scholarly journals Effective use of the McNemar test

2020 ◽  
Vol 74 (11) ◽  
Author(s):  
Matilda Q. R. Pembury Smith ◽  
Graeme D. Ruxton
Keyword(s):  
Null Hypothesis ◽  
Biological Research ◽  
Future Research ◽  
Binomial Data ◽  
Mcnemar Test ◽  
Null Hypothesis Testing ◽  
Current Usage ◽  
Chi Squared ◽  
Effective Use ◽  
Effective Analysis

Abstract It is not uncommon for researchers to want to interrogate paired binomial data. For example, researchers may want to compare an organism’s response (positive or negative) to two different stimuli. If they apply both stimuli to a sample of individuals, it would be natural to present the data in a 2 × 2 table. There would be two cells with concordant results (the frequency of individuals which responded positively or negatively to both stimuli) and two cells with discordant results (the frequency of individuals who responded positively to one stimulus, but negatively to the other). The key issue is whether the totals in the two discordant cells are sufficiently different to suggest that the stimuli trigger different reactions. In terms of the null hypothesis testing paradigm, this would translate as a P value which is the probability of seeing the observed difference in these two values or a more extreme difference if the two stimuli produced an identical reaction. The statistical test designed to provide this P value is the McNemar test. Here, we seek to promote greater and better use of the McNemar test. To achieve this, we fully describe a range of circumstances within biological research where it can be effectively applied, describe the different variants of the test that exist, explain how these variants can be accessed in R, and offer guidance on which of these variants to adopt. To support our arguments, we highlight key recent methodological advances and compare these with a novel survey of current usage of the test. Significance statement When analysing paired binomial data, researchers appear to reflexively apply a chi-squared test, with the McNemar test being largely overlooked, despite it often being more appropriate. As these tests evaluate a different null hypothesis, selecting the appropriate test is essential for effective analysis. When using the McNemar test, there are four methods that can be applied. Recent advice has outlined clear guidelines on which method should be used. By conducting a survey, we provide support for these guidelines, but identify that the method chosen in publications is rarely specified or the most appropriate. Our study provides clear guidance on which method researchers should select and highlights examples of when this test should be used and how it can be implemented easily to improve future research.

scholarly journals Determinants of Managed Entry Agreements in the context of Health Technology Assessment: a comparative analysis of oncology therapies in four countries

2021 ◽  
Vol 37 ◽  
Author(s):  
Olina Efthymiadou ◽  
Panos Kanavos
Keyword(s):  
Decision Making ◽  
Health Technology Assessment ◽  
Technology Assessment ◽  
Best Practice ◽  
Health Technology ◽  
Future Research ◽  
Best Practice Guidelines ◽  
Chi Squared ◽  
Decision Making Factors ◽  
Managed Entry Agreements

Abstract Background Managed Entry Agreements (MEAs) are increasingly used to address uncertainties arising in the Health Technology Assessment (HTA) process due to immature evidence of new, high-cost medicines on their real-world performance and cost-effectiveness. The literature remains inconclusive on the HTA decision-making factors that influence the utilization of MEAs. We aimed to assess if the uptake of MEAs differs between countries and if so, to understand which HTA decision-making criteria play a role in determining such differences. Methods All oncology medicines approved since 2009 in Australia, England, Scotland, and Sweden were studied. Four categories of variables were collected from publicly available HTA reports of the above drugs: (i) Social Value Judgments (SVJs), (ii) Clinical/Economic evidence submitted, (iii) Interpretation of this evidence, and (iv) Funding decision. Conditional/restricted decisions were coded as Listed With Conditions (LWC) other than an MEA or LWC including an MEA (LWCMEA). Cohen's κ-scores measured the inter-rater agreement of countries on their LWCMEA outcomes and Pearson's chi-squared tests explored the association between HTA variables and LWCMEA outcomes. Results A total of 74 drug-indication pairs were found resulting in n = 296 observations; 8 percent (n = 23) were LWC and 55 percent (n = 163) were LWCMEA. A poor-to-moderate agreement existed between countries (−.29 < κ < .33) on LWCMEA decisions. Cross-country differences within the LWCMEA sample were partly driven by economic uncertainties and largely driven by SVJs considered across agencies. Conclusions A set of HTA-related variables driving the uptake of MEAs across countries was identified. These findings can be useful in future research aimed at informing country-specific, “best-practice” guidelines for successful MEA implementation.

