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Nevin Manimala Statistics

Preparation and Curation of Multiyear, Multilocation, Multitrait Datasets

Methods Mol Biol. 2022;2481:83-104. doi: 10.1007/978-1-0716-2237-7_6.

ABSTRACT

Genome-wide association studies (GWAS) are a powerful approach to dissect genotype-phenotype associations and identify causative regions. However, this power is highly influenced by the accuracy of the phenotypic data. To obtain accurate phenotypic values, the phenotyping should be achieved through multienvironment trials (METs). In order to avoid any technical errors, the required time needs to be spent on exploring, understanding, curating and adjusting the phenotypic data in each trial before combining them using an appropriate linear mixed model (LMM). The LMM is chosen to minimize as much as possible any effect that can lead to misestimation of the phenotypic values. The purpose of this chapter is to explain a series of important steps to explore and analyze data from METs used to characterize an association panel. Two datasets are used to illustrate two different scenarios.

PMID:35641760 | DOI:10.1007/978-1-0716-2237-7_6

Categories
Nevin Manimala Statistics

Interpretation of Manhattan Plots and Other Outputs of Genome-Wide Association Studies

Methods Mol Biol. 2022;2481:63-80. doi: 10.1007/978-1-0716-2237-7_5.

ABSTRACT

With increasing marker density, estimation of recombination rate between a marker and a causal mutation using linkage analysis becomes less important. Instead, linkage disequilibrium (LD) becomes the major indicator for gene mapping through genome-wide association studies (GWAS). In addition to the linkage between the marker and the causal mutation, many other factors may contribute to the LD, including population structure and cryptic relationships among individuals. As statistical methods and software evolve to improve statistical power and computing speed in GWAS, the corresponding outputs must also evolve to facilitate the interpretation of input data, the analytical process, and final association results. In this chapter, our descriptions focus on (1) considerations in creating a Manhattan plot displaying the strength of LD and locations of markers across a genome; (2) criteria for genome-wide significance threshold and the different appearance of Manhattan plots in single-locus and multiple-locus models; (3) exploration of population structure and kinship among individuals; (4) quantile-quantile (QQ) plot; (5) LD decay across the genome and LD between the associated markers and their neighbors; (6) exploration of individual and marker information on Manhattan and QQ plots via interactive visualization using HTML. The ultimate objective of this chapter is to help users to connect input data to GWAS outputs to balance power and false positives, and connect GWAS outputs to the selection of candidate genes using LD extent.

PMID:35641759 | DOI:10.1007/978-1-0716-2237-7_5

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Nevin Manimala Statistics

Genome-Wide Association Study Statistical Models: A Review

Methods Mol Biol. 2022;2481:43-62. doi: 10.1007/978-1-0716-2237-7_4.

ABSTRACT

Statistical models are at the core of the genome-wide association study (GWAS). In this chapter, we provide an overview of single- and multilocus statistical models, Bayesian, and machine learning approaches for association studies in plants. These models are discussed based on their basic methodology, cofactors adjustment accounted for, statistical power and computational efficiency. New statistical models and machine learning algorithms are both showing improved performance in detecting missed signals, rare mutations and prioritizing causal genetic variants; nevertheless, further optimization and validation studies are required to maximize the power of GWAS.

PMID:35641758 | DOI:10.1007/978-1-0716-2237-7_4

Categories
Nevin Manimala Statistics

Designing a Genome-Wide Association Study: Main Steps and Critical Decisions

Methods Mol Biol. 2022;2481:3-12. doi: 10.1007/978-1-0716-2237-7_1.

ABSTRACT

In this introductory chapter, we seek to provide the reader with a high-level overview of what goes into designing a genome-wide association study (GWAS) in the context of crop plants. After introducing some general concepts regarding GWAS, we divide the contents of this overview into four main sections that reflect the key components of a GWAS: assembly and phenotyping of an association panel, genotyping, association analysis and candidate gene identification. These sections largely reflect the structure of the chapters which follow later in the book, and which provide detailed discussions of these various steps. In each section, in addition to providing external references from the literature, we also often refer the reader to the appropriate chapters in this book in which they can further explore a topic. We close by summarizing some of the key questions that a prospective user of GWAS should answer prior to undertaking this type of experiment.

