Dealing with multiple person source values for patients

Implementers
1

Hi,

We’re currently OMOPing NHS data. There are instances where an individual patient’s NHS number might change (several times). We have a table of NHS number updates. What is the most OMOP-aligned way of dealing with this? We’d like to be able to retrieve records from the original datasets after looking at an OMOP entry.

Approaches we’re considering:

  1. Having it exclusively in the ETL. Passing each dataset through the NHS number updates table and temporarily replacing old NHS numbers with new ones, such that the OMOPed data only refers to the latest iteration of NHS numbers and is unaware of older ones. This seems most likely to be OMOP aligned but it feels like it misses out on potentially important context, and makes ETL a tiny bit clunkier. Additionally, makes it harder to retrieve original records (you would need to remember to check the NHS number updates table every time).

  2. Recording NHS number changes in Observations. This doesn’t ‘change’ any of the OMOP structure, but feels like it would be really clunky to use.

  3. A separate table with each person_id, NHS number pair. This feels the least OMOP-aligned (adding a new table), but feels the most convenient.

  4. Dropping records with old NHS numbers. This feels quite OMOP-aligned, but we’d rather not do this.

2

Hi @Areeb:

It’s 3. Or even better, just add another field “old_person_source_value” or “nhs-id” or “field_only_for_areeb”.

Reason is: The OMOP CDM supports standardized and systematic research, potentialy in a network of institutions. Which means all fields have a standard meaning that is understandable outside your organization. Research only meaningful to the NHS is not supported, but also not prevented. Even the “person_source_ value” is for pure convenience, no standard tool or script will use it.

So, feel free to add fields to the database, it will not hurt anything.

1 Like
3

Thank you so much! We had the strongest inclination for 3, but wanted to check if there was any reason not to do it that we hadn’t considered, or just a better way of dealing with this that we hadn’t thought of. We’ll likely make it a table since it’s possible for the NHS number to change multiple times.