Count Response Research Articles

Analysis of the Railway Accident-Related Damages in South Korea

Railway accidents are critical issues characterized by a large number of injuries and fatalities per accident due to massive public transport systems. This study proposes a new approach for evaluating the damages resulting from railway accidents using the two-part models (TPMs) such as the zero-inflated Poisson regression model (ZIP model) and the zero-inflated negative-binomial regression model (ZINB model) for the non-negative count measurements and the zero-inflated gamma regression model (ZIG model) and the zero-inflated log-normal regression model (ZILN model) for the semi-continuous measurements. The models are employed for the evaluation of the railway accidents on Korea Railroad, considering the accident damages, such as the train delay time, the number of trains delayed and the cost of considering the accident count responses, for the period 2008 to 2016. From the results obtained, we found that the human-related factors, the high-speed railway system or the Korea Train Express (KTX) and the number of casualties, are the main cost-escalating factors. The number of trains delayed and the amount of delay time tend to increase both the probability of incurring costs and the amount of cost. For better evaluation, the railway accident data should contain accurate information with less recurrence of zeros.

Partitioning variation in multilevel models for count data.

A first step when fitting multilevel models to continuous responses is to explore the degree of clustering in the data. Researchers fit variance-component models and then report the proportion of variation in the response that is due to systematic differences between clusters. Equally they report the response correlation between units within a cluster. These statistics are popularly referred to as variance partition coefficients (VPCs) and intraclass correlation coefficients (ICCs). When fitting multilevel models to categorical (binary, ordinal, or nominal) and count responses, these statistics prove more challenging to calculate. For categorical response models, researchers appeal to their latent response formulations and report VPCs/ICCs in terms of latent continuous responses envisaged to underly the observed categorical responses. For standard count response models, however, there are no corresponding latent response formulations. More generally, there is a paucity of guidance on how to partition the variation. As a result, applied researchers are likely to avoid or inadequately report and discuss the substantive importance of clustering and cluster effects in their studies. A recent article drew attention to a little-known exact algebraic expression for the VPC/ICC for the special case of the two-level random-intercept Poisson model. In this article, we make a substantial new contribution. First, we derive exact VPC/ICC expressions for more flexible negative binomial models that allows for overdispersion, a phenomenon which often occurs in practice. Then we derive exact VPC/ICC expressions for three-level and random-coefficient extensions to these models. We illustrate our work with an application to student absenteeism. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Robust inference in the joint modeling of multilevel zero‐inflated Poisson and Cox models

A popular method for simultaneously modeling of correlated count response with excess zeros and time to event is by means of the joint models. In these models, the likelihood-based methods (such as expectation-maximization algorithm and Newton-Raphson) are used for estimating the parameters, but in the presence of contaminations, these methods are unstable. To overcome this challenge, we extend the M-estimator methods and propose a robust estimator approach to obtain a robust estimation of the regression parameters in the joint model. Our proposed algorithm has two steps (Expectation and Solution). In the expectation step, the likelihood function is expected by conditioning on the observed data and in the solution step, the parameters are computed, with solving robust estimating equations. Therefore, this algorithm achieves robustness by applying robust estimating equations and weighted likelihood in the S-step. Simulation studies under various situations of contaminations show that the robust algorithm gives us consistent estimates with a smaller bias than likelihood-based methods. The application section uses data on factors affecting fertility and birth spacing.

Locally efficient semiparametric estimator for zero-inflated Poisson model with error-prone covariates

Overdispersion is a common phenomenon in count or frequency responses in Poisson models. For example, number of car accidents on a highway during a year period. A similar phenomenon is observed in electric power systems, where cascading failures often follows some distribution with inflated zero. When the response contains an excess amount of zeros, zero-inflated Poisson (ZIP) is the most favourable model. However, during the data collection process, some of the covariates cannot be accessed directly or are measured with error among numerous disciplines. To the best of our knowledge, little existing work is available in the literature that tackles the population heterogeneity in the count response while some of the covariates are measured with error. With the increasing popularity of such outcomes in modern studies, it is interesting and timely to study zero-inflated Poisson models in which some of the covariates are subject to measurement error while some are not. We propose a flexible partial linear single index model for the log Poisson mean to correct bias potentially due to the error in covariates or the population heterogeneity. We derive consistent and locally efficient semiparametric estimators and study the large sample properties. We further assess the finite sample performance through simulation studies. Finally, we apply the proposed method to a real data application and compare with existing methods that handle measurement error in covariates.

