Epidemiology & Biostatistics: The Exam Companion

From First Principles to SMLE & Board-Level Questions

Understand the concepts. Recognise the patterns. Solve the problems. Interpret the evidence.

Epidemiology and biostatistics are fundamental to medicine, public health and evidence-based practice. They help us understand patterns of disease, evaluate interventions, interpret research findings and make better-informed decisions.

Yet these subjects are often challenging for students. Not because the underlying ideas are necessarily inaccessible, but because learning can become a matter of memorising formulas, definitions and statistical tests without developing a clear understanding of what they mean or when they should be used.

Epidemiology & Biostatistics: The Exam Companion was developed around a different principle: understanding should come before memorisation, and interpretation should follow calculation.

The book builds knowledge from first principles, connecting epidemiological concepts and statistical methods to the questions they are designed to answer. It aims to help readers understand not only how to obtain an answer, but also why a particular method is appropriate, what the result means and what conclusions the evidence supports.

Who is this book for?

The book is designed for readers who need a clear, structured and practical understanding of epidemiology and biostatistics, including:

• Medical students preparing for examinations.

• Candidates preparing for the Saudi Medical Licensing Examination (SMLE) and similar examinations.

• Preventive medicine residents and candidates preparing for postgraduate and board examinations.

• Public health and other health sciences students.

• Healthcare professionals seeking to strengthen their understanding of research methods and statistical reasoning.

It can be used as a structured introduction, a revision companion or a reference when working through epidemiological and statistical problems.

What will you learn?

The book takes readers from foundational principles towards more advanced methods and their applications.

Its coverage includes:

• Understanding and describing data: data types, descriptive statistics, distributions and variation.

• Probability and statistical inference: the foundations of statistical reasoning, hypothesis testing and confidence intervals.

• Choosing statistical tests: matching research questions and data characteristics to appropriate analytical methods.

• Regression and advanced statistical methods: understanding relationships between variables and interpreting model results.

• Measuring disease and association: epidemiological measures used to describe disease frequency and investigate relationships.

• Study design: understanding how different research designs address different questions.

• Bias, confounding and causation: evaluating validity and distinguishing association from causal inference.

• Diagnosis and screening: interpreting measures of diagnostic accuracy.

• Survival analysis: understanding time-to-event outcomes.

• Evidence-based medicine and critical appraisal: evaluating the quality, meaning and limitations of research findings.

• Systematic reviews and meta-analysis: understanding the synthesis and interpretation of evidence across studies.

From concepts to application

Understanding develops through practice. The book therefore combines explanations with resources intended to help readers apply what they learn.

Graph Lab develops the ability to read and interpret figures commonly encountered in epidemiology, biostatistics and research publications.

Calculation Lab provides opportunities to practise numerical problems and apply statistical formulas.

Integrated cases bring together concepts across different areas of the subject, encouraging readers to connect methods rather than treat each topic in isolation.

Decision aids, exam-focused comparisons and a glossary support revision, clarify commonly confused concepts and provide useful reference points during study.

Together, these resources are intended to help readers move beyond isolated facts towards a more connected understanding of epidemiology and biostatistics.

The principle behind the book

A formula is useful only when you understand the problem it addresses. A statistical test is meaningful only when you understand why it is appropriate and how to interpret its result. And an association, however strong, does not automatically establish causation.

These distinctions matter in examinations, but they matter just as much in clinical practice, public health and research.

The aim of this book is therefore not simply to help readers recall information. It is to develop the reasoning needed to select methods, interpret findings, recognise limitations and reach defensible conclusions.

Whether you are learning epidemiology and biostatistics for the first time, preparing for an important examination or strengthening your ability to interpret research, this book offers a structured path from foundational concepts to more demanding applications.

Learn the reasoning behind the answer—not just the answer itself.

About the author

Dr Ghaiath Hussein is an Assistant Professor of Medical Ethics and Law at Trinity College Dublin, Ireland. His academic work spans medical education, research ethics and public health, with an interest in making complex concepts accessible and relevant to healthcare practice.

Get your copy

Choose your preferred format and begin developing a clearer, more practical understanding of epidemiology and biostatistics.

This is an independent educational resource. Its examination-style questions are original practice materials, not official examination questions. The book is not affiliated with or endorsed by any licensing or examination authority.