## Medical Statistics at a Glance, Second Edition (At a Glance) 2nd Edition

Medical Statistics at a Glance provides a concise and accessible introduction and revision aid for undergraduate medical students and anyone wanting a straightforward introduction to this complex subject.

*Get ebook : $10.00 *

Following the familiar, easy-to-use at a Glance format, each topic is presented as a double-page spread with key facts accompanied by clear, informative tables, formulae and graphs.

This new edition of Medical Statistics at a Glance:

- Contains a second colour throughout to enhance the visual appeal, making the subject even easier to understand
- Features worked examples on each topic, with emphasis on computer analysis of data rather than hand calculations
- Includes new topics on Rates and Poisson regression, Generalised linear models, Explanatory variables in statistical models and Regression models for clustered data.
- Has an accompanying website
__http://www.medstatsaag.com/__containing supplementary material including multiple choice questions (MCQs) with annotated answers for self-assessment

Medical Statistics at a Glance will appeal to all medical students, junior doctors and researchers in biomedical and pharmaceutical disciplines.

Reviews of the last edition

“All medical professionals will come across statistics in their daily work and so a proper understanding of these concepts is invaluable. This is brought to you in this easily comprehensible succinct textbook.

.I unreservedly recommend this book to all medical students, especially those that dislike reading reams of text. This is one book that will not sit on your shelf collecting dust once you have graduated and will also function as a reference book.”

*4th Year Medical Student. Barts and the London Chronicle, Spring 2003,
vol.5, issue 1*

**Medical Statistics at a Glance, Second Edition (At a Glance) ****2nd Edition**

by

ISBN-13: 978-1405127806

ISBN-10: 9781405127806

**Medical Statistics at a Glance, Second Edition (At a Glance) ****2nd Edition – Content**

Handling data

1 Types of data 8

2 Data entry 10

3 Error checking and outliers 12

4 Displaying data graphically 14

5 Describing data: the ‘average’ 16

6 Describing data: the ‘spread’ 18

7 Theoretical distributions: the Normal distribution 20

8 Theoretical distributions: other distributions 22

9 Transformations 24

Sampling and estimation

10 Sampling and sampling distributions 26

11 Confidence intervals 28

Study design

12 Study design I 30

13 Study design II 32

14 Clinical trials 34

15 Cohort studies 37

16 Case–control studies 40

Hypothesis testing

17 Hypothesis testing 42

18 Errors in hypothesis testing 44

Basic techniques for analysing data

Numerical data

19 Numerical data: a single group 46

20 Numerical data: two related groups 49

21 Numerical data: two unrelated groups 52

22 Numerical data: more than two groups 55

Categorical data

23 Categorical data: a single proportion 58

24 Categorical data: two proportions 61

25 Categorical data: more than two categories 64

Regression and correlation

26 Correlation 67

27 The theory of linear regression 70

28 Performing a linear regression analysis 72

29 Multiple linear regression 76

30 Binary outcomes and logistic regression 79

31 Rates and Poisson regression 82

32 Generalized linear models 86

33 Explanatory variables in statistical models 88

34 Issues in statistical modelling 91

Important considerations

35 Checking assumptions 94

36 Sample size calculations 96

37 Presenting results 99

Additional chapters

38 Diagnostic tools 102

39 Assessing agreement 105

40 Evidence-based medicine 108

41 Methods for clustered data 110

42 Regression methods for clustered data 113

43 Systematic reviews and meta-analysis 116

44 Survival analysis 119

45 Bayesian methods 122

Appendix

A Statistical tables 124

B Altman’s nomogram for sample size calculations 131

C Typical computer output 132

D Glossary of terms 144

Index 153

**Medical Statistics at a Glance, Second Edition (At a Glance) ****2nd Edition – Preface**

Medical Statistics at a Glance is directed at undergraduate medical students, medical researchers, postgraduates in the biomedical disciplines and at pharmaceutical industry personnel. All of these individuals will, at some time in their professional lives, be faced with quantitative results (their own or those of others) which will need to be critically evaluated and interpreted, and some, of course, will have to pass that dreaded statistics exam! A proper

understanding of statistical concepts and methodology is invaluable for these needs. Much as we should like to fire the reader with an enthusiasm for the subject of statistics, we are pragmatic.

Our aim in this new edition, as it was in the earlier edition, is to provide the student and the researcher, as well as the clinician encountering statistical concepts in the medical literature, with a book which is sound, easy to read, comprehensive, relevant, and of useful practical application. We believe Medical Statistics at a Glance will be particularly helpful as an adjunct to statistics lectures and as a reference guide.