Evaluation of the Relationship Between Initial Lymphocyte Count and Molecular Response to Imatinib Therapy in Chronic Myeloid Leukaemia Patients

Evaluation of the Relationship Between Initial Lymphocyte Count and Molecular Response to Imatinib Therapy in Chronic Myeloid Leukaemia Patients

Secondary School Administrators' Knowledge and Perceptions of the Athletic Training Profession, Part I: Specific Considerations for Athletic Directors.

Athletic directors are charged with making impactful decisions for secondary school athletic programs that mitigate risks for stakeholders. This includes decision making regarding the provision of medical care for student-athletes. To date, few researchers have explored athletic directors' perceptions of the athletic training profession. To evaluate public school athletic directors' knowledge and perceptions of the athletic trainer (AT) role. Concurrent mixed-methods study. Cross-sectional online questionnaire. Athletic directors representing all 50 states and the District of Columbia (N = 954; 818 men, 133 women, 3 preferred not to answer; age = 47.8 ± 9.1 years; time in current role = 9.8 ± 8.3 years). The questionnaire was composed of demographics, quantitative measures that assessed athletic directors' knowledge and perceived value of ATs, and open-ended questions allowing for expansion on their perspectives. Descriptive statistics were reported, with key quantitative findings presented as count responses and overall percentages. Qualitative data were analyzed using the general inductive approach. A majority of respondents recognized ATs' role in injury prevention (99.8%), first aid and wound care (98.8%), therapeutic interventions (93.8%), and emergency care (91.6%). Approximately 61% (n = 582) identified AT employment as a top sport safety measure, and 77% (n = 736) considered an AT to be extremely valuable to student-athlete health and safety. Athletic directors appeared to recognize the value of ATs as they provided "peace of mind" and relieved coaches and administration of the responsibility for making medical decisions. Athletic directors seemed to recognize the value ATs brought to the secondary school setting and demonstrated adequate knowledge regarding ATs' roles and responsibilities. Educational efforts for this population should focus on ATs' tasks that add to their perceived value but are not frequently in the public eye, which may influence hiring decisions.

Secondary School Administrators' Knowledge and Perceptions of the Athletic Training Profession, Part II: Specific Considerations for Principals.

Secondary school administrators fulfill many leadership roles, including creating and implementing policies to help ensure the safety of athletic programs. However, few researchers have examined principals' awareness and perceptions of the athletic trainer's (AT's) role. To explore secondary school principals' knowledge of the roles and responsibilities of ATs and perceptions of athletic training. Concurrent mixed-methods study. Cross-sectional online questionnaire. Principals (n = 686; age = 48.1 ± 7.8 years, time in position = 7.1 ± 5.8 years) represented public secondary schools across the United States. The web-based questionnaire was composed of demographics, various quantitative items assessing knowledge and perceived value of ATs, and open-ended questions. Descriptive statistics summarized demographic data. Select quantitative measures are reported as count responses and overall percentages. Responses to open-ended questions were analyzed inductively. We obtained a 5% response rate (686 of 13 517). Approximately 93% (n = 637) of responding principals considered an AT to be a trusted source of medical information. The most frequently selected skills they believed ATs were qualified to perform were injury prevention (99.1%), first aid/wound care (96.5%), and therapeutic intervention (91.4%). Sixty-three percent (n = 430) of participants considered an AT to be extremely valuable to student-athlete health and safety. Our results indicated that secondary school principals had a vague understanding of AT "training" and appreciated the immediacy of care ATs could provide. They also appeared to use decentralized hiring practices. Secondary school principals identified ATs as a trusted source of medical information and recognized the role ATs played in the immediate care of athletic-related injuries. However, principals had a limited understanding of the qualifications and educational requirements of ATs. Future professional advocacy efforts targeting this stakeholder group should highlight all medical services an AT provides and emphasize the AT's value in schools that sponsor athletics programs.

