Allow option of using order-sign hook

[cfeltner]

Allow the option of using either the order-select or order-sign hook to trigger calling the CDS Service to determine if the order meets the acceptable use guidelines. Using the order-sign hook would seem to reduce the needed number of calls to the CDS Service since all the order details are complete at this point. With using the order-select hook, the CDS Service would need to be called whenever the order details are changed since a change in the details may change whether the radiology order meets the acceptable use criteria.

[jmandel]

We should clarify that the motivation for using order select is user experience, rather than CDS minimizing CDS Service calls. That said, as currently documented, the order select call allows an EHR to wait until details are available before firing the hook, so it's currently possible to scope down the number of requests. The key reason for emphasizing order select instead of order sign is that we do not want to interrupt the user at all, and especially not late in a process. This is especially true because in most cases the CDS service will probably be responding with a link to guide the user through a selection process. It would be frustrating to go through a selection process mentally and then be asked to go through it again using a tool once one had reached one's own conclusion.

I think this is something that we should reconsider once we have a bit of experience, but I would rather figure out the best hook than provide a list of choices if we can avoid it.

[jmandel]

Also: hey thanks for reading closely and :+1: on submitting PR#1 :-)

[cfeltner]

Thanks. The motivation for using the order-sign hook could also be viewed as user experience. For example, in the scenario where the physician is placing 3 radiology orders for perhaps different areas of the body (head, cervical spine, thoracic spine), with the order-select hook, the CDS Service would be called 3 times and the physician would be given a link to launch the SMART app each time. With the order-sign hook, the CDS Service is called once when all the orders are in and ready to be signed. This would reduce the number of interactions and notifications to the physician. This could also possibly reduce the number of interactions with the SMART App which would allow the physician to complete the process faster.

The selection of the best hook to use is likely highly dependent on the design and flow of the EHR's CPOE system. By allowing either order hook to be used, it would then be up to the EHR to select the hook that offers the best user experience with their CPOE system.

[brettmarquard]

accepted on prior call!