Aviva Petrie is Honorary Associate Professor, Biostatistics Unit, UCL Eastman Dental Institute, London, UK.Caroline Sabin is Professor of Medical Statistics and Epidemiology, Department of Primary Care and Population Sciences, Royal Free and University College Medical School, London, UK.

• Preface ixPart 1 Handling data 11 Types of data 22 Data entry 43 Error checking and outliers 64 Displaying data diagrammatically 85 Describing data: the ‘average’ 106 Describing data: the ‘spread’ 127 Theoretical distributions: the Normal distribution 148 Theoretical distributions: other distributions 169 Transformations 18Part 2 Sampling and estimation 2110 Sampling and sampling distributions 2211 Confidence intervals 24Part 3 Study design 2712 Study design I 2813 Study design II 3114 Clinical trials 3415 Cohort studies 3716 Case–control studies 40Part 4 Hypothesis testing 4317 Hypothesis testing 4418 Errors in hypothesis testing 47Part 5 Basic techniques for analysing data 51Numerical data19 Numerical data: a single group 5220 Numerical data: two related groups 5421 Numerical data: two unrelated groups 5722 Numerical data: more than two groups 60Categorical data23 Categorical data: a single proportion 6324 Categorical data: two proportions 6625 Categorical data: more than two categories 69Regression and correlation26 Correlation 7227 The theory of linear regression 7528 Performing a linear regression analysis 7729 Multiple linear regression 8130 Binary outcomes and logistic regression 8531 Rates and Poisson regression 8932 Generalized linear models 9333 Explanatory variables in statistical models 96Important considerations34 Bias and confounding 10035 Checking assumptions 10436 Sample size calculations 10737 Presenting results 111Part 6 Additional chapters 11538 Diagnostic tools 11639 Assessing agreement 11940 Evidence-based medicine 12441 Methods for clustered data 12742 Regression methods for clustered data 13043 Systematic reviews and meta-analysis 13444 Survival analysis 13845 Bayesian methods 14246 Developing prognostic scores 144Appendices 147A Statistical tables 148B Altman’s nomogram for sample size calculations (Chapter 36) 155C Typical computer output 156D Checklists and trial profile from the EQUATOR network and critical appraisal templates 169E Glossary of terms 178F Chapter numbers with relevant multiple-choice questions and structured questions from Medical Statistics at a Glance Workbook 188Index 190