Syed Mustafa Ali

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A General Class of Coefficients of Divergence of One Distribution from Another

1966-01-01

Summary Let p1 and p2 be two probability measures on the same space and let φ be the generalized Radon-Nikodym derivative of p2 with respect to p1. If C is … Summary Let p1 and p2 be two probability measures on the same space and let φ be the generalized Radon-Nikodym derivative of p2 with respect to p1. If C is a continuous convex function of a real variable such that the p1-expectation (generalized as in Section 3) of C(φ) provides a reasonable coefficient of the p1-dispersion of φ, then this expectation has basic properties which it is natural to demand of a coefficient of divergence of p2 from p1. A general class of coefficients of divergence is generated in this way and it is shown that various available measures of divergence, distance, discriminatory information, etc., are members of this class.

Association between Random Variables and the Dispersion of a Radon–Nikodym Derivative

1965-01-01

Syed Mustafa Ali , S. D. Silvey

Summary In a previous paper by one of the authors (Silvey, 1964) it was suggested that the Radon–Nikodym derivative of the joint distribution of two, not necessarily real-valued, random variables … Summary In a previous paper by one of the authors (Silvey, 1964) it was suggested that the Radon–Nikodym derivative of the joint distribution of two, not necessarily real-valued, random variables with respect to the product of their marginal distributions provides the analytic key for discussing association between the random variables. In this paper we shall develop this point and lend some support to the suggestion by proving that in the case of normal random vectors the distribution of this derivative, as determined by the product of the marginal distributions, becomes more widely spread out as association between the vectors increases. More precisely we shall show that the expected value of any continuous convex function of the derivative is a non-decreasing function of each of the canonical correlation coefficients between the two vectors.

A Further Result on the Relevance of the Dispersion of a Radon–Nikodym Derivative to the Problem of Measuring Association

1965-01-01

Syed Mustafa Ali , S. D. Silvey

Summary Let x and y be jointly distributed random variables (not necessarily real-valued) and let φ be the Radon–Nikodym derivative of their joint distribution with respect to the product of … Summary Let x and y be jointly distributed random variables (not necessarily real-valued) and let φ be the Radon–Nikodym derivative of their joint distribution with respect to the product of their marginal distributions. If x′ and y′ are functions of x and y respectively and φ′ is a corresponding derivative for x′ and y′, then the dispersion of φ, as determined by the product of the marginal distributions of x and y, is not less than that of φ′, this being true in the strongest possible sense.

Measuring management’s perspective of data quality in Pakistan’s Tuberculosis control programme: a test-based approach to identify data quality dimensions

2018-01-16

Syed Mustafa Ali , Naveed Anjum , Maged N. Kamel Boulos +3 more

Data quality is core theme of programme's performance assessment and many organizations do not have any data quality improvement strategy, wherein data quality dimensions and data quality assessment framework are … Data quality is core theme of programme's performance assessment and many organizations do not have any data quality improvement strategy, wherein data quality dimensions and data quality assessment framework are important constituents. As there is limited published research about the data quality specifics that are relevant to the context of Pakistan's Tuberculosis control programme, this study aims at identifying the applicable data quality dimensions by using the 'fitness-for-purpose' perspective. Forty-two respondents pooled a total of 473 years of professional experience, out of which 223 years (47%) were in TB control related programmes. Based on the responses against 11 practical cases, adopted from the routine recording and reporting system of Pakistan's TB control programme (real identities of patient were masked), completeness, accuracy, consistency, vagueness, uniqueness and timeliness are the applicable data quality dimensions relevant to the programme's context, i.e. work settings and field of practice. Based on a 'fitness-for-purpose' approach to data quality, this study used a test-based approach to measure management's perspective and identified data quality dimensions pertinent to the programme and country specific requirements. Implementation of a data quality improvement strategy and achieving enhanced data quality would greatly help organizations in promoting data use for informed decision making.

