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 Link to this message Tanya Garber  posted on Thursday, February 17, 2005 - 03:45 pm Edit Post Delete Post Print Post
I wish to challenge the advocated notion of bi-directional interfaces between a HIS/PAS and a RIS system on the grounds of data quality. I was recently asked whether RIS should have a true bi-directional link to PAS.

The only bi-directional interfaces that appear to make sense are between the modality and RIS, and RIS and PACS.

A RIS/Modality interface is crucial and must be bidirectional. This offers the means for the modality to accept information from the RIS for patient demographics etc and allows the modality the path to send information back to the RIS for validation. The information provided would consist of exam start and completion along with total images and where the images are located. Exam location is critical to retrieval speed. When an exam is requested from a workstation other than the original destination, why retrieve from the archive when retrieving from a local station is faster, a RIS is built to handle this logic function with great speed and resource efficiency.

The bi-directional interface between the RIS and the modality facilitates scheduling and image retrieval. It eliminates common spelling errors that can occur with printed patient requests. This feature alone can prevent costly time of editing patient files because the data is validated without any manual typing. Without a validation feature exams performed on the same patient have a high risk of winding up in separate files..

The functionality that may be desired is not really a bi-directional link between PAS and RIS but a strong link in the PAS-RIS interface is to reduce data entry time and provide a single source of access to patient and exam data. This in my opinion does not need to be bi-directional but rather a reliable one.

A nearby site has effectively dealt poor PAS-RIS or registration issues by installing a PAS terminal (for selected users) within the radiology department. This enables staff to determine if and when the patient has been registered or to register them at the source, ie PAS, not RIS.

Data quality issues prohibit enabling the bi-directional mechanism between PAS and RIS. A Bi-directional interface between feeder systems and PAS may be useful down the track especially when we don't have missing NHS numbers to begin with.

For the time being, the only way it would be ok would be to protect key fields to ensure that PAS data is not corrupted. If too many feeder systems have the ability to change the "master" index on PAS, there are huge data quality issues.
 Link to this message Ivan Brown  posted on Thursday, February 17, 2005 - 05:06 pm Edit Post Delete Post Print Post
I would agree that the need is NOT for the ability to alter the PMI data which would be a disaster but there is a need for bi-directionality to PAS where the PAS (with or without an Interface Engine) acts as the integrator for hospital-wide systems. Unless the insititution has trust wide links for Order comms and results/progress into the RIS then the PAS functions as a single portal for this type of enquiry. PMI should not be confused with PAS.
 Link to this message Alex Anderson  posted on Thursday, February 17, 2005 - 10:06 pm Edit Post Delete Post Print Post
I agree with everything you say and accept that a RIS / Pas link is essential at least as uni-directional. I held similar views on bi-directional Pas links until it was implemented at one of our sites. IT has proved to work with few issues and no data integrity or quality issues.

Since imaging and other departments often see patients many times more than admissions the bi-directional interface has enhanced the PAS data with relevant and up-to-date information particularly when it comes to address and phone numbers. This is helpful for recalls etc. which may occur months or years out form the admission. A good implementation allows for monitoring and auditing of changes and allows the interface to be monitored for unacceptable changes.
 Link to this message Padhraic Conneally  posted on Monday, February 21, 2005 - 12:11 pm Edit Post Delete Post Print Post
bidirectional real time link with master database is essential if it to be of any use longterm.
Look at your hospital pt flows you will probaly find that radiology has more face to face contacts in total with your local comunity than any other hospital service and is an ideal point provided radiology reception staff are appropriately trained to update the master database.
 Link to this message Tom Henderson  posted on Wednesday, February 23, 2005 - 07:51 pm Edit Post Delete Post Print Post
Having had a uni-directional His to Ris for 5 years for Pacs and bi directional for Pacs to Ris we are now moving to a Bi directional for Ris/His
Padhraics comments are quite correct; however Tanya’s comments re data integrity are extremely important. Systems which have not been linked and therefore updated manually will have many pts incorrectly entered under the wrong numbers etc it is essential that any move to bi directional merges updates, has all the catches in place to ensure the system doesn’t start updating and merging the wrong pts.
Do the systems remember and index on previously Known numbers or does an update remove them from the data base etc.

We are moving to bi directional for the reasons given by Padhraic for demographics but we will also feed lots of other radiology data to our clinical portal not presently passed back and receive much needed data for RIS developments not yet available...I.E Present pt location / future clinic appointments etc.
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