I Chart

I charts are used for variable (continuous) data i.e. time, money, height/weight, temperature, workload/throughput/efficiency. It can also be used to record measures for each observed unit (e.g. individual weight per patient seen in a service). An I chart is not suitable for things you count (rather than measure); e.g. number of falls, incidents of violence, pressure ulcers.

Typical instances in healthcare would be:

• Waiting times (e.g. Time taken between referral to first assessment)
• Money (e.g. cost of successive admissions)
• Average Weight
• Blood Pressure

I Chart Example

Here we will show you what data is required when creating an I Chart and how this is reflected in the Chart itself.

So lets say the 'Aim' of the project was to reduce the proportion of patients with pressure sores by 50% in six months, and the measure was the average length of hospital stay.

You would need to capture the following data:

Data Capture Example:

Average length of hospital stay

I Control Chart Example:

Average length of hospital stay

If you want to learn more about SPC then take a look at our 'Everything you need to know about Statistical Process Control (SPC)' page.