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The current state of digital manikins to support pain self-reporting: a systematic literature review

2025-05-06

Syed Mustafa Ali , D. Mountain , Rebecca Rachael Lee +5 more

Abstract This systematic literature review aimed to explore the current state of digital manikins to support pain self-reporting and to explore the extent to which manikins had progressed along the … Abstract This systematic literature review aimed to explore the current state of digital manikins to support pain self-reporting and to explore the extent to which manikins had progressed along the translational pathway. We systematically searched six electronic databases using a combination of key words and MeSH terms for “pain” and “manikin” to identify original studies in English that used a digital pain manikin for collecting information from adults with any condition. We extracted and descriptively synthesised data on the characteristics of studies and digital pain manikins and mapped them to a stage of the translational pathway (ie, design, testing, metric validation, and diffusion). We screened 6,189 articles, of which we included 104. Articles reported on 31 unique digital pain manikins. Most studies were conducted in Europe (n = 60; 58%), recruited people with pain/painful conditions (n = 69; 66%) from clinical settings (n = 67; 64%). Of the 31 manikins, the majority were two-dimensional (n = 21; 68%) with a front and back body view (n = 18; 58%) and allowed users to draw their pain on any area of the manikin (n = 23; 74%). Most manikins were still in the development and testing stages (n = 23; 74%). Only eight (26%) had progressed fully through the translational pathway, taking between 7 and 20 years to go from early development to diffusion. We found a substantial number of mostly two-dimensional digital pain manikins reported on in the last decade. However, most were still at early stages of the translational pathway, with only few having progressed through to diffusion into research and health care settings.

Designing an Equitable Text Messaging Service for South Asians to Manage Hypertension: Understanding Gender Norms

2025-05-15

Syed Mustafa Ali , Sabine N van der Veer

Hypertension is prevalent among South Asians (SAs). A culturally adapted text messaging service can help manage hypertension, for which understanding gender norms is important in the cultural context of SAs. … Hypertension is prevalent among South Asians (SAs). A culturally adapted text messaging service can help manage hypertension, for which understanding gender norms is important in the cultural context of SAs. Therefore, this study aimed to understand gender norms to design an equitable text messaging service to support management of hypertension. We conducted two focus group discussions and four in-depth interviews, which were transcribed verbatim and analysed to draw themes: (a) existing gender norms and caring responsibilities; and (b) motivation and confidence in managing hypertension. This study has elaborated why role of family carers should be strengthened by designing a text messaging service for South Asians.

Clinical utility of digital pain drawings captured by people living with musculoskeletal pain conditions: a qualitative study

2025-05-16

Syed Mustafa Ali , S H Elsayed , Rebecca Rachael Lee +4 more

Digital pain drawings are an emerging method for pain assessment, but it is still unclear how these could best support pain treatment and management decisions. Therefore, this study explored the … Digital pain drawings are an emerging method for pain assessment, but it is still unclear how these could best support pain treatment and management decisions. Therefore, this study explored the potential clinical utility of digital pain drawings. We conducted a narrative study, involving qualitative interviews with healthcare professionals providing pain management services to people living with musculoskeletal pain conditions working across different disciplines and care levels in the healthcare system of the United Kingdom. We transcribed interviews, conducted thematic content analysis to identify themes and presented results using a framework approach. We interviewed three general practitioners, five rheumatology healthcare professionals, four physiotherapists, two pain consultants and one rheumatology nurse. We identified four themes describing current pain assessment practices, potential advantages of digital pain drawings either alone or in combination with other pain information (e.g. perceived pain triggers and relieving factors) and outcome measures (e.g. quality of sleep, function and anxiety). Digital pain drawings provide an opportunity of enriching patient-provider communication, particularly for people with language barriers. Digital pain drawings may also support healthcare professionals across different disciplines and care levels (e.g. primary and secondary care) in decisions related to referrals, differential diagnosis, treatment planning, evaluating response to treatment and scheduling follow-up visits when combining pain drawings with other pain information, such as pain consequences and perceived causes. Digital pain drawings are clinically useful because of their potential to guide diagnosis, treatment and management choices in managing musculoskeletal chronic pain. Future research should investigate how these potential benefits are achieved by integrating digital pain drawings in clinical practice across different disciplines and care levels in the UK's healthcare system and beyond.

