Immunization Information Systems (IIS) and data tracking during Pandemics

A small group of people are currently working in HL7 (particularly in Public Health and Emergency Response - PHER) to try to create a standardized way to track certain characteristics of patients that may be in a higher risk and may be a priority for certain types of immunizations. Once example of this would be during the last Pandemic response for H1N1.

The problem is actually quite a bit more challenging because in order for the IIS to track this information, it needs to receive it from the EHR system (EHRS), and more importantly, the EHRS should capture this information. However, it is difficult to collect and transmit all data that might ever be important for classifying patients into these priority categories, mainly because it is impossible to predict all the data we will need for emergencies scenarios we've yet to uncover.

The approach that HL7 and PHER are taking seems like a good balance - collect the information that has been useful in the past, and then allow for addition of more information later. The proposal is to use OBX segments (OBX-3 and OBX-5) where OBX-3 would always be the LOINC code 59785-6 - Immunization Indication and the OBX-5 value would be the appropriate Snomed code for clinical data elements such as pregnancy, immune compromised, abnormal liver function, abnormal renal function, etc. This seems like an approach that would work with the caveat that the EHRS would have to map the particular Snomed codes that the CDC categorizes with what the providers enter into the system.

The approach for this problem seems to be the most elegant I've seen so far. The challenge is that of activating this during a pandemic response, and making sure that the providers are entering the appropriate information all through, so that during the response, we have the correctly identifiable data to put patients into the correct priority lists for particular immunizations.

One could also argue that a mapping or crosswalk of the Snomed codes might be a possibility, and it is - as long as we are willing to do one of two things:
1. Place the burden on the EHRS to execute this mapping
2. Send large amounts of data from the EHRS to the IIS and have the IIS execute the mapping

Food for thought...