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Nevin Manimala Statistics

An alternative estimation of the death toll of the Covid-19 pandemic in India

PLoS One. 2022 Feb 16;17(2):e0263187. doi: 10.1371/journal.pone.0263187. eCollection 2022.

ABSTRACT

The absence of reliable registration of Covid-19 deaths in India has prevented proper assessment and monitoring of the coronavirus pandemic. In addition, India’s relatively young age structure tends to conceal the severity of Covid-19 mortality, which is concentrated in older age groups. In this paper, we present four different demographic samples of Indian populations for which we have information on both their demographic structures and death outcomes. We show that we can model the age distribution of Covid-19 mortality in India and use this modeling to estimate Covid-19 mortality in the country. Our findings point to a death toll of approximately 3.2-3.7 million persons by early November 2021. Once India’s age structure is factored in, these figures correspond to one of the most severe cases of Covid-19 mortality in the world. India has recorded after February 2021 the second outbreak of coronavirus that has affected the entire country. The accuracy of official statistics of Covid-19 mortality has been questioned, and the real number of Covid-19 deaths is thought to be several times higher than reported. In this paper, we assembled four independent population samples to model and estimate the level of Covid-19 mortality in India. We first used a population sample with the age and sex of Covid-19 victims to develop a Gompertz model of Covid-19 mortality in India. We applied and adjusted this mortality model on two other national population samples after factoring in the demographic characteristics of these samples. We finally derive from these samples the most reasonable estimate of Covid-19 mortality level in India and confirm this result using a fourth population sample. Our findings point to a death toll of about 3.2-3.7 million persons by late May 2021. This is by far the largest number of Covid-19 deaths in the world. Once standardized for age and sex structure, India’s Covid-19 mortality rate is above Brazil and the USA. Our analysis shows that existing population samples allow an alternative estimation of deaths due to Covid-19 in India. The results imply that only one out of 7-8 deaths appear to have been recorded as a Covid-19 death in India. The estimates also point to a very high Covid-19 mortality rate, which is even higher after age and sex standardization. The magnitude of the pandemic in India requires immediate attention. In the absence of effective remedies, this calls for a strong response based on a combination of non-pharmaceutical interventions and the scale-up of vaccination to make them accessible to all, with an improved surveillance system to monitor the progression of the pandemic and its spread across India’s regions and social groups.

PMID:35171925 | DOI:10.1371/journal.pone.0263187

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Nevin Manimala Statistics

Bifidobacterium lactis BL-99 modulates intestinal inflammation and functions in zebrafish models

PLoS One. 2022 Feb 16;17(2):e0262942. doi: 10.1371/journal.pone.0262942. eCollection 2022.

ABSTRACT

This study was designed to explore the therapeutics and the mechanisms of a patented and marked gastric acid and intestine juice-resistant probiotics Bifidobacterium lactis BL-99 (B. lactis BL-99) on the intestinal inflammation and functions in the zebrafish models. After feeding for 6 hours, B. lactis BL-99 was fully retained in the larval zebrafish intestinal tract and stayed for over 24 hours. B. lactis BL-99 promoted the intestinal motility and effectively alleviated aluminum sulfate-induced larval zebrafish constipation (p < 0.01). Irregular high glucose diet induced adult zebrafish intestinal functional and metabolic disorders. After fed with B. lactis BL-99, IL-1β gene expression was significantly down-regulated, and IL-10 and IL-12 gene levels were markedly up-regulated in this model (p < 0.05). The intestinal lipase activity was elevated in the adult zebrafish intestinal functional disorder model after B. lactis BL-99 treatment (p < 0.05), but tryptase content had no statistical changes (p > 0.05). B. lactis BL-99 improved the histopathology of the adult zebrafish intestinal inflammation, increased the goblet cell numbers, and up-and-down metabolites were markedly recovered after treatment of B. lactis BL-99 (p < 0.05). These results suggest that B. lactis BL-99 could relieve intestinal inflammation and promote intestinal functions, at least in part, through modulating intestinal and microbial metabolism to maintain intestinal health.

PMID:35171916 | DOI:10.1371/journal.pone.0262942

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Nevin Manimala Statistics

Prevalence of questionable research practices, research misconduct and their potential explanatory factors: A survey among academic researchers in The Netherlands

PLoS One. 2022 Feb 16;17(2):e0263023. doi: 10.1371/journal.pone.0263023. eCollection 2022.