Clinical utility of digital pain drawings captured by people living with musculoskeletal pain conditions: a qualitative study

2025-05-16

Syed Mustafa Ali , S H Elsayed , Rebecca Rachael Lee +4 more

Designing an Equitable Text Messaging Service for South Asians to Manage Hypertension: Understanding Gender Norms

2025-05-15

Syed Mustafa Ali , Sabine N van der Veer

The current state of digital manikins to support pain self-reporting: a systematic literature review

2025-05-06

Syed Mustafa Ali , D. Mountain , Rebecca Rachael Lee +5 more

Measuring management’s perspective of data quality in Pakistan’s Tuberculosis control programme: a test-based approach to identify data quality dimensions

2018-01-16

Syed Mustafa Ali , Naveed Anjum , Maged N. Kamel Boulos +3 more

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A General Class of Coefficients of Divergence of One Distribution from Another

1966-01-01

Syed Mustafa Ali , S. D. Silvey

A Further Result on the Relevance of the Dispersion of a Radon–Nikodym Derivative to the Problem of Measuring Association

1965-01-01

Syed Mustafa Ali , S. D. Silvey

Association between Random Variables and the Dispersion of a Radon–Nikodym Derivative

1965-01-01

Syed Mustafa Ali , S. D. Silvey

Coauthor	Papers Together
Sabine N van der Veer	3
S. D. Silvey	3
Rebecca Rachael Lee	2
William G Dixon	2
S H Elsayed	1
Ghulam Haider	1
Javariya Aamir	1
Maged N. Kamel Boulos	1
D Murphy	1
Naveed Anjum	1
Jill Firth	1
D. Mountain	1
Alessandro Chiarotto	1
H. D. McCarthy	1
Muhammad Ishaq	1
David Wong	1

Association between Random Variables and the Dispersion of a Radon–Nikodym Derivative

1965-01-01

Syed Mustafa Ali , S. D. Silvey

Association between Random Variables and the Dispersion of a Radon–Nikodym Derivative

1965-09-01

S. M. Ali , S. D. Silvey

Testing Statistical Hypotheses

2021-01-07

E. L. Lehmann

This chapter presents the basic concepts and results of the theory of testing statistical hypotheses. The generalized likelihood ratio tests that are discussed can be applied to testing in the … This chapter presents the basic concepts and results of the theory of testing statistical hypotheses. The generalized likelihood ratio tests that are discussed can be applied to testing in the presence of nuisance parameters. Besides the likelihood ratio tests, for testing in the presence of nuisance parameters one can use conditional tests. The chapter also presents the motivation for steps of the proof of the randomization principle theorem. It considers the case of a single observation, but the extension to the case of n observations will be obvious. The chapter presents an approach that requires unbiasedness and explains how the theory of testing statistical hypotheses is related to the theory of confidence intervals. It reviews the major testing procedures for parameters of normal distributions and is intended as a convenient reference for users rather than an exposition of new concepts or results.

