fibrosis in the future.

PMID:33743401 | DOI:10.1016/j.ecoenv.2021.112145

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Progression from Pneumonia to ARDS as a Predictor for Fatal COVID-19

J Infect Public Health. 2020 Dec 30;14(4):504-507. doi: 10.1016/j.jiph.2020.12.026. Online ahead of print.

ABSTRACT

There is a serious concern over the variation of case fatality of COVID-19 patients that reflects the preparedness of the medical care system in response to the surge of pneumonia patients. We aimed to quantify the disease spectrum of COVID-19 on which we are based to develop a key indicator on the probability of progression from pneumonia to acute respiratory disease syndrome (ARDS) for fatal COVID-19. The retrospective cohort on 12 countries that have already experienced the epidemic of COVID-19 with available open data on the conformed cases with detailed information on mild respiratory disease (MRD), pneumonia, ARDS, and deaths were used. The pooled estimates from three countries with detailed information were 73% from MRD to pneumonia and 27% from MRD to recovery and the case-fatality rate of ARDS was 43%. The progression from pneumonia to ARDS varied from 3% to 63%. These key estimates were highly associated with the case fatality rates reported for each country with a statistically significant positive relationship (adjusted R2 = 95%). Such a quantitative model provides key messages for the optimal medical resources allocation to a spectrum of patients requiring quarantine and isolation at home, isolation wards, and intensive care unit in order to reduce deaths from COVID-19.

PMID:33743372 | DOI:10.1016/j.jiph.2020.12.026

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Fitting unbranching skeletal structures to objects

Med Image Anal. 2021 Mar 4;70:102020. doi: 10.1016/j.media.2021.102020. Online ahead of print.

ABSTRACT

Representing an object by a skeletal structure can be powerful for statistical shape analysis if there is good correspondence of the representations within a population. Many anatomic objects have a genus-zero boundary and can be represented by a smooth unbranching skeletal structure that can be discretely approximated. We describe how to compute such a discrete skeletal structure (“d-s-rep”) for an individual 3D shape with the desired correspondence across cases. The method involves fitting a d-s-rep to an input representation of an object’s boundary. A good fit is taken to be one whose skeletally implied boundary well approximates the target surface in terms of low order geometric boundary properties: (1) positions, (2) tangent fields, (3) various curvatures. Our method involves a two-stage framework that first, roughly yet consistently fits a skeletal structure to each object and second, refines the skeletal structure such that the shape of the implied boundary well approximates that of the object. The first stage uses a stratified diffeomorphism to produce topologically non-self-overlapping, smooth and unbranching skeletal structures for each object of a population. The second stage uses loss terms that measure geometric disagreement between the skeletally implied boundary and the target boundary and avoid self-overlaps in the boundary. By minimizing the total loss, we end up with a good d-s-rep for each individual shape. We demonstrate such d-s-reps for various human brain structures. The framework is accessible and extensible by clinical users, researchers and developers as an extension of SlicerSALT, which is based on 3D Slicer.

PMID:33743355 | DOI:10.1016/j.media.2021.102020