ABSTRACT

Prevalence of research misconduct, questionable research practices (QRPs) and their associations with a range of explanatory factors has not been studied sufficiently among academic researchers. The National Survey on Research Integrity targeted all disciplinary fields and academic ranks in the Netherlands. It included questions about engagement in fabrication, falsification and 11 QRPs over the previous three years, and 12 explanatory factor scales. We ensured strict identity protection and used the randomized response method for questions on research misconduct. 6,813 respondents completed the survey. Prevalence of fabrication was 4.3% (95% CI: 2.9, 5.7) and of falsification 4.2% (95% CI: 2.8, 5.6). Prevalence of QRPs ranged from 0.6% (95% CI: 0.5, 0.9) to 17.5% (95% CI: 16.4, 18.7) with 51.3% (95% CI: 50.1, 52.5) of respondents engaging frequently in at least one QRP. Being a PhD candidate or junior researcher increased the odds of frequently engaging in at least one QRP, as did being male. Scientific norm subscription (odds ratio (OR) 0.79; 95% CI: 0.63, 1.00) and perceived likelihood of detection by reviewers (OR 0.62, 95% CI: 0.44, 0.88) were associated with engaging in less research misconduct. Publication pressure was associated with more often engaging in one or more QRPs frequently (OR 1.22, 95% CI: 1.14, 1.30). We found higher prevalence of misconduct than earlier surveys. Our results suggest that greater emphasis on scientific norm subscription, strengthening reviewers in their role as gatekeepers of research quality and curbing the “publish or perish” incentive system promotes research integrity.

PMID:35171921 | DOI:10.1371/journal.pone.0263023

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Inference is bliss: Simulation for power estimation for an observational study of a cholera outbreak intervention

PLoS Negl Trop Dis. 2022 Feb 16;16(2):e0010163. doi: 10.1371/journal.pntd.0010163. Online ahead of print.

ABSTRACT

BACKGROUND: The evaluation of ring vaccination and other outbreak-containment interventions during severe and rapidly-evolving epidemics presents a challenge for the choice of a feasible study design, and subsequently, for the estimation of statistical power. To support a future evaluation of a case-area targeted intervention against cholera, we have proposed a prospective observational study design to estimate the association between the strength of implementation of this intervention across several small outbreaks (occurring within geographically delineated clusters around primary and secondary cases named ‘rings’) and its effectiveness (defined as a reduction in cholera incidence). We describe here a strategy combining mathematical modelling and simulation to estimate power for a prospective observational study.

METHODOLOGY AND PRINCIPAL FINDINGS: The strategy combines stochastic modelling of transmission and the direct and indirect effects of the intervention in a set of rings, with a simulation of the study analysis on the model results. We found that targeting 80 to 100 rings was required to achieve power ≥80%, using a basic reproduction number of 2.0 and a dispersion coefficient of 1.0-1.5.

CONCLUSIONS: This power estimation strategy is feasible to implement for observational study designs which aim to evaluate outbreak containment for other pathogens in geographically or socially defined rings.

PMID:35171911 | DOI:10.1371/journal.pntd.0010163

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Nevin Manimala Statistics

Near-term forecasting of companion animal tick paralysis incidence: An iterative ensemble model

PLoS Comput Biol. 2022 Feb 16;18(2):e1009874. doi: 10.1371/journal.pcbi.1009874. Online ahead of print.

ABSTRACT

Tick paralysis resulting from bites from Ixodes holocyclus and I. cornuatus is one of the leading causes of emergency veterinary admissions for companion animals in Australia, often resulting in death if left untreated. Availability of timely information on periods of increased risk can help modulate behaviors that reduce exposures to ticks and improve awareness of owners for the need of lifesaving preventative ectoparasite treatment. Improved awareness of clinicians and pet owners about temporal changes in tick paralysis risk can be assisted by ecological forecasting frameworks that integrate environmental information into statistical time series models. Using an 11-year time series of tick paralysis cases from veterinary clinics in one of Australia’s hotspots for the paralysis tick Ixodes holocyclus, we asked whether an ensemble model could accurately forecast clinical caseloads over near-term horizons. We fit a series of statistical time series (ARIMA, GARCH) and generative models (Prophet, Generalised Additive Model) using environmental variables as predictors, and then combined forecasts into a weighted ensemble to minimise prediction interval error. Our results indicate that variables related to temperature anomalies, levels of vegetation moisture and the Southern Oscillation Index can be useful for predicting tick paralysis admissions. Our model forecasted tick paralysis cases with exceptional accuracy while preserving epidemiological interpretability, outperforming a field-leading benchmark Exponential Smoothing model by reducing both point and prediction interval errors. Using online particle filtering to assimilate new observations and adjust forecast distributions when new data became available, our model adapted to changing temporal conditions and provided further reduced forecast errors. We expect our model pipeline to act as a platform for developing early warning systems that can notify clinicians and pet owners about heightened risks of environmentally driven veterinary conditions.

PMID:35171905 | DOI:10.1371/journal.pcbi.1009874

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The Association of Cannabis Use Disorder and Perioperative Complications After Primary Total Knee Arthroplasty

J Am Acad Orthop Surg. 2022 Feb 15. doi: 10.5435/JAAOS-D-21-00703. Online ahead of print.