An Introduction to Multivariate Statistical Analysis

1986-01-01

Robb J. Muirhead , T. W. Anderson

Preface to the Third Edition.Preface to the Second Edition.Preface to the First Edition.1. Introduction.2. The Multivariate Normal Distribution.3. Estimation of the Mean Vector and the Covariance Matrix.4. The Distributions and … Preface to the Third Edition.Preface to the Second Edition.Preface to the First Edition.1. Introduction.2. The Multivariate Normal Distribution.3. Estimation of the Mean Vector and the Covariance Matrix.4. The Distributions and Uses of Sample Correlation Coefficients.5. The Generalized T2-Statistic.6. Classification of Observations.7. The Distribution of the Sample Covariance Matrix and the Sample Generalized Variance.8. Testing the General Linear Hypothesis: Multivariate Analysis of Variance9. Testing Independence of Sets of Variates.10. Testing Hypotheses of Equality of Covariance Matrices and Equality of Mean Vectors and Covariance Matrices.11. Principal Components.12. Cononical Correlations and Cononical Variables.13. The Distributions of Characteristic Roots and Vectors.14. Factor Analysis.15. Pattern of Dependence Graphical Models.Appendix A: Matrix Theory.Appendix B: Tables.References.Index.

On a Measure of Association

1964-09-01

S. D. Silvey

The problem of obtaining a satisfactory measure of association between two random variables is closely allied to that of obtaining a measure of the amount of information about one contained … The problem of obtaining a satisfactory measure of association between two random variables is closely allied to that of obtaining a measure of the amount of information about one contained in the other. For the more closely associated are the random variables the more information about one ought to be given by an observation on the other and vice versa. It is not, therefore, surprising to find that there have been several suggestions for basing coefficients of association on the now celebrated measure of information introduced by Shannon [9] in the context of communication theory. (See Bell [1] for certain of these and for references to others). Now Shannon's measure of information was based on the notion of entropy which seems to be much more meaningful for finite probability spaces than it is for infinite spaces, and while Gel'fand and Yaglom [2] have suggested a generalisation of Shannon's measure for infinite spaces, there remain difficulties, as indicated by Bell [1], about deriving from it coefficients of association or dependence between random variables taking infinite sets of values. In the present paper, by adopting a slightly different attitude to information from that of communication theory, we shall obtain a general measure of information which yields a fairly natural coefficient of dependence between two continuous random variables or, more generally, between two non-atomic measures. The next section provides the motivation for the introduction of this measure of information and a general definition is given in Section 3. In Section 4 we discuss some of the properties of this measure regarded as a coefficient of association along the lines suggested by Renyi [8]. Finally, in Section 5, we indicate the relevance of this measure to estimation theory.

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Introduction to Multivariate Statistical Analysis.

1959-05-01

William G. Madow , T. W. Anderson

Advanced Statistical Methods In Biometric Research

1952-01-01

C. Radhakrishna Rao

A Measure of Asymptotic Efficiency for Tests of a Hypothesis Based on the sum of Observations

1952-12-01

Herman Chernoff

In many cases an optimum or computationally convenient test of a simple hypothesis $H_0$ against a simple alternative $H_1$ may be given in the following form. Reject $H_0$ if $S_n … In many cases an optimum or computationally convenient test of a simple hypothesis $H_0$ against a simple alternative $H_1$ may be given in the following form. Reject $H_0$ if $S_n = \sum^n_{j=1} X_j \leqq k,$ where $X_1, X_2, \cdots, X_n$ are $n$ independent observations of a chance variable $X$ whose distribution depends on the true hypothesis and where $k$ is some appropriate number. In particular the likelihood ratio test for fixed sample size can be reduced to this form. It is shown that with each test of the above form there is associated an index $\rho$. If $\rho_1$ and $\rho_2$ are the indices corresponding to two alternative tests $e = \log \rho_1/\log \rho_2$ measures the relative efficiency of these tests in the following sense. For large samples, a sample of size $n$ with the first test will give about the same probabilities of error as a sample of size $en$ with the second test. To obtain the above result, use is made of the fact that $P(S_n \leqq na)$ behaves roughly like $m^n$ where $m$ is the minimum value assumed by the moment generating function of $X - a$. It is shown that if $H_0$ and $H_1$ specify probability distributions of $X$ which are very close to each other, one may approximate $\rho$ by assuming that $X$ is normally distributed.