Consistent Efficacy Demonstrated By Avatrombopag in Immune Thrombocytopenia (ITP) Regardless of the Number of Lines of Prior ITP Treatment

Background: Clinical management of ITP depends on both disease severity and risk of bleeding. Treatment typically is considered when platelet counts (PC) fall below 30,000/µL, with a target PC of ≥50,000/µL to mitigate the risk of bleeding. The standard-of-care after failure of 1st line therapy (corticosteroids or intravenous immunoglobulin) has been shifting from splenectomy and rituximab, toward an increased use of thrombopoietin receptor agonists (TPO-RAs), as supported by the recent American Society of Hematology guidelines (Neunert 2019). The TPO-RAs eltrombopag (ELT) and romiplostim (ROMI) have well understood efficacy profiles, but ELT has an FDA boxed safety warning for hepatotoxicity, necessitating hepatic function monitoring. Additionally, ELT is an orally administered chelating agent that requires dosing two hours prior to, or four hours after, meals containing polyvalent cations such as calcium or magnesium to mitigate clinically relevant effects on the pharmacokinetic profile (ELT prescribing information). In addition, ROMI, an injection, is typically is administered by a health care practitioner. Avatrombopag (AVA) is an oral TPO-RA for patients with ITP. In clinical trials, AVA rapidly increased platelet counts as early as day 5 and maintained the median PC in the target range (50 to 150×109/L) with chronic dosing. Further, it has an exposure-adjusted safety profile generally comparable to placebo and no boxed safety warning for hepatotoxicity. AVA does not chelate polyvalent cations; therefore it is administered with food, and there are no restrictions regarding meal composition. Aims: To understand how the number of prior ITP treatments impacted the efficacy of avatrombopag in a Phase 3 study. Methods: A 6-month, multicenter, randomized, double-blind, Phase 3 study enrolled 32 AVA and 17 placebo-treated (PBO) patients with ITP. The primary endpoint was the median number of cumulative weeks of platelet count (PC) response (achieving a PC ≥50,000/µL) over the course of the study without rescue medication. Patients receiving any rescue medication during the study were deemed to be non-responders for the remainder of the study. Due to the limited number of study participants, for the post-hoc analyses reported here, the study population was segmented by whether a patient had received <3 or ≥3 prior ITP treatments upon entering the Phase 3 clinical trial. Analyses of efficacy measures were performed in these two sub-populations and are presented for hypothesis generation. Results: Table 1 shows key differences in baseline characteristics between each group, suggesting that those receiving ≥3 prior ITP medications may have had more refractory disease. The median cumulative number of weeks of PC response for the entire population during the study was 12.4 vs. 0.0 for AVA and PBO respectively (p<0.0001), and the mean was 12.0 vs 0.1. For patients receiving <3 prior ITP treatments (n=13), the median and mean cumulative number of weeks of PC response were 13.7 and 12.2 for AVA and 0.0 and 0.0 for PBO; for patients receiving ≥3 prior ITP treatments (n=19), the median and mean were 11.0 and 11.8 weeks respectively for AVA and 0.0 and 0.2 for PBO. The proportion of AVA patients achieving a PC response at least once during the study was 87.5% for the entire population, 84.6% for those receiving <3 and 89.5% for those with ≥3 prior ITP treatments. Only 1 placebo patient ever achieved a response level PC, and that patient had received ≥3 prior ITP treatments. Similar results were noted for achieving a PC response twice or more during the study. A PC response at Day 8 was noted in 65.6% of the AVA patients and 0.0% in PBO (p<0.0001) overall, with 76.9% and 57.9% of AVA patients receiving <3 and ≥3 prior ITP treatments responding at Day 8 respectively. Finally, a durable PC response (achieving a PC ≥50,000/µL for 6 of the final 8 weeks of the study, calculated in an intent-to-treat fashion) was noted in 34.4% of AVA patients and 0.0% for PBO overall (p=0.009), while 38.5% and 31.6% of AVA patients having received <3 or ≥3 prior ITP treatments respectively. Conclusions: In this Phase 3 study, the number of prior ITP treatments a patient had received did not seem to definitively predict PC response to AVA, though on some measures the group receiving <3 fared slightly better. These data suggest that AVA efficacy is relatively consistent, even if a patient has received multiple prior ITP therapies before AVA initiation. Disclosures Vredenburg: Dova Pharmaceuticals: Current Employment. Tian:Dova Pharmaceuticals: Current Employment. Jamieson:Dova Pharmaceuticals: Current Employment. McCrae:Rigel: Consultancy; Dova: Consultancy; Momenta Pharmaceuticals: Consultancy; Novartis: Honoraria.