ABSTRACT

INTRODUCTION: Although studies have shown the implications of substance use on total joint arthroplasty, studies investigating the association of patients exclusively who have cannabis use disorder (CUD) after primary total knee arthroplasty (TKA) are sparse. As such, this study analyzed a private payor database to assess the relationship of CUD after primary TKA.

METHODS: Data from the Mariner data set were used to identify patients who have CUD undergoing primary TKA. Patients with CUD were ratio matched 1:5 to a comparison population by age, sex, and comorbidities, yielding 55,553 patients in the study (n = 9,260) and case-matched (n = 46,293) population. Variables compared included in-hospital length of stay, complications, and costs. A P value of less than 0.003 was considered statistically significant.

RESULTS: Patients with CUD were found to have longer in-hospital length of stay (3.61 versus 2.07 days, P < 0.0001), in addition to higher frequency and odds ratio (OR) of medical (28.08 versus 12.5; OR, 1.50, P < 0.0001) and prostheses-related complications (9.63 versus 5.16%; OR, 1.56, P < 0.0001). Patients with CUD also incurred significantly higher episode of care costs ($29,025.34 versus $24,258.17, P < 0.0001).

CONCLUSION: With the continued legalization of cannabis use across the United States, studies investigating the association of cannabis on outcomes after primary TKA are limited. The current study helps to expand the current literature on outcomes of substance abuse after total joint arthroplasty and can serve to help educate patients of potential complications after their TKA.

PMID:35171881 | DOI:10.5435/JAAOS-D-21-00703

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Nevin Manimala Statistics

Diagnostic Value of Plasmacytoid Dendritic Cells in Differentiating Pityriasis Lichenoides et Varioliformis Acuta From Lymphomatoid Papulosis

Am J Dermatopathol. 2022 Mar 1;44(3):174-178. doi: 10.1097/DAD.0000000000002063.

ABSTRACT

Pityriasis lichenoides et varioliformis acuta (PLEVA) and lymphomatoid papulosis (LyP) can often demonstrate clinical and histopathologic overlap. A recent study demonstrated significant plasmacytoid dendritic cell (pDC) recruitment in lesions of PLEVA, whereas another study reported minimal pDC recruitment in lesions of LyP. To confirm the possible diagnostic value of pDCs in differentiating PLEVA and LyP, we compared the presence and distribution of pDCs and myxovirus protein A (MxA) expression (an indirect assessment of pDC activity). In total, 19 cases of PLEVA (16 patients) and 14 cases of LyP (11 patients) were examined using immunohistochemical stains for anti-blood-derived dendritic cell antigen-2 and MxA. Individual semiquantitative scoring systems were used to assess the immunohistochemical results, and a Mann-Whitney test with a subsequent 2-tailed P test was performed for statistical analysis. No statistically significant difference in the number of pDCs in both groups was found. However, most PLEVA cases (84%) demonstrated intense and diffuse MxA expression, whereas LyP cases (71%) demonstrated weak patchy staining (P < 0.007). Our study suggests that although additional studies may be needed to determine whether pDCs are more relevant to the pathogenesis of PLEVA or LyP, pDC activity through MxA staining may play a role in differentiating PLEVA from LyP and may serve as a platform for additional studies.

PMID:35171884 | DOI:10.1097/DAD.0000000000002063

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Nevin Manimala Statistics

Evaluating diversity in neurosurgery through the use of a multidimensional statistical model: a pilot study

J Neurosurg. 2022 Jan 14:1-8. doi: 10.3171/2021.10.JNS211006. Online ahead of print.

ABSTRACT

OBJECTIVE: There is a growing body of evidence demonstrating the benefits of diversity across many domains. However, neurosurgery consistently lags most of medicine in many aspects of diversity. Any inability to make progress in this arena is likely due to the multifactorial and complex nature of the issue, which makes it difficult to meaningfully measure and track diversity within the workforce. The goal of this pilot study was to assess the utilization of a multidimensional statistical model to quantify and assess diversity within neurosurgery. The authors sought to 1) assess the diversity of neurosurgery residents using Simpson’s Diversity Index and Sullivan’s Composite Diversity Index (CDI) and 2) determine if a medical school’s intrinsic academic opportunities and resources, indicated by US News & World Report’s (USNWR’s) best research medical schools ranking, are related to the number of neurosurgery residents produced per medical school.

METHODS: A cross-sectional study of all neurosurgery residents (projected graduation years 2020-2026) and 1st-year medical students (matriculating years 2016-2019) was undertaken. Biographical diversity data (gender and matriculation data) were collected from institutional websites between December 2019 and June 2020. The CDI expresses the diversity of a given population by representing the effective proportion of categories present across all diversity attributes and was calculated for neurosurgery residents and medical students. Statistical results are reported as the median and interquartile range.

