1. Which Chart Is Right? By Farrokh Alemi Ph.D.
These slides were organized by Farrokh Alemi.

2. Types of Charts Which is Right?
This lecture should help the user select the appropriate type of chart. We assume that the user has a basic understanding of each of the different types of charts.

3. XmR X-bar Tukey Time-in-between P-chart
There are many different types of control charts possible.

4. Risk-adjusted Time-in-between Risk-adjusted P-chart
Risk-adjusted XmR
Risk-adjusted X-bar
Risk-adjusted Tukey
Risk-adjusted Time-in-between
Risk-adjusted P-chart
Furthermore, it is possible to analyze each chart type using risk adjustment or without risk adjustment.

5. Average age of a specific patient population Turn around time
Continuous Measures
Length of stay
Average length of stay
Average age of a specific patient population
Turn around time
Staff salaries
Severity of medication errors
Individual patient’s weights
Individual patient’s blood sugar
Patient satisfaction average scores
Infectious waste poundage generated
Electrical usage
Wait times
Accounts receivable balances
Time in restraints
Time before hanging up the phone
SF – 36 scores
Which chart is right depends on what type of data you have. Here are a list of continuous variables. These variables are measured using an interval scale, where division and multiplication of the numbers make sense. Cost of care and wait time are two examples of continuous measures. These measures are typically analyzed using X-bar chart. Tukey chart analyzes medians of these measures.

6. Rates & discrete Measures
Employee accidents
Patient falls
Nosocomial infection rates
Percent of patients in restraints
Medication error rate
Adverse event rate
C-Section rates
Dietary tray errors
Delinquent medical records
Patients who kept their resolutions
Percent of patients with insurance
Percent of patients who rated the facility as excellent
Telephone abandonment rates
Pressure ulcer rates
Employee injuries rates
Percent with appropriate documentation
Discrete events require a different type of control chart. Some examples of discrete events are patient falls or medication errors. Typically the rate of these events are analyzed using P-chart or time between control charts.

7. If continuous variable
Which Chart is Right?
If continuous variable
If one data point per time period
If outliers likely: Tukey chart
If outliers not likely: XmR chart
If multiple data points per time period: Xbar chart
If discrete event
If event is rare: Time-in-between chart
If event is not rare: P-chart
If we are dealing with a continuous measure, and if we have one data point, use Tukey chart if there are outliers.

8. If continuous variable
Which Chart is Right?
If continuous variable
If one data point per time period
If outliers likely: Tukey chart
If outliers not likely: XmR chart
If multiple data points per time period: Xbar chart
If discrete event
If event is rare: Time-in-between chart
If event is not rare: P-chart
If we are dealing with a continuous measure, and if we have one data point, use XmR chart if there are no concerns for outliers.

9. If continuous variable
Which Chart is Right?
If continuous variable
If one data point per time period
If outliers likely: Tukey chart
If outliers not likely: XmR chart
If multiple data points per time period: Xbar chart
If discrete event
If event is rare: Time-in-between chart
If event is not rare: P-chart
If we are dealing with a continuous measure, and if we have multiple data points per time period, use X-bar chart.

10. If continuous variable
Which Chart is Right?
If continuous variable
If one data point per time period
If outliers likely: Tukey chart
If outliers not likely: XmR chart
If multiple data points per time period: Xbar chart
If discrete event
If event is rare: Time-in-between chart
If event is not rare: P-chart
If the measure is discrete and the event is rare, then use time in between charts.

11. If continuous variable
Which Chart is Right?
If continuous variable
If one data point per time period
If outliers likely: Tukey chart
If outliers not likely: XmR chart
If multiple data points per time period: Xbar chart
If discrete event
If event is rare: Time-in-between chart
If event is not rare: P-chart
If the measure is discrete and the event is not rare, then use p-charts.

12. Case Mix Change Risk Adjust
Which Chart is Right?
Case Mix Change
Risk Adjust
When case mix changes over time, use risk adjusted control charts. Instead of comparing to historical patterns, new observations are compared to expectations derived typically from patient’s conditions.

13. Select the Right Chart for Your Data
Think it through, select the right chart for the specific data you are analyzing.