Extensive Variability in Platelet Count, Bleeding, and Quality of Life Outcome Measures in Adult and Pediatric Immune Thrombocytopenia: An Appraisal from a Critical Review of the Literature

Introduction: Despite publication of standardized platelet count response definitions by the immune thrombocytopenia (ITP) International Working Group (IWG) in 2009, there remains considerable variability in the definition of platelet count outcomes across ITP studies. Moreover, there is no widely-accepted bleeding scale, health-related quality of life (HRQoL) inventories, or definition of remission for use in ITP patients, all critical outcome measures not addressed in the IWG Report. This heterogeneity makes comparison of response rates and outcomes between studies challenging. Therefore, to better understand current practices and inform future standardization efforts, we performed a systematic review of ITP studies to characterize how these outcomes have been measured in the decade following publication of the IWG Report. Methods: We performed a systematic review of PubMed/MEDLINE-indexed manuscripts published from January 1, 2010 through December 31, 2019 that described a platelet count, bleeding, and/or HRQoL measure in reflection of treatment response in adult and pediatric ITP. Following initial search, two authors (H.A. and R.G.) screened each abstract for inclusion, then read each included full text manuscript to collect outcome measures. Interventional studies with ≥10 patients and observational studies with ≥50 patients were included; manuscripts without abstracts and non-English language manuscripts were excluded. Results: Studies. The PubMed/MEDLINE search revealed 1562 manuscripts; following abstract screening and manuscript review, 168 manuscripts met inclusion criteria for the study. Of the 168 studies, 110 studies evaluated adults, 41 evaluated children, and 17 evaluated both adults and children; 99 were prospective (including 32 randomized trials) and 69 were retrospective observational studies. Platelet Outcomes. 141 studies (including 28 randomized trials, 53 non-randomized prospective studies and 60 retrospective observational studies) reported platelet response outcomes and 11 reported platelet count remission definitions. Of the 141 reporting response outcomes, 61 (43%) used IWG definitions and 80 (57%) did not. Of these 80 studies, there were a total of 21 distinct platelet count outcome definition schemes (Figure 1). The majority of randomized trials (22/28, 79%) and other prospective studies (37/53, 70%) did not use IWG definitions; instead, a plurality of these studies used a Plt ≥50 × 109/L to define a treatment response, without definitions for complete, partial, or minor response. Most retrospective observational studies (39/60, 65%), however, used IWG definitions. Of the 11 studies reporting remission definitions, a platelet count of ≥100 × 109/L with or without treatment over a time period of ≥6 months was the most commonly used definition of remission, although a minority of studies used thresholds of ≥50 × 109/L or ≥150 × 109/L. Bleeding Outcomes. Bleeding outcomes were reported in a systematic fashion in only a minority of studies (67/168, 36%), which used a total of 21 distinct bleeding outcome reporting schemes. A plurality of adult studies used the WHO Bleeding Scale and a plurality of pediatric studies used the Buchanan and Adix Score, Figure 2. HRQoL Outcomes. HRQoL outcomes were reported in a small minority of studies (15/168, 9%), which used a total of 8 different HRQoL instruments (6 adult instruments and 2 pediatric instruments), Table. Conclusions: Despite prior attempts to standardize evaluation of platelet response to treatment in ITP, there remains wide variability in the definition of both treatment response and remission. In particular, most prospective and randomized studies published following release of the 2009 IWG report have used study-specific platelet count response thresholds, whereas retrospective observational studies were much more likely to adopt the IWG-recommended platelet response definitions. Despite the fact that ITP is a bleeding disorder and its impact on HRQoL has been well-documented, most ITP studies published in the past decade did not evaluate bleeding in any systematic way and fewer still evaluated the impact of treatment on HRQoL. Further standardization of platelet count, bleeding, and HRQoL outcomes in both pediatric and adult ITP is greatly needed, especially for future randomized trials, to allow for more meaningful comparison of response rates and efficacy between studies. Disclosures Al-Samkari: Agios: Consultancy, Research Funding; Argenx: Consultancy; Amgen: Research Funding; Dova: Consultancy, Research Funding; Rigel: Consultancy. Arnold:Novartis: Consultancy, Research Funding; Amgen: Consultancy, Research Funding; Bristol Myers Squibb: Research Funding; Rigel: Consultancy; Principia: Consultancy. Grace:Novartis: Research Funding; Dova: Membership on an entity's Board of Directors or advisory committees; Pfizer: Research Funding; Agios: Research Funding.

