Comparison of Two or More Correlated AUCs in Paired Sample Design

Purpose of study Methods of comparing the accuracy of diagnostic tests are of increasing necessity in biomedical science. When a test result is measured on a continuous scale, an assessment of the performance of the overall value of the test can be made using the Receiver Operating Characteristic (ROC) curve. This curve describes the discrimination ability of a diagnosis test in terms of diseased subjects from non-diseased subjects. The area under the ROC curve (AUC) describes the probability that a randomly chosen diseased subject will have higher probability of having disease than a randomly chosen non-diseased subject. For comparing two or more diagnostic test results, the difference between AUCs is often used. This paper proposes a non-parametric alternative method of comparing two or more correlated area under the curve (AUCs) of diagnostic tests for paired sample data. This method is based on Chi-square test statistic. Methods This paper investigated both parametric and non-parametric methods of comparing the equality of two AUCs and proposed a Chi-square test for the comparison of two or more diagnostic test processes. The proposed method does not require the knowledge of true status of subjects or gold standard in evaluating the accuracy of tests unlike other existing methods. The proposed method is most suitable for paired sample design. It also offers reliable statistical inferences even in small sample problems and circumvent the difficulties of deriving the statistical moments of complex summary statistics as seen in the Delong method. The proposed method provides for further analysis to determine the possible reason for rejecting the null hypothesis of equality of AUCs. Results The proposed method when applied on real data, avoids the lengthy and more difficult procedures of estimating the variances of two AUCs as a way of determining if two AUCs differ significantly. The method is validated using the Cochran Q test and was shown to compare favourably. The proposed method recommended for comparing two or more correlated AUCs when the data is paired. It is simple and does not require prior knowledge of true status of subjects unlike other existing methods. Keywords: Chi-square test, Cochran Q test, cut-off value, area under the curve, receiver operating characteristic, Dichotomous data DOI: 10.7176/JNSR/9-9-06 Publication date:May 31st 201

Estimation of AUC for Assessing Its Significance in Classification Models

The assessment of the performance of a diagnostic test when test results are measured on continuous scale can be evaluated using the measures of sensitivity and specificity over the range of possible cut-off points for the predictor variable. This is achieved by the use of a receiver operating characteristic (ROC) curve which is a graph of sensitivity against 1-specificity across all possible decision cut-offs values from a diagnostic test result. This curve evaluates the diagnostic ability of tests to discriminate the true state of subjects especially in classification models. These tasks of assessing the predictive accuracy of classification models is always better achieved using a summary measure of accuracy across all possible ranges of cut-off values called the area under the receiver operating characteristic curve (AUC). In this paper, we propose a simple nonparametric method of calculating AUC from predicted probability of positive response involving multiple prediction rules. This method is based on the knowledge of non-parametric Mann-Whitney U statistic. Based on the predicted outcomes and observed outcomes, the performance of diagnostic tests is assessed for the classification models through the AUC calculated from these outcomes. The proposed method when applied on real data, the significance of AUC for the classification models is assessed. The method offers reliable statistical inferences and circumvents the difficulties of deriving the statistical moments of complex summary statistics seen in the parametric method. The proposed method as a non-parametric estimation is recommended for calculating the AUC as it compares favorably with the existing parametric and non-parametric methods.    Keywords: Cut-off value, ROC, Predicted probability, parametric, non-parametric DOI: 10.7176/JNSR/9-9-03 Publication date:May 31st 201

Moments of Continuous Bi-Variate Distributions: An Alternative Approach

We propose a method of obtaining the moment of some continuous bi-variate distributions with parameters........

Review of the Statistical Techniques in Medical Sciences

Medical scientists often times are faced with the need to choose the right statistical technique for a given set of data. There are a number of criteria that should be a guide in making the right choice: the research questions, the category of the variables involved the size of the sample, the scale of measurement of the variable, the type of study design, among others. This article reviews some procedures which will be followed by any medical researcher in selecting the appropriate statistical techniques. Of course, all statistical techniques have certain underlying assumptions, which must be checked before the technique is applied. Keywords: Variable, Prospective Studies, Retrospective Studies, Statistical significanceBio-Research Vol. 6 (1) 2008: pp. 311-31

