The Basic Four Measures and their Derivates in Dichotomous Diagnostic Tests
Tadeusz R Ostrowski, MD and Tadeusz Ostrowski, PhD
Article Type: Original Article | First Published: June 05, 2020
The paper focuses on four basic statistics of dichotomous diagnostic tests, i.e. sensitivity, specificity, positive and negative predictive value, and some of their derivates, like Youden index and predictive summary index, and on further derivates of these derivates, i.e. Matthews correlation coefficient (or Yule phi), chi squared test and Cramer’s V coefficient. The paper contains also the necessary and sufficient conditions for a test to be invalid, to be uninformative and the necessary con...
Factors Influencing Resident Research: Evidence from a 10-Year Cohort
Adnan N Kiani, Babatunde Olaiya, Richard Berg and Ateeq Rehman
Article Type: Research Article | First Published: March 19, 2020
ACGME has put great emphasis on scholarly activity during residency, yet ACGME has not been able to identify gaps in achieving these goals. We possess longitudinal data for the last 10 years across our residency training programs. With this, we have identified missing gaps as well as propose interventions to address gaps. The research design employs utilizing a standardized research instrument (questionnaire), answered by every resident at the onset and completion of residency training. This que...
Nonparametric Method for Estimation of Controlled Correlations in Studies of VEGF-Hypoxia Relationship
Maxim S Kodryan, Anna V Kuznetsova, Luidmila L Klimenko, Aksana N Mazilina, Ivan V Baskakov and Oleg V Senko
Article Type: Research Article | First Published: March 04, 2020
It is known that vascular endothelial growth factor (VEGF) expression is a response to hypoxia. On the other hand hypoxia may be detected by oximetry parameters including venous CO-oximetry indices or corresponding partial pressures of O2 and CO2. However significant correlation ties between VEGF levels and oximetry parameters were not found in groups of patients with ischemic stroke and transient ischemic attack. At that some effect related to the relationship between VEGF and sO2 was observed ...
A Signal Detection Analysis of World Health Organization’s Pharmacovigilance Database
Article Type: Original Article | First Published: December 14, 2019
Pharmacovigilance is the primary method used to identify hazards associated with medicinal products. Using generalized likelihood ratio tests, we examed the adverse reaction signals of the drug class Monoamine oxidase inhibitors (MAOIs) from World Health Organization’s Pharmacovigilance Database. The proposed test procedure has the ability of detecting adverse reactions of multiple drugs simultaneously. Our findings sugggest there are 23 common Adverse reaction signals detected within this dru...
Child Mortality: A Comparative Study of Some Developing Countries in the World
Ilker Etikan, Ogunjesa Babatope, Kabiru Bala and Savas Ilgi
Article Type: Research Article | First Published: September 30, 2019
According to the United Nations Sustainable Development Goals, countries all over the world are expected to create a healthy living environment for the populace most especially the vulnerable population of which children are examples. Despite the reducing trend in the under-five mortality rate in some developing nations, some nations still have a high record of under-five mortality. This study adopted the use of a One-way Analysis of Variance (ANOVA) to evaluate any significant difference in the...
Partial Variable Selection and its Applications in Biostatistics
Jingwen Gu, Ao Yuan, Chunxiao Zhou, Leighton Chan and Ming T Tan
Article Type: Research Article | First Published: April 14, 2018
We propose and study a method for partial covariates selection, which only select the covariates with values fall in their effective ranges. The coefficients estimates based on the resulting data is more interpretable based on the effective covariates. This is in contrast to the existing method of variable selection, in which some variables are selected/deleted in whole. To test the validity of the partial variable selection, we extended the Wilks theorem to handle this case. Simulation studies ...