Efficacy and Safety of Intravenous Efgartigimod 10 Mg/Kg in Adult Patients with Primary Immune Thrombocytopenia: Advance, a Phase 3 Clinical Trial in Progress

Efficacy and Safety of Intravenous Efgartigimod 10 Mg/Kg in Adult Patients with Primary Immune Thrombocytopenia: Advance, a Phase 3 Clinical Trial in Progress

Durability of Initial Platelet Count Response in Patients Treated with Avatrombopag for Immune Thrombocytopenia (ITP): Post-Hoc Results from a Phase 3 Clinical Study

Background: The clinical management of ITP has been evolving. Thrombopoietin receptor agonists (TPO-RAs) have become widely utilized as subsequent treatments, and the 2019 ASH guidelines recommend their use over rituximab to achieve a durable response. TPO-RAs eltrombopag (ELT) and romiplostim (ROMI) have been FDA approved for over a decade with a well demonstrated efficacy profile. ELT, an oral medication, must be administered two hours prior to or four hours after meals containing polyvalent cations such as calcium or magnesium to mitigate clinically relevant effects on the pharmacokinetic profile (ELT prescribing information). Additionally, ELT carries a boxed warning for hepatoxicity that requires monitoring. ROMI, an injectable, is typically administered in a health care practitioner's office weekly which may be challenging for some patients (Pts). Avatrombopag (AVA) is an oral TPO-RA approved in 2019 for Pts with ITP. In clinical trials, AVA rapidly increased platelet count (PC) (5 days) and maintained it in the target range (50 to 150×109/L) with chronic dosing. Further, it has an exposure-adjusted safety profile generally comparable to placebo with no boxed warning for hepatotoxicity. AVA does not chelate polyvalent cations; therefore, it is administered with food and without restrictions regarding meal composition. A high proportion of Pts (~90%) respond to AVA; but limited information is available regarding the durability of response over time utilizing clinically relevant loss of response definitions. Aims: To understand the duration of initial response with AVA and the overall percent of treatment days a response level PC was achieved in responding Pts. Methods: A 6-month, multicenter, randomized, double-blind, Phase 3 study enrolled 32 AVA and 17 placebo-treated Pts with ITP. The study design included a 6-week study drug titration period, 12-week concomitant ITP medication reduction period, and an 8-week maintenance period. The primary endpoint was the median number of cumulative weeks of PC response (PC ≥50,000/µL) over the course of the study without rescue medication. Pts receiving rescue medication during the study were deemed to be non-responders for the remainder of the study. For this post-hoc analysis, we analyzed how many days it took for responding AVA Pts (n=29) to experience their first loss of response (LOR) or reach core study conclusion. After the initial PC ≥50,000/µL was noted, we also examined the percentage of remaining treatment time that initial response was maintained. Response was defined as the first time achieving a PC ≥50,000/µL. LOR was defined as a Pt experiencing a PC <30,000/µL for 4 consecutive weeks (LOR-4wk), or in a more conservative manner, Pts experiencing a PC <30,000/µL on 2 consecutive scheduled visits (LOR-2vis) [visits were weekly or biweekly depending on the phase of the study with 21 visits occurring over 26 weeks]. When a LOR was observed, the date of the first PC <30,000/µL was used for subsequent calculations with a return of response defined as a PC exceeding ≥30,000/µL again. Pts who required rescue therapy (n=6) were included in the analyses and the first date of administration was used for the LOR date. Pts requiring either corticosteroids (n=4) or IVIg (n=1) as rescue therapy were considered non-responders for a minimum of 8 weeks and Pts receiving a platelet transfusion (n=1) for a minimum of 1 week. Results: 72.4% (21/29) and 55.2% (16/29) of AVA responsive Pts never experienced a LOR-4wk or LOR-2vis, respectively. The median number of days until responding Pts experienced their first LOR-4wk, discontinued treatment, or completed the 6-month study was 170 (mean 134.7) and 146 (mean 119.1) for the LOR-2vis analysis. Pts maintained their initial response on average for 87.7% (median 100%) of their remaining time in the study for LOR-4wk and 84.5% (median 100%) for LOR-2vis analyses, with Pts often losing response only briefly when noted. Pts requiring rescue therapy often returned to a response level PC and remained in the 6-month study for approximately 5 months following their initial response. Conclusions: These data suggest that the initial response to AVA is stable and durable with up to 72.4% of Pts never experiencing a LOR, even with the planned objective of reducing the use of baseline concomitant ITP medications during the study. In those pts experiencing a LOR, many ended up achieving response level PCs again without a subsequent LOR. Disclosures Wojdyla: Dova Pharmaceuticals: Current Employment. Vredenburg:Dova Pharmaceuticals: Current Employment. Jamieson:Dova Pharmaceuticals: Current Employment. Gernsheimer:Amgen Corporation: Consultancy, Honoraria; Novartis: Consultancy; Cellphire: Consultancy; Rigel Corporation: Consultancy, Research Funding; Principia: Research Funding; Sanofi: Consultancy; Vertex: Consultancy; Dova Pharmaceuticals: Consultancy.