RESULTS: Neurosurgery residency program CDI (0.21, IQR 0.16-0.25) was significantly less (p < 0.001) than medical school CDI (0.42, 0.37-0.48). There was no significant difference in CDI between top-40 and non-top 40 Doximity ranked research output neurosurgery residency programs (p = 0.35) or between top-40 and non-top 40 USNWR ranked research medical schools (p = 0.11). Over a 7-year period, top-40 ranked research medical schools produced significantly more (p < 0.001) neurosurgery residents (11.9, IQR 7.1-18.9) than the non-top 40 ranked research medical schools (5.6, IQR 2.6-8.5).

CONCLUSIONS: The authors demonstrated the feasibility of using a multidimensional statistical model as a measure to understand the complex issues of diversity. Their preliminary data suggested that neurosurgery’s challenge in achieving the desired diversity relates to uneven attraction and/or recruitment across an increasingly diverse medical student body. In recent years, neurosurgery has made great progress in the arena of diversity and has shown a strong desire to do more. Utilization of these diversity measures will help the neurosurgery field to monitor progress along this valuable journey.

PMID:35171830 | DOI:10.3171/2021.10.JNS211006

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Nevin Manimala Statistics

Association between winter season and desmopressin treatment efficiency in children with monosymptomatic nocturnal enuresis: a pilot study

Int Braz J Urol. 2022 Mar-Apr;48(2):275-281. doi: 10.1590/S1677-5538.IBJU.2021.0236.

ABSTRACT

OBJECTIVES: The purpose of our study was to assess the association between the winter season and desmopressin treatment failure in South Chinese children with monosymptomatic nocturnal enuresis (MNE).

MATERIALS AND METHODS: A retrospective study was conducted to analyze the clinical data of children with monosymptomatic nocturnal enuresis who have visited our urology clinic from January to December 2019. All patients received desmopressin treatment. Final treatment outcomes were categorized as successful (complete response) or failed (absent and partial response). The relationship between winter season and treatment response to desmopressin was evaluated. Additionally, associated risk factors were investigated with both univariate and multivariate regression analysis.

RESULTS: In total, 393 patients diagnosed with MNE were included in the present study. There were no statistically significant differences in pretreatment variables at first visit between patients who visited the clinic in winter and those who did so in other seasons. However, the treatment failure rate of MNE in the winter season was higher than that of other seasons (77.50% vs. 52.74%). Multivariate logistic regression analysis demonstrated that the severity of symptoms and an initial clinic visit in the winter season were significantly related to desmopressin treatment failure in MNE patients.

CONCLUSION: Winter season and severity of symptoms are two risk factors associated with desmopressin treatment failure in MNE patients.

PMID:35170888 | DOI:10.1590/S1677-5538.IBJU.2021.0236

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Enhancement patterns of adrenal nodules on magnetic resonance imaging

Int Braz J Urol. 2022 Mar-Apr;48(2):294-302. doi: 10.1590/S1677-5538.IBJU.2021.0472.

ABSTRACT

OBJECTIVE: To compare enhancement patterns of typical adrenal adenomas, lipid-poor adenomas, and non-adenomas on magnetic resonance imaging (MRI).

MATERIALS AND METHODS: Evaluation of adrenal nodules larger than 1.0 cm, with at least 2-year follow-up, evaluated on MRI in January 2007 and December 2016. Two different protocols were included – upper abdomen MRI (delayed phase after 3 minutes) and abdomen and pelvis MRI (delayed phase after 7 minutes) – and nodules were divided in typical adenomas (characterized on out-of-phase MRI sequence), lipid-poor adenomas (based on follow-up imaging stability) and non-adenomas (based on pathological finding or follow-up imaging). T2-weighted and enhancement features were analyzed (absolute and relative washout and enhancement curve pattern), similarly to classic computed tomography equations.

RESULTS: Final cohort was composed of 123 nodules in 116 patients (mean diameter of 1.8 cm and mean follow up time of 4 years and 3 months). Of them, 98 (79%) nodules had features of typical adenomas by quantitative chemical shift imaging, and demonstrated type 3 curve pattern in 77%, mean absolute and relative washout of 29% and 16%, respectively. Size, oncologic history and T2-weighted features showed statistically significant differences among groups. Also, a threshold greater than 11.75% for absolute washout on MRI achieved sensitivity of 71.4% and specificity of 70.0%, in differentiating typical adenomas from non-adenomas.

CONCLUSION: Calculating absolute washout of adrenal nodules on MRI may help identifying proportion of non-adenomas.

PMID:35170891 | DOI:10.1590/S1677-5538.IBJU.2021.0472