- C Charts are used to display counts of things we are trying to avoid happening, (e.g. number of violence incidents, number of falls, number of pressure ulcers) where a fixed sample size exists.
- It is helpful to note at this point that often we have an inconsistent sample or "area of opportunity" for things we are working on. For example, a hospital working on reducing the number of falls on their wards, will have different number of patients from week to week so their sample size will vary considerably. For a situation similar to this we recommend using a Percentage Chart (P Chart) or Rate Chart (U Chart).
Typical Examples would be:
- Number of falls
- Number of violent incidents
- Number of pressure sores
C Chart Example
Here we will show you what data is required when creating a C-Chart and how this is reflected in the chart itself.
So lets say the 'Aim' of the project was to:
Reduce the number of patient falls by 60% in 12 mths on Ward B.
and the measure was:
Number of patient falls on Ward B.
You would need to capture the following data:
| Time Period |
Dates when the value was recorded
(Daily, Weekly, Monthly)
|
| Count |
The number of people that hit that criteria (Patient falls each day)
Sample size doesn't need recording as it should be the same each day
|
Data Capture Example:
Number of patient falls on Ward B each day
C Control Chart Example:
Number of patient falls on Ward B each day
If you want to learn more about SPC then take a look at our