I am designing a Viz to represent the movement of patients around our hospital's Accident and Emergency (ER to our American friends) department showing the duration period of each room. The implementation has gone pretty well using a Gantt chart, where the arrival date-time dimension is plotted on the x-axis against the room on the y-axis. Nice bars appear proportional in length to the duration in each location, placed so that they all seem to start and end in line with the time on the x-axis and when a patient identifier is dropped onto the colour mark, we can see each patient-stay distinctly.
So far so good.
Unfortunately, if a patient has moved from room A to room B and back to room A again, something unexpected happens within the Gantt chart. First, a single bar stretches from the earliest arrival to the final departure in room A (even though there will be a gap in the middle). In the tool tips, attributes common to both periods in room A are displayed, e.g. patient identifiers. Attributes unique to the period, e.g. the arrival and departure dates, are overwritten with asterisks.
I've read the other posts about this phenomenon on this site. No data blending is taking place. And I've tried using moving values to the detail and using a calculated field featuring the previous_value function.
The return to the room is key: I experimented with the data whereby I gave each patient's room stay an incrementing number. So, my example patient arrived in room "A1" went to "B1" and returned to "A2". Then the tool tips displayed perfectly. If the room is given a unique name each time, the problem disappears. Unfortunately to be usable, I cannot publish that to my users.
So, my question is this: is my mistake in using the Gantt chart to display these data this way? It seemed a very natural fit and works 99% of the time. But it's arguable I'm using the wrong technology and other suggestions are welcome.
I'm afraid I cannot post patient-identifiable data on this site to help you all work through it and pseudonymization could take a while.
Thanks in advance for any advice/suggestions.
And yes, I've only been at this a couple of months, so treat me gently.
Hi Vishal,
Thanks for getting back to me.
Here's where I've got to thus far.
Each coloured block represents a patient's stay in the room listed on the Y-axis. You can trace a patient's progress through the rooms by highlighting an MRN in the highlight thing on the right hand side.
The times of when they stayed are along the bottom (though I appreciate not too easily read at this stage). If you look at the coloured blocks that break across the left border on the rows marked "Initial *** Mid", "Majors HD2" and "Resus 2" these are examples of patients who went to one room, then another room, then back to the first. When I hover my mouse over these, the room-stay-specific values (e.g. the times of arrival to and departure from that room on that occasion) are replace by "*".
Make any sense?