INTRODUCTORY STATISTICS COURSE TERTIARY STUDENTS’ UNDERSTANDING OF P-VALUES

2014 ◽  
Vol 13 (1) ◽  
pp. 53-65 ◽  
Author(s):  
ROBYN REABURN
Keyword(s):  
Null Hypothesis ◽  
Probabilistic Reasoning ◽  
Statistics Education ◽  
Introductory Statistics ◽  
P Values ◽  
Testing Procedures ◽  
Research Journal ◽  
Null Hypothesis Testing ◽  
Statistics Course ◽  
Teaching Programs

This study aimed to gain knowledge of students’ beliefs and difficulties in understanding p-values, and to use this knowledge to develop improved teaching programs. This study took place over four consecutive teaching semesters of a one-semester tertiary statistics unit. The study was cyclical, in that the results of each semester were used to inform the instructional design for the following semester. Over the semesters, the following instructional techniques were introduced: computer simulation, the introduction of hypothetical probabilistic reasoning using a familiar context, and the use of alternative representations. The students were also encouraged to write about their work. As the interventions progressed, a higher proportion of students successfully defined and used p-values in Null Hypothesis Testing procedures. First published May 2014 at Statistics Education Research Journal Archives

Abstract P724: Perimenopausal Women With Migraine Present With Stroke at a Younger Age and With Less Comorbid Diabetes

Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Morgan Figurelle ◽  
Dawn M Meyer ◽  
Emily Perrinez ◽  
Karen Rapp ◽  
Rebecca Wells ◽  
...  
Keyword(s):  
Native American ◽  
Ischemic Stroke ◽  
Menopausal Status ◽  
Hot Flashes ◽  
Future Research ◽  
Significant Difference ◽  
Perimenopausal Women ◽  
Chi Squared ◽  
Night Sweats ◽  
Comprehensive Stroke Center

Introduction: Migraine is an independent risk factor for ischemic stroke. Frequency and severity increases in the perimenopausal period accompanied by marked vasomotor symptoms (VMS) such as hot flashes, flushing and night sweats. There is emerging evidence that VMS increases the risk of vascular disease including stroke. The purpose of this study was describe the demographics and co-morbidities of perimenopausal females with and without migraine that experience acute ischemic stroke (AIS). Methods: In this IRB approved study, electronic health record (EHR) data was obtained from a large, academic, comprehensive stroke center from 1/1/2015 to 1/1/2020. Inclusion criteria included female sex, age 42-65 years, and hospital diagnosis code of AIS. Hemorrhagic stroke, TIA, vasculopathy, and endocarditis associated strokes were excluded. Perimenopause was defined as age ≥42 and ≤65 years. Hormonal and menopausal status was not available in the EHR. We compared the baseline demographics and co-morbidities by ICD10 codes of subjects with and without migraine. Chi squared was used to compare categorical data and t test for continuous. Spearman rho was used to assess correlations. Results: We identified 660 subjects who met study criteria (n=83 with migraine; n=577 without migraine). Migraine positive subjects were significantly younger (mean age 58 vs 66 years, p=0.03) at time of AIS. Migraine positive subjects identified significantly more often as White (47%) compared to Black (10%), Asian (7%), Pacific Islander (1%), Native American/Alaskan (1%), Other/Mixed Race (31%), and unknown (3%), p=0.001. There was no significant difference in Hispanic ethnicity (p=0.87), hypertension (p=0.66), hyperlipidemia (p=0.12), or atrial fibrillation (p=0.84). Comorbid diabetes was significantly higher in the non-migraine group (94% vs 6%, p<0.001). Conclusion: Perimenopausal women with concomitant history of migraine present with AIS at younger ages and with lower rates of diabetes than those without a migraine history. Future research must be done to assess the correlation of menopausal symptom severity, hormone levels at time of AIS, and stroke characteristics to further understand the role of menopause in stroke risk.

scholarly journals Independent Searching During One-Shot Information Literacy Instruction Sessions: Is It an Effective Use of Time?

2012 ◽  
Vol 7 (4) ◽  
pp. 52 ◽  
Author(s):  
Rebekah Willson
Keyword(s):  
Information Literacy ◽  
Literacy Instruction ◽  
Search Time ◽  
Research Process ◽  
Future Research ◽  
Pedagogical Practice ◽  
Class Time ◽  
Information Literacy Instruction ◽  
Thesis Statement ◽  
Effective Use

Objective – To test the assumption that giving students time to research independently during a one-shot information literacy instruction (ILI) session, combined with scaffolding, is an effective pedagogical practice and a good use of class time. Methods – The study was conducted at a student-focused, four-year undergraduate institution with 8,500 full load equivalent students. Following brief, focused instruction in 10 different ILI sessions, first-, second-, and third-year students in 80-minute one-shot ILI sessions were given time to research independently. The librarian and instructor were present to scaffold the instruction students received. Students were asked to track the research they did during class using a research log and to fill out a short Web survey about their preparedness to do research and the usefulness of the ILI session. Results – Students agreed to have 83 research logs and 73 Web surveys included in the study. Students indicated that they felt more prepared to do research for their assignment after the ILI session and rated individual help from the librarian as the most useful aspect of the instruction session. Students did not rate independent time to do research as valuable as anticipated. Examining the research logs indicated that several things are taking place during the ILI session, including that students are demonstrating what was taught in the session in their searches, that their searches are progressing in complexity, and that students are using feedback from previous searches to inform the formulation of search queries. While students appear to be putting independent search time to good use, many students’ articulation of their thesis statement remains poor and searches continue to be fairly simplistic. Conclusions – This study gives evidence that giving independent research time in ILI sessions, with scaffolding, is an effective use of class time. The study also demonstrates that the majority of students are able to use what is taught during classes and that they are using class time effectively, though searching remains fairly simple. The focus of ILI sessions is on skill development, and future research should be on integrating IL into the curriculum to develop more complex skills and thinking needed in the research process.

