More about stock control data

In the previous blog, we described what the Secondary Care Medicines Dataset (SCMD) is and where it comes from. We briefly explained that the SCMD is collated from hospital pharmacy stock control systems, not from individual patient prescriptions. In this blog we will explain what impact this has on the way the data is made available.

What is stock control data?

Stock control data is information collected from hospital pharmacy systems that is used to track and manage medicines use within hospitals. These systems support management of inventory levels, monitoring of medication usage and cost tracking.

The data within the SCMD describes medication distribution within hospitals, such as issuing of medicines to wards or clinical areas, rather than actual patient-level prescribing. Not all of the stock that is issued within hospitals eventually ends up being used. In some hospitals, when this is the case and where their stock control system supports it, historical stock issues can be updated. This is known as Backtracking.

Around 45% of the data sources for the SCMD are subject to backtracking. The extent of backtracking varies across hospitals and by month but is at its greatest within 3 months of the initial issuing.

Provisional vs finalised data

Rather than wait until all backtracking of data has been completed, new monthly data in the SCMD is initially made available as provisional data. The data within these files is subject to change.

Finalised data are made available following a 3-month period after the end of each financial year, which will have accounted for the majority of backtracking. Though, at the time of writing, finalised data is only available up to March 2022 (you can see the status of the data each month on our Submission History page, which we’ve previously outlined).

More information on how often the data is updated is provided on the dataset description and in the supplementary dataset guidance.

How much does the data change between provisional and finalised data?

Although we know that ~45% of the data sources for the SCMD are subject to backtracking, we can’t estimate the extent of backtracking until we can directly compare a provisional release with a finalised release. Currently, finalised versions of the data overwrite the provisional release, so we haven’t been able to make this comparison, but positively, the NHSBSA have announced a new version of the SCMD, which publishes provisional and finalised versions separately to make this easier. Hopefully, this will also fill in the gap of finalised versions of data for 2022-23 and 2023-24, which we’d expect to be published already according to publishing timeline in the dataset description. We’ll report back once this new version is available!

How does this impact the use of the data?

Until we understand the extent to backtracking, any provisional data will have to be treated as such and care should be taken if drawing any conclusions from data in this period. When presenting provisional data on our platform, we will need to make sure users are aware of the difference between provisional and finalised data.

This blog has discussed what we know so far about the SCMD and how it is updated. If you know more about how this works, please get in touch.