Fibrosis-4 index as a predictor for mortality in hospitalised patients with COVID-19: a retrospective multicentre cohort study

ObjectiveThe reliable risk factors for mortality of COVID-19 has not evaluated in well-characterised cohort. This study aimed to identify risk factors for in-hospital mortality within 56 days in patients with...

Parameter Estimation and Hypothesis Testing of Multivariate Poisson Inverse Gaussian Regression

Multivariate Poisson regression is used in order to model two or more count response variables. The Poisson regression has a strict assumption, that is the mean and the variance of response variables are equal (equidispersion). Practically, the variance can be larger than the mean (overdispersion). Thus, a suitable method for modelling these kind of data needs to be developed. One alternative model to overcome the overdispersion issue in the multi-count response variables is the Multivariate Poisson Inverse Gaussian Regression (MPIGR) model, which is extended with an exposure variable. Additionally, a modification of Bessel function that contain factorial functions is proposed in this work to make it computable. The objective of this study is to develop the parameter estimation and hypothesis testing of the MPIGR model. The parameter estimation uses the Maximum Likelihood Estimation (MLE) method, followed by the Newton–Raphson iteration. The hypothesis testing is constructed using the Maximum Likelihood Ratio Test (MLRT) method. The MPIGR model that has been developed is then applied to regress three response variables, i.e., the number of infant mortality, the number of under-five children mortality, and the number of maternal mortality on eight predictors. The unit observation is the cities and municipalities in Java Island, Indonesia. The empirical results show that three response variables that are previously mentioned are significantly affected by all predictors.

Distribution-free regression model selection with a nested spatial correlation structure

In spatial regression analysis, a suitable specification of the mean regression model is crucial for unbiased analysis. Also, to enhance statistical efficiency of the mean regression analysis, we need to suitably account for the underlying spatial correlation structure. In this paper, we focus on selection of an appropriate mean model in spatial regression analysis under a general anisotropic nested correlation structure considered in Adegboye et al. (2018). We propose a distribution-free model selection criterion, called the Spatial Information Criterion (SIC), which is an estimate of the weighted mean squared error for predicting the response variable, and relies on assumptions only for the first two moments of the spatial response data. The simulations under the settings of covariate selection reveal that the SIC performs well for covariate selection in the mean model regardless of the correlation structure is nested/non-nested (multi-source or not), isotropic/anisotropic (direction-dependent or not). Also, the SIC accommodates both continuous and count response data. We illustrate the utility of the proposed method by a real data application concerning the predictive regression model for the fine particulate matter (PM2.5) concentration.

Fitting prediction rule ensembles to psychological research data: An introduction and tutorial.

Prediction rule ensembles (PREs) are a relatively new statistical learning method, which aim to strike a balance between predictive performance and interpretability. Starting from a decision tree ensemble, like a boosted tree ensemble or a random forest, PREs retain a small subset of tree nodes in the final predictive model. These nodes can be written as simple rules of the form if [condition] then [prediction]. As a result, PREs are often much less complex than full decision tree ensembles, while they have been found to provide similar predictive performance in many situations. The current article introduces the methodology and shows how PREs can be fitted using the R package pre through several real-data examples from psychological research. The examples also illustrate a number of features of package pre that may be particularly useful for applications in psychology: support for categorical, multivariate and count responses, application of (non)negativity constraints, inclusion of confirmatory rules and standardized variable importance measures. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Caplacizumab induces fast and durable platelet count responses with improved time to complete remission and recurrence-free survival in patients with acquired thrombotic thrombocytopenic purpura