Bayes’ theorem: A paradigm research tool in biomedical sciences

One of the most interesting applications of the results of probability theory involves estimating unknown probability and making decisions on the basis of new (sample) information. Biomedical scientists often use the Bayesian decision theory for the purposes of computing diagnostic values such as sensitivity and specificity for a certain diagnostic test and from which positive or negative predictive values are obtained in other to make decisions concerning the well-being of the patient. Often times error rates are encountered and estimated from the results of trials of the screening test with a view to calculating the overall case rate for which an accurate estimate is rarely available. The concept of conditional probability takes into account information about the occurrence of one event to predict the probability of another event. It is on this premise that this article presents Bayes’ theorem as a vital tool. A brief intuitive development of this theorem and its application in diagnosis is given with minimum proof and examples

Animated film as a catalyst for child-centered education: The Kings and Queens Nursery and Primary School Nkpor experience.

One of the major objectives of education is to focus on the individual child’s development and the impact on society. For this reason, it is necessary to consider the techniques and forms of teaching from pre-schools to higher schools. Traditional, which is the old method of imparting knowledge appears weak and insufficient to match the changes of our time. Therefore, the problem of this study is to evaluate the traditional teaching technique and its limited pedagogic impact in the face of geometric digitization of the contemporary society. The active use of media technique, specifically, animated film, is considered a method that will help children move from passivity to active learning. This study aims at evaluating the potentials of animated film as a catalyst for child-centered education. It is set to find out the extent to which animated film can stimulate effective child-centered education, using The Honest Girl as a case study. This work is based on the ReuvenFeuerstein’s Mediated Learning Experience Theory. The theory emphasizes that the learner’s needs and abilities are the central issue of planning and achieving effective classroom instruction. The researcher adopted qualitative methodological approach for this research since it involved collection of qualitative data from a sample that was drawn from a given population. The findings showed that a strong participatory method of teaching like animated media, when used effectively, will take care of bringing out the children’s potentials more than traditional method. The study recommends that animations be properly linked to existing curriculum as a vital medium of imparting knowledge to children to help improve the quality and standard of education in Nigeria and inculcate cultural identities and values to young children. This study concluded that educators are not to do away completely with traditional teaching techniques but instead to update their current style of teaching to include animated technique

ASSESSMENT OF THE KNOWLEDGE AND ATTITUDE OF MOTHERS TOWARDS POSTPARTUM DEPRESSION IN SELECTED SAGAMU COMMUNITY HEALTH CENTERS, OGUN STATE. A CROSS-SECTIONAL STUDY.

Background Postpartum depression (PPD) is of significant public health concern due to the alarming prevalence and adverse consequences among women globally. This study assessed the knowledge and attitudes of mothers towards postpartum depression in selected health care centers in Sagamu community health centers in Ogun State.  Methods The study utilized a cross-sectional quantitative design. 152 women were selected for the study, a researcher-developed questionnaires were used to collect data from respondents. SPSS version 25 was used for data analysis, and descriptive and inferential statistics were used to present the findings of the study.  Results Findings from the study revealed that most of the respondents 40.8% were between the ages of 21-25 years old. The majority (66.4%) of the respondents were knowledgeable about postpartum depression and only 58.5% of the respondents indicated a positive attitude toward postpartum depression. Stressful life events during the postpartum period, financial difficulties, sleep deprivation, and traumatic birth experiences were identified as factors responsible for PPD having over 80%. Furthermore, findings also revealed that there is a relationship between the knowledge and attitude of mothers towards postpartum depression (r=0.516, p-values=0.000).  Conclusion In conclusion, mothers in the two selected Sagamu community health centers had a high level of knowledge and only about half had positive attitudes towards the knowledge of PPD.  Recommendation There should be an increase in awareness of postpartum depression by healthcare providers among mothers, especially during antenatal visits to reduce stigma and promote help-seeking behavior to improve maternal and child health. Moreover, partners and family members can support and encourage women dealing with postpartum depression.