PMID:35641755 | DOI:10.1007/978-1-0716-2237-7_1

Categories
Nevin Manimala Statistics

Preparation and Curation of Phenotypic Datasets

Methods Mol Biol. 2022;2481:13-27. doi: 10.1007/978-1-0716-2237-7_2.

ABSTRACT

Based on case studies, in this chapter we discuss the extent to which the number and identity of quantitative trait loci (QTL) identified from genome-wide association studies (GWAS) are affected by curation and analysis of phenotypic data. The chapter demonstrates through examples the impact of (1) cleaning of outliers, and of (2) the choice of statistical method for estimating genotypic mean values of phenotypic inputs in GWAS. No cleaning of outliers resulted in the highest number of dubious QTL, especially at loci with highly unbalanced allelic frequencies. A trade-off was identified between the risk of false positives and the risk of missing interesting, yet rare alleles. The choice of the statistical method to estimate genotypic mean values also affected the output of GWAS analysis, with reduced QTL overlap between methods. Using mixed models that capture spatial trends, among other features, increased the narrow-sense heritability of traits, the number of identified QTL and the overall power of GWAS analysis. Cleaning and choosing robust statistical models for estimating genotypic mean values should be included in GWAS pipelines to decrease both false positive and false negative rates of QTL detection.

PMID:35641756 | DOI:10.1007/978-1-0716-2237-7_2

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Nevin Manimala Statistics

Predictive Ability of Multiple Mini-Interviews in Admissions on Programmatic Academic Achievement: A Systematic Review

J Allied Health. 2022 Summer;51(2):154-159.

ABSTRACT

BACKGROUND: Multiple mini-interviews (MMI) are emerging as the preferred interview format for admittance to health professions training programs.

OBJECTIVE: Evaluate the evidence regarding MMI as a predictor of programmatic academic achievement in graduate health professions train¬ing programs.

METHODS: Using the PRISMA method, two literature searches on PubMed and Google Scholar of publications from 2004-2019 were completed, identifying 7 unique references pertinent to the review’s objective. Head-to-head comparative analysis was completed between articles that had similar outcomes in addition to cumulative analysis of all included studies.

RESULTS: Of the 7 articles included in this systematic review, all had at least one statistically significant correlation between MMI used for admissions and programmatic academic achievement in graduate health professions training programs. Outcomes assessed were highly variable and included specific assessments, cumulative program GPA, and clinical performance. Studies from four unique health professions–dentistry, medicine, physician associate, and pharmacy–were included in the review.

CONCLUSIONS: Evidence indicates that MMI are an effective, valid, and reliable admissions interview format to identify future programmatic academic achievement of graduate health professions training students in specific scenarios. A head-to-head analysis comparing MMI with more traditional interview formats, particularly on an entire pool of qualified applicants, would be beneficial to assess for superiority.

PMID:35640296

Categories
Nevin Manimala Statistics

Measuring Medical Documentation Accuracy: A Novel Approach Offering Reproducible Objective Measurements Across Educational Levels and Documentation Style

J Allied Health. 2022 Summer;51(2):149-153.

ABSTRACT

Medical documentation is an important component of healthcare delivery and represents a significant portion of physician assistant educational efforts. Assessing proficiency in documentation is challenging, often relying on the subjective evaluation of documents. This study presents a novel approach using video-recorded provider-patient interactions and an interactive scoring rubric. Sixty-five participants, representing three cohorts, completed medical documentation with each document receiving accuracy scores from three independent scorers. Using this approach, the consistency of two versions of a provider-patient encounter with the same chief complaint but variable details was demonstrated (p = 0.239). Inter-scorer reliability using this method was maintained across participants with an average variation of 1.21 points on a 54-point scale between three independent scorers. Applying this method to evaluate educational preparedness, a statistically significant increase in accuracy was identified in cohorts approaching the completion of didactic education (p < 0.05). The method presented here provides a reliable platform to access medical documentation accuracy across educational levels and documentation styles.

PMID:35640295

Categories
Nevin Manimala Statistics

The Anatomy Glove Learning System for Hand Anatomy and Function: Use of Embodied Learning in Occupational Therapy Education

J Allied Health. 2022 Summer;51(2):143-148.

