Points that are both improvement and deterioration

[alexmcqueen]

It is possible points can be both part of rules that are of improvement and of deterioration. For example a point may be the last point in a run of points trending down but be the first point in a run of points trending up. A point could also be an astronomical point for concern and then be the first point in a run of points trending up for improvement.

Currently a point will be indicated by one or the other. However it appears in the current implementation how this is determined is based upon if the improvement diection is set to INCREASE or DECREASE. This means you will get a different outcome based on the direction of travel.

Below is an example of this. It shows the same points of data; the left where the improvement direction = decrease and the right where improvement direction = increase. For each it shows all rules, and then rules for improvement only and deterioration only. You can see the cluster of three points that contribute to improvement and deterioration highlighted in the red box. What you see has changed based upon the direct of travel.

For better consistency and improved functionality it would be better if one or more of the following could be implemented:

• Either improvement or deterioration always trumps the other. From a NHS Making Data Count perspectice my understanding was originally improvement trumped deterioration / concern, although this could have changed.
• You have the option to choose which ones trumps the other
• You have the option to use a different colour or have the point coloured half and half, either with a direct half cut or two circles on top off each other like the below:

[alexmcqueen]

This was tested using the i chart type.

[andrjohns]

That's a great question! I've raised it with the NHSRplotthedots/MDC team for a definitive answer: nhs-r-community/NHSRplotthedots#200

[alexmcqueen]

@andrjohns did you get anywhere with NHSRplotthedots/MDC team? If not I might see if I can follow it up as well.

[andrjohns]

@andrjohns did you get anywhere with NHSRplotthedots/MDC team? If not I might see if I can follow it up as well.

Unfortunately nothing yet, there hasn't been any response to the issue I opened above

[alexmcqueen]

Hey @andrjohns. Was able to get some information on the NHS-R implementation. Believe that points are evaluated in this order:

1. Above UCL / Below LCL (astronomical point)
2. 7 Point Trend (Increasing) / 7 Point Trend (Decreasing)
3. 2 in 3 Above CL / 2 in 3 Below CL
4. 7 Points Above CL / 7 Points Below
5. Common Cause

In the case where a point is both increasing or decreasing then it will be considered part of the right hand trend. So Imagine we have 13 points, the first 7 are decreasing, then the next 6 are increasing. So we have x1 > x2 > x3 > x4 > x5 > x6 > x7 < x8 < x9 < x10 < x11 < x12 < x13. Point x7 here is both decreasing and increasing. x1-x6 are flagged as a decreasing trend of 7 (with only 6 points in that group) and x7-x13 as increasing.

[alexmcqueen]

Further from this It could be useful to have options in the configuration for methods of resolving. For example:

1. Use rule order (as above)
2. Improvement beats deterioration
3. Deterioration beats imporvement
4. Show as something else (different colour, split colour etc) to signifiy both imporvement and deterioration.

[alexmcqueen]

@andrjohns. Update after meeting on 17/04/2024. Am going to speak directly to MDC director about this.

[andrjohns]

@andrjohns. Update after meeting on 17/04/2024. Am going to speak directly to MDC director about this.

Brilliant, thanks for following this up! Once we have an 'official' word, I'll update the default handling and add a settings menu for tweaking it under the 'Outlier Highlighting' group