Impact of Biases in the False-Positive Rate on Null Hypothesis Testing

Epilepsy ◽  
2011 ◽  
pp. 241-248
Author(s):  
Ralph Andrzejak ◽  
Daniel Chicharro ◽  
Florian Mormann
Keyword(s):  
Hypothesis Testing ◽  
False Positive ◽  
Null Hypothesis ◽  
False Positive Rate ◽  
Null Hypothesis Testing ◽  
Positive Rate

scholarly journals 'Strategy-as-practice' by hospital personnel in hospitals: a scoping review protocol

2021 ◽  
Vol 4 ◽  
pp. 26
Author(s):  
Carolyn Donohoe ◽  
Kate Frazer ◽  
Diarmuid Stokes ◽  
Thilo Kroll
Keyword(s):  
Scoping Review ◽  
Scientific Evidence ◽  
The Body ◽  
Future Research ◽  
Hospital Personnel ◽  
Use Of Resources ◽  
Strategic Process ◽  
Review Protocol ◽  
Strategy As Practice ◽  
Effective Use

Background: Strategy in hospitals is based on distinct principles and rules which lead organisations to act on chosen priorities. Hospitals are struggling to cope with increasing service demands and activity and need to become more responsive to changing environments while demonstrating effective use of resources. Strategizing involves the active process of sensing, planning, implementing and evaluating strategy. Strategy-as-practice is concerned with what people do about strategy in an organisation, as opposed to the traditional focus on what the organisation has as a strategy. It is recognised that there is a disconnection between strategic planning and implementation, however little is known about how organisational context influences the strategic process or how hospital personnel engage in strategic activities. The aim of this scoping review is to explore the literature on strategizing by hospital personnel in hospitals, and will include literature for hospital both professional and managerial backgrounds, to establish the extent and breadth of strategizing or as it is often termed ‘strategy-as-practice’ in hospitals. Methods: The systematic scoping review will search the literature within the databases of PubMed, Embase, CINAHL, PsycINFO, ABI/INFORM (Proquest) and OpenGrey.net to explore the scientific evidence on strategizing in hospitals. The review will be based on the Arksey & O’Malley (2005) framework of five mandatory steps which was updated (Levac et al 2010, Colquhoun et al 2014 & Peters 2015) and is published online by the Joanna Briggs Institute. It will follow the PRISMA-ScP reporting guidelines. Conclusion: A scoping review methodology will provide a framework to explore strategizing in hospitals comprehensively and map the body of literature for this subject, which has not been conducted previously. This review will summarise the evidence on the use of strategy as practice in hospitals.  Based on the findings we will identify knowledge gaps and areas for future research.

Applications of Data Mining in Software Development Life Cycle

2014 ◽  
pp. 67-79
Author(s):  
Naveen Dahiya ◽  
Vishal Bhatnagar ◽  
Manjeet Singh ◽  
Neeti Sangwan
Keyword(s):  
Data Mining ◽  
Life Cycle ◽  
Software Development ◽  
Future Research ◽  
Data Mining Techniques ◽  
Use Of Data ◽  
Development Life Cycle ◽  
Efficient Information ◽  
Software Development Life Cycle ◽  
Effective Use

Data mining has proven to be an important technique in terms of efficient information extraction, classification, clustering, and prediction of future trends from a database. The valuable properties of data mining have been put to use in many applications. One such application is Software Development Life Cycle (SDLC), where effective use of data mining techniques has been made by researchers. An exhaustive survey on application of data mining in SDLC has not been done in the past. In this chapter, the authors carry out an in-depth survey of existing literature focused towards application of data mining in SDLC and propose a framework that will classify the work done by various researchers in identification of prominent data mining techniques used in various phases of SDLC and pave the way for future research in the emerging area of data mining in SDLC.

Success Factors in the Implementation of a Collaborative Technology and Resulting Productivity Improvements in a Small Business

2005 ◽  
pp. 129-150
Author(s):  
Nory B. Jones ◽  
Thomas R. Kochtanek
Keyword(s):  
Decision Making ◽  
Success Factors ◽  
Future Research ◽  
Collaborative Technology ◽  
Performance Improvements ◽  
Effective Implementation ◽  
Potential Success ◽  
Effective Use ◽  
The Impact ◽  
The Relationship

Practitioners and academics often assume that investments in technology will lead to productivity improvements. While the literature provides many examples of performance improvements resulting from adoption of different technologies, there is little evidence demonstrating specific, generalizable factors that contribute to these improvements. Furthermore, investment in technology does not guarantee effective implementation. This qualitative study examined the relationship between four classes of potential success factors on the adoption of a collaborative technology and whether they were related to performance improvements in a small service company. Users of a newly adopted collaborative technology were interviewed to explore which factors contributed to their initial adoption and subsequent effective use of this technology. The results show that several factors were strongly related to adoption and effective implementation. The impact on performance improvements was further explored. Results showed a qualitative link to several performance improvements including timesavings and improved decision-making. These results are discussed in terms of generalizability as well as suggestions for future research.

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