ABSTRACT

Occupational therapy students must build a solid foundation in hand anatomy to prepare for practice that includes interventions for people with hand injuries or impairments. To engage students in effective active learning, the Anatomy Glove Learning System (AGLS) was used in two entry-level occupational therapy programs. This cloth glove with imprinted bones was worn while students followed an online video series to draw the muscles and tendons on the hand and understand hand physiology. Research exploring student gains in hand anatomy knowledge and confidence at the two universities (n=199) over a 2-year period found statistically significant improvements in 12 of 15 items and in total scores of an anatomy quiz taken as a pre-test and post-test (t(198)=13.77, p<0.001, Cohen’s d = 1.142). In addition, statistically significant differences in student confidence related to hand anatomy (t(110)=24.47, p<0.01) and student reports of positive experiences were identified after using the AGLS. This active learning system utilized a form of embodied learning to facilitate preparedness for entry-level practice of occupational therapy students to address the needs of clients with hand impairments. Future research focused on the student experience may determine additional insights into the full benefits of the AGLS and similar active learning strategies regarding hand anatomy and physiology.

PMID:35640294

Categories
Nevin Manimala Statistics

Online Learning During the COVID-19 Pandemic: Comparing the Perceptions of Domestic and International Occupational Therapy Students

J Allied Health. 2022 Summer;51(2):121-129.

ABSTRACT

PURPOSE: To investigate differences between domestic and international occupational therapy students in their perceptions and experiences of online learning during the COVID-19 pandemic.

METHODS: Cross-sectional study of 151 occupational therapy students enrolled in the 4-year Bachelor of Occupational Therapy (Honours) courses at the University of Canberra and Monash University in Australia. Students completed the Student Engagement in the e-Learning Environment Scale (SELES) and the Distance Education Learning Environment Scale (DELES). Both instruments have established validity and reliability. ANOVA analysis with bootstrapping was completed to examine potential differences in domestic and international students’ experiences and perceptions of online learning.

RESULTS: Statistically significant differences were observed between domestic and international students’ scores on the DELES Student Autonomy (p=0.001), Personal Relevance (p=0.001) and Student Interaction and Collaboration (p=0.037) subscales.

CONCLUSION: International students experienced greater difficulties during online learning in relation to taking control of their own learning, connecting acquired knowledge with real-world settings, and forging collaborative and interactive working relationships with their peers. Academic, technological, and social support measures are recommended to strengthen students’ self-directed learning skills, facilitate them to link what they have learned beyond online settings, and encourage active and collaborative engagement with peers and instructors.

PMID:35640291

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Nevin Manimala Statistics

Effectiveness of 7-Valent Pneumococcal Conjugate Vaccine Against Invasive Pneumococcal Disease in Medically At-Risk Children in Australia: A Record Linkage Study

J Pediatric Infect Dis Soc. 2022 May 30:piac038. doi: 10.1093/jpids/piac038. Online ahead of print.

ABSTRACT

BACKGROUND: Children with chronic medical conditions are at higher risk of invasive pneumococcal disease (IPD), but little is known about the effectiveness of the primary course of pneumococcal conjugate vaccine (PCV) in these children.

METHODS: A cohort born in 2001-2004 from two Australian states and identified as medically at-risk (MAR) of IPD either using ICD-coded hospitalizations (with conditions of interest identified by 6 months of age) or linked perinatal data (for prematurity) were followed to age 5 years for notified IPD by serotype. We categorized fully vaccinated children as either receiving PCV dose 3 by <12 months of age or ≥1 PCV dose at ≥12 months of age. Cox proportional hazard modeling was used to estimate hazard ratios (HRs), adjusted for confounders, and vaccine effectiveness (VE) was estimated as (1-HR) × 100.

RESULTS: A total of 9220 children with MAR conditions had 53 episodes of IPD (43 vaccine-type); 4457 (48.3%) were unvaccinated and 4246 (46.1%) were fully vaccinated, with 1371 (32.3%) receiving dose 3 by 12 months and 2875 (67.7%) having ≥1 dose at ≥12 months. Estimated VE in fully vaccinated children was 85.9% (95% CI: 33.9-97.0) against vaccine-type IPD and 71.5% (95% CI: 26.6-88.9) against all-cause IPD.

CONCLUSION: This is the first population-based study evaluating the effectiveness of PCV in children with MAR conditions using record linkage. Our study provides evidence that the VE for vaccine-type and all-cause IPD in MAR children in Australia is high and not statistically different from previously reported estimates for the general population. This method can be replicated in other countries to evaluate VE in MAR children.

PMID:35640283 | DOI:10.1093/jpids/piac038