Part 6: Testing your skill

Chapter 15: Making sense of health advice

This chapter gives several practical examples to allow you to put into practise what you have learnt from the book. Working through these examples will help to reinforce some of the important lessons of the book.

Chapter 16: Is this a useful diagnostic test?

Tests are not 100 per cent accurate. Sometimes they give false-positive results and sometimes they give false-negative results. This chapter gives some of the background for understanding the reliability and limitations of tests.

Chapter 17: Decision thresholds

This is a concept for helping you to decide when it is worth testing for a disease, or deciding whether to treat or not treat without further tests.

Chapter 18: Relative risk, relative and absolute risk reduction, number needed to treat and confidence intervals

These concepts are not as complicated as they might sound, and are explained in a way that is easy to grasp. Understanding the difference between relative and absolute risk is helpful for assessing many health issues. It can also be useful to know the number of people who need to be treated for one person to benefit or to be harmed. Confidence intervals are a statistical term which give an idea of how confident you can be about a study’s results.