Data
Scientists use graphical and statisticsCollection and interpretation of data. methods to analyse patterns of data related to disease.
Drawing graphs
Data are often displayed in a graph. Graphs might display trends that are not as clear when just looking at data in a table.
Bar charts show data collected for separate groups. The height of the bar is proportional to the measured number or frequencyThe total number of times an event occurs..
This table of data and bar chart show the number of deaths that could be avoided in England and Wales in 2023 from different causes.
| Cause of death | Number of deaths that could be avoided, rate per 100,000 of population |
| Cancer | 74.9 |
| Cardiovascular disease | 66.1 |
| Alcohol and drug-related | 27.3 |
| Infectious diseases | 4.2 |
| Injury | 18.3 |
| Respiratory disease | 30.1 |
| Other | 17 |
| Cause of death | Cancer |
|---|---|
| Number of deaths that could be avoided, rate per 100,000 of population | 74.9 |
| Cause of death | Cardiovascular disease |
|---|---|
| Number of deaths that could be avoided, rate per 100,000 of population | 66.1 |
| Cause of death | Alcohol and drug-related |
|---|---|
| Number of deaths that could be avoided, rate per 100,000 of population | 27.3 |
| Cause of death | Infectious diseases |
|---|---|
| Number of deaths that could be avoided, rate per 100,000 of population | 4.2 |
| Cause of death | Injury |
|---|---|
| Number of deaths that could be avoided, rate per 100,000 of population | 18.3 |
| Cause of death | Respiratory disease |
|---|---|
| Number of deaths that could be avoided, rate per 100,000 of population | 30.1 |
| Cause of death | Other |
|---|---|
| Number of deaths that could be avoided, rate per 100,000 of population | 17 |
Question
Use the information in the bar chart to find out the number of deaths that could be avoided resulting from causes other than those in the table.
Seventeen per 100 000 of population.
This stacked bar chartA bar chart in which the bars are divided up into catergories. shows proportions of cases of cancer in the USA connected with the Human papilloma virus (HPV), and those where no connection has been established.
Note that bar charts are sometimes displayed horizontally.
Histograms
histogram A graphical representation of the distribution of numerical data. look similar to bar charts, but show how frequently data occurs within certain ranges.
The independent variableThe variable that is changed, to investigate its effect on the dependent variable in an experiment. is therefore continuous and is divided into sub-sections or classes.
This histogram shows data from a Scottish study of the proportion of people of different ages with depression who consult their doctor. The independent variable here is age, but the histogram shows different groups within the variable of range allowing the data to be visually comparable.