Caplacizumab induces fast and durable platelet count responses with improved time to complete remission and recurrence-free survival in patients with acquired thrombotic thrombocytopenic purpura

Immunomodulatory Efficiency of Abelmoschus esculentus in Swiss Albino Mice

Background: Immunomodulation through natural or synthetic substances may be considered as an alternative for prevention and cure of infections. Methods: A total of nineteen groups of Swiss albino mice were experimented for immunological studies with an inclusion of control and immunised control. Lymphocyte count and DTH response in the experimental groups after the administration of plant drugs. The result showed remarkable changes in all kind of treated animals when compared to control. The increment in ‘B’ and “T lymphocyte number was much pronounced in mice by the administration of A. esculentus in combination with immuno-enhansive drug. Result: In DTH responses directly correlated with cell mediated immunity and were found to be highest at the maximum dose (100 mg/Kg) of plant extracts A. esculuntus. From the results it was clear that the plant extract induced immunomodulating potential of the test animal. On administration of plant extract an enhanced and visible DTH responses were observed.

Developing a goodness of fit test for a joint model of clustered survival and count data

Mixed responses within clusters are becoming an increasingly popular phenomenon. However, this scenario is a complex one. This research is based on survival and count response data which occur frequently in medical studies. In the literature, there is no satisfactory goodness of fit test for a joint model of these two responses within a cluster setting. Therefore, the main objective of this study is to develop a GOF test for this scenario. Simulation studies were used to examine the type I error rate and the power of the test. An example was used to display the practicality of the test.

Conway–Maxwell–Poisson regression models for dispersed count data

AbstractWhile Poisson regression serves as a standard tool for modeling the association between a count response variable and explanatory variables, it is well‐documented that this approach is limited by the Poisson model's assumption of data equi‐dispersion. The Conway–Maxwell–Poisson (COM‐Poisson) distribution has demonstrated itself as a viable alternative for real count data that express data over‐ or under‐dispersion, and thus the COM‐Poisson regression can flexibly model associations involving a discrete count response variable and covariates. This work overviews the ongoing developmental knowledge and advancement of COM‐Poisson regression, introducing the reader to the underlying model (and its considered reparametrizations) and related regression constructs, including zero‐inflated models, and longitudinal studies. This manuscript further introduces readers to associated computing tools available to perform COM‐Poisson and related regressions.This article is categorized under: Statistical Models > Linear Models Statistical Models > Generalized Linear Models

Platelet count trends and response to fondaparinux in a cohort of heparin-induced thrombocytopenia suspected patients after pulmonary endarterectomy.

A definitive diagnosis of heparin-induced thrombocytopenia (HIT) is difficult to make, especially in patients undergoing cardiac surgery. In this retrospective cohort study, we assessed the platelet count trends and the response to fondaparinux in a population of patients of suspected HIT after pulmonary endarterectomy (PEA). Patients enrolled in this study were over the age of 18years, and survived longer than 7days after PEA between January 1, 2011 and December 31, 2015. HIT likelihood was assessed by the 4T's score and interpreted by our institutional algorithm. 54 patients were operated, and 49 patients met the inclusion criteria. Six patients met the criteria for suspected HIT and were treated with fondaparinux until the platelet recovered. No significant difference was observed of clinical characteristics between intermediate to high HIT likelihood patients (HIT SUSPECTED) and low HIT likelihood patients (NO HIT SUSPECTED). HIT SUSPECTED patients reached platelet count lowest later (about 5.5days after PEA), while NO HIT SUSPECTED patients is about 4.0days after PEA. Percentage of platelet counts decrease (> 50%) was larger than NO HIT SUSPECTED patients (< 50%). There was no difference in mortality or residual pulmonary hypertension between HIT SUSPECTED and NO HIT SUSPECTED patients. Two HIT SUSPECTED patients who used heparin after PEA died, the other four survived by replacing heparin or low molecular weight heparin with fondaparinux. Suspected HIT patients should be surveilled carefully. Platelet counts trends may have some hints in the prevention of HIT. Fondaparinux may be effective for patients with suspected HIT.