The following example shows how information can be described in different ways. This is an imagined example and does not refer to any real medicine or research.
It shows that both the effectiveness of the treatment and the potential side effects should be considered when making treatment decisions.
A doctor may recommend a new drug to someone who is about to start chemotherapy, as it may help prevent hair loss. Before agreeing to have this medicine, the person may want to know about the side effects, how many people had side effects and whether some people had no side effects.
The doctor tells them that:
In a study of 100 people, the side effects included:
a sore throat.
In the study:
50 people had headaches = 50%
80 people felt tired = 80%
25 people had a sore throat = 25%.
There were some rarer side effects too:
1 person had an allergic reaction = 1%
2 people had very itchy skin = 2%
4 people had a stomach ache = 4%.
Some people had no side effects at all while others had a few different side effects.
The same information can be communicated using a diagram; for example, this can be shown in a bar chart:
Chart showing types of side effects of chemotherapy
View a large version of the chart showing types of side effects of chemotherapy.
The person may also want to know in how many people the drug prevented hair loss. The doctor explains the results of the study:
Of the 100 people who took the new drug, 70 people found the drug slowed down the hair loss or stopped them from losing their hair, although some still needed a wig.
A total of 10 people had no hair loss, 23 had minimal hair loss, 37 had a lot of hair loss and had to get a wig, and 30 had total hair loss. In all, 67 people still needed to get a wig despite having the drug.
The numbers are a lot to take in, and the information may be clearer to see in diagrams.
The pie chart shows how many people had hair loss and whether they needed a wig.
Pie chart showing wig use and hair loss
View a large version of the pie chart showing wig use and hair loss.
The person may also want to know more about the overall impact of the side effects on people’s lives.
The doctor tells them:
Of the 100 people who took the new drug, 23 people had all of the more common side effects and felt so tired it really affected their day-to-day lives.
Of those people who had headaches, most found they were quite mild. Only a few had problems so severe that they had to stop taking the medicine.
The person who had the allergic reaction didn’t have the drug again; neither did the people who had a stomach ache.
This can be shown in a ‘smiley face’ diagram :
Diagram showing frequency of side effects
View a large version of diagram showing frequency of side effects
Having seen these results, one person may decide that they would rather lose their hair than have those side effects. Another person may decide that, as most people felt OK, they’ll try the medicine even though there is still a high chance they may need a wig. There is no right choice.
There are many ways of showing information. Remember that it’s fine to ask for repeated explanations if there’s something you don’t understand.