Tafsir Al-Qur'an, attr.to Abdullah b. Abbas (d.68/668)

This research is an analytical study and an edition of Sürat al-Fätiha and Sürat al-Baqara from a copy of the manuscript that is the tafsir ascribed to Ibn `Abbas according to the transmission of al-Kalbi from Abü Sälih. Historians reckon some ninety-eight copies of this manuscript exist, some complete and others partial commentaries, as mentioned in the Fahras al-Shimil. I have relied upon the main copy extant at Markaz Juma ` al-Mäjid, Dubai, cross-referencing it against three separate manuscripts and the printed Tanwir al- Migbäs. The study concludes that the text is neither the authorship nor the direct narration of Ibn `Abbas but is likely to be the work of al-Kalbi. This is based on a careful and detailed presentation of the life of Ibn `Abbas, his knowledge, his scholarship in exegesis, the sources upon which he relied for his exegesis, methodology and the aspects and subjects he treated therein; The aim of this chapter is to ascertain what the probability is of the edited text being the work of Ibn `Abbas, the probability that al-Kalbi has transmitted it from him, and if not, then is it correct to posit that al-Kalbi is its author ? Also, the life of al-Kalb-i, his works in tafsir, his style, methodology and his contributions to the field of exegesis. Also the study concludes that the printed Tanwir al-Migbäs is the same in transmission, with some differences in words order or commentaries with the other manuscripts, we used in this study. I have divided the study into two parts: an analytical study of the text and edition. The study includes a biography of Ibn `Abbas covering his social and intellectual life in order to ascertain whether there is any truth in the ascription of the manuscript to him. There is also an account of the life of al-Kalbi, the alleged reporter of this tafsir, and the one who ascribes it to Ibn `Abbas, covering similar aspects as that for Ibn `Abbas, in order to shed some light on whether there is a possibility that he is the author of the manuscript. R , ere is also a comparative study on some aspects that appear in the manuscript with other books in tafsir. After this I undertake an analytical study of the manuscript to clarify its methodology in tafsTr by way of presenting the sources of tafsir it uses and the subjects it covers along with its style. Also included are the characteristics of the manuscript with a conclusion covering the results found. The second part of this study is an edition of al-Fätiha and al-Baqara taken from the manuscript and in Arabic. The edition involved the following: inserting of grammatical inflections to verses of the Qur'än and numbering, writing of the verses in a font (Kufic script) differentiating them from the rest of the text, referencing of hadith from their sources, the inserting of grammatical inflections on unusual or unclear words and an explanation of their meanings, correction of typographical errors, indications of variant readings of verses if required, biographies of personalities and the identification of countries, places and tribes

Breastfeeding and the mother–child relationship: A case study of Ebonyi State University Teaching Hospital, Abakaliki

Background: The relationship between a mother and child is extremely important, especially with regard to breastfeeding habits. These affect the lives of children and mothers at an early stage and have become a source of concern for health workers and non-professionals alike. Objectives: This study was aimed at determining the relationships that exist between a mother and child and various breastfeeding habits. Method: The primary method of data collection was the design and use of a comprehensive questionnaire, which was distributed to women at the post-natal unit of the Gynaecology Department of Ebonyi State University Teaching Hospital in Abakaliki, Nigeria (EBSUTHAI). These women were civil servants, traders, students and housewives. A simple random sampling procedure of data collection was adopted in selecting the sample of 190 women. A chi-square method of analysis was used to test for independence of association. A 5% level of significance was considered. Results: At a 5% level of significance, a significant relationship existed between the category/occupation of mothers and the time intervals at which mothers breastfed their children (χ2cal= 20.53). Given the same level, exclusive breastfeeding was found to be dependent on a woman’s occupation (χ2cal= 8.49); however, at the same significance level, analysis showed that there was a significant relationship between a mother’s decision to feed her child breast milk as well as semi-solid food and those who chose to breastfeed exclusively (χ2cal= 12.168). No significant relationship (χ2cal= 3.14) was found in determining whether children who are fed breast milk only are more intelligent than children who are fed semi-solid food as well. Conclusion: Mothers were expected to breastfeed their children at will because the time intervals at which they should breastfeed were not fixed. It seems that breastfeeding does not determine the intelligence of a child. Although it is generally recommended that mothers should practise exclusive breastfeeding, the findings of this study suggested that mothers should be equally recommended to alternate between feeding their children both semi-solid food and breast milk and breast milk exclusively, because a significant relationship exists between a mother’s decision to feed breast milk and semi-solid food as well as breastfeeding exclusively

In vitro evaluation of the interaction between tea extracts and penicillin G against staphylococcus aureus

The herb-drug interaction between tea (Carmelia sinensis) extract and penicillin G (Pen G) was investigated against three strains of Staphylococcus aureus using pair combinations in an in vitro decimal assay for additivity test. Results showed that the interactions between penicillin G and teaextracts were mainly additive against the three strains of S. aureus. This suggests that the concomitant administration of tea and Pen G may not impair the antimicrobial activity of Pen G