The structure of this second edition is the same as that of the first edition. In line with other books in the At a Glance series, we lead the reader through a number of self-contained two-, three- or occasionally four-page chapters, each covering a different aspect of medical statistics. We have learned from our own teaching experiences, and have taken account of the difficulties that our students have encountered when studying medical statistics. For this reason,

we have chosen to limit the theoretical content of the book to a level that is sufficient for understanding the procedures involved, yet which does not overshadow the practicalities of their execution.

Medical statistics is a wide-ranging subject covering a large number of topics. We have provided a basic introduction to the underlying concepts of medical statistics and a guide to the most commonly used statistical procedures. Epidemiology is closely allied to medical statistics. Hence some of the main issues in epidemiology, relating to study design and interpretation, are discussed. Also included are chapters which the reader may find useful only occasionally, but which are, nevertheless, fundamental to many areas of medical research; for example, evidence-based medicine, systematic reviews and meta-analysis, survival analysis and Bayesian methods. We have explained the principles underlying these topics so that the reader will be able to understand and interpret the results from them when they are presented in the literature.

The order of the first 30 chapters of this edition corresponds to that of the first edition. Most of these chapters remain unaltered in this new edition: some have relatively minor changes which accommodate recent advances, cross-referencing or re-organization of the new material. Our major amendments relate to comparatively

complex forms of regression analysis which are now more widely used than at the time of writing the first edition, partly because the associated software is more accessible and efficient than in the past.

We have modified the chapter on binary outcomes and logistic regression (Chapter 30), included a new chapter on rates and Poisson regression (Chapter 31) and have considerably expanded the original statistical modelling chapter so that it now comprises three chapters, entitled ‘Generalized linear models (Chapter 32), ‘Explanatory variables in statistical models’ (Chapter 33) and ‘Issues in statistical modelling’ (Chapter 34). We have also modified Chapter 41 which describes different approaches to the analysis of clustered data, and added Chapter 42 which outlines the various regression methods that can be used to analyse this type of data.

The first edition had a brief description of time series analysis which we decided to omit from this second edition as we felt that it was probably too limited to be of real use, and expanding it would go beyond the bounds of our remit. Because of this omission and the chapters that we have added, the numbering of the chapters in the second edition differs from that of the first edition after Chapter 30.

Most of the chapters in this latter section of the book which were also in the first edition are altered only slightly, if at all. The description of every statistical technique is accompanied by an example illustrating its use. We have generally obtained the data for these examples from collaborative studies in which we or colleagues have been involved; in some instances, we have used real data from published papers. Where possible, we have used the same

data set in more than one chapter to reflect the reality of data analysis which is rarely restricted to a single technique or approach.

Although we believe that formulae should be provided and the logic of the approach explained as an aid to understanding, we have avoided showing the details of complex calculations —most readers will have access to computers and are unlikely to perform any but the simplest calculations by hand.

We consider that it is particularly important for the reader to be able to interpret output from a computer package. We have therefore chosen, where applicable, to show results using extracts from computer output. In some instances, where we believe individuals may have difficulty with its interpretation, we have included (Appendix

C) and annotated the complete computer output from an analysis of a data set.

There are many statistical packages in common use; to give the reader an indication of how output can vary, we have not restricted the output to a particular package and have, instead, used three well known ones —SAS, SPSS and Stata.

There is extensive cross-referencing throughout the text to help the reader link the various procedures. A basic set of statistical tables is contained in Appendix A. Neave, H.R. (1981) Elemementary Statistical Tables Routledge, and Diem, K. (1970) Documenta Geigy Scientific Tables, 7th Edn, Blackwell Publishing: Oxford, amongst others, provide fuller versions if the reader requires more precise results for hand calculations. The Glossary of terms (Appendix D) provides readily accessible explanations of commonly used terminology.

We know that one of the greatest difficulties facing nonstatisticians is choosing the appropriate technique. We have therefore produced two flow charts which can be used both to aid the decision as to what method to use in a given situation and to locate a particular technique in the book easily. These flow charts are displayed prominently on the inside cover for easy access. The reader may find it helpful to assess his/her progress in selfdirected learning by attempting the interactive exercises on our Website (www.medstatsaag.com). This Website also contains a full

set of references (some of which are linked directly to Medline) to supplement the references quoted in the text and provide useful background information for the examples….