Processing Patient Data within an NHS hospital – a quick guide

patientThe processing of patient data within any hospital or NHS Trust, is the bread and butter of the information service.   Detailing the patients that have moved into and out of a hospital, had procedures carried out, or have been seen by a clinician is the most common forms of data to be processed by a hospital.

The following is the most common processes, considerations or terms used when processing and dealing with patient data.

Patient data is deemed to be highly sensitive.  Therefore any form of electronic communication outside of a hospital requires that patient data is removed or replaced (i.e, all patients renamed to “Mickey Mouse”).  Generally, patient internal numbers (MRN) and nhs numbers are not restricted, but the other demographics including name (first, middle and last), address, sex, date of birth, martial status, contact numbers and next of kin information is also deemed sensitive and needs to be protected.

Data Feeds
Generally, patient data is provided between systems in one of two forms.  Electronic patient records are provided as ADT (Admission, Transfer and Discharge) HL7 messages and contain the patient information.  For systems combined to the UK NHS national program for IT (Cfh/NPfIT) systems, ADT messages are no longer provided, but instead come through CDS/IM200 extractions.   This later form of message are more complex to process as there is no trigger point for the generation of the data.  That said, it is possible for local non-LSP systems (EPRs, patient indexes or PAS) to provide ADTs to downstream systems.

For systems connected to the UK NHS spine, all patient information is held nationally by the PDS – The Personal Demographic System – part of the NHS data spine provided and supported by BT.  For systems to connect to the spine and the PDS, systems have to be sponsored and verified by one of the UK local service providers (BT or CSC).  Once connected, the PDS is viewed as the master demographic source.  Therefore when a patient record is accessed, the PDS should be queried and any local patient details updated with those held on the spine.   When patients update their details (such as the address) linked systems can push demographic updates back to the PDS.

By far, the most complex area of patient processing is patient merges.  Merges happen when a patient is allocated a temporary internal PAS reference, and later on is found to be on the PAS under a different number.  A merge is then carried out on the PAS (Patient Administration System) and a merge message sent out to all other systems via an ADT (028) merge message.  Both the PAS and other connected systems then have to merge the patient activities into the correct patient record.   It should be noted that patient merges are not hard merges (the data is not just renumbered) as it is possible merges happen my mistake, so an unmerge facility should also be supplied.