Understanding the NHSBSA Prescription Cost Analysis (PCA) Monthly Data

Hospital and community medicines data often gets talked about as if it measures “what was prescribed” or “what was used”. In reality, most datasets sit at a specific point in the medicines pathway—written, dispensed, administered, issued, supplied—and that point matters.

The Prescription Cost Analysis (PCA) Monthly Administrative Data published on the NHSBSA Open Data Portal is a dispensing view of prescribing: it summarises prescription items that were dispensed in the community in England and submitted to NHSBSA for reimbursement, grouped so you can analyse volume and cost from national level down to local geography and BNF hierarchy. Open Data Portal+1

In this post, we’ll walk through what the dataset contains, why it’s useful, and the key caveats you need to keep in mind when interpreting results.

What is the PCA Monthly dataset?

The PCA Monthly dataset shows the total volume and cost for drugs, dressings, appliances, and medical devices dispensed in the community in England (and submitted for reimbursement) each month. It is designed so you can analyse spend and activity for:

• a specific product (for example, a single BNF presentation), or
• a broader therapeutic grouping (for example, a BNF chapter like Cardiovascular System). Open Data Portal+1

Importantly, this is not a dataset of what clinicians wrote on prescriptions in primary care systems. It is a dataset of what was processed for reimbursement after dispensing.

That difference matters when you write about findings. With PCA, wording like:

• “More items were dispensed in winter months…”
• “NIC increased for a specific presentation…”

is more accurate than “more was prescribed”, because PCA is focused on dispensing and reimbursement rather than prescribing intent. NHS BSA Open Data+1

Where does the data come from?

PCA data originates from the operational process used to reimburse and remunerate dispensing contractors.

Dispensing happens across multiple community settings (e.g., community pharmacies, appliance contractors, dispensing doctors and personally administered items). Prescriptions are then submitted to NHSBSA either as:

• Electronic Prescription Service (EPS) messages, or
• paper forms, which are scanned and processed (including intelligent character recognition). NHS BSA Open Data

Once prescriptions have been processed for reimbursement, NHSBSA extracts and enriches the data (including drug and organisational classifications) into its data warehouse, and publishes PCA as part of its wider prescription data outputs. NHS BSA Open Data+1

How quickly is it published?

The monthly PCA dataset is published retrospectively with a two-month delay (for example, January data is published in March). Open Data Portal

That lag is normal for reimbursement-based datasets: it allows time for submission, processing, validation and downstream enrichment.

Geography and coverage: what’s included (and what isn’t)

Coverage

The dataset is limited to items dispensed in the community in England, regardless of where they were prescribed (e.g., items prescribed in Scotland/Wales/NI but dispensed in England will appear because the dispensing occurred in England). Open Data Portal+1

Exclusions

The dataset excludes, for example:

• items not dispensed, disallowed, or returned for clarification
• prescriptions prescribed and dispensed in prisons, hospital-only dispensing, and private prescriptions
• items prescribed but not presented for dispensing, or not submitted by the dispenser. Open Data Portal+1

How much data is there?

The Open Data Portal version of the PCA Monthly dataset is available from January 2021 onwards, released as one resource per month (CSV/ZIP, plus an API view). Open Data Portal+1

Because each month contains rows across multiple geographies and BNF groupings, PCA quickly becomes a “big-but-manageable” dataset: it is large enough to support meaningful national and local analyses, but structured enough to query efficiently once you understand its keys.

What data does the PCA contain?

Below is a simple model showing how a typical PCA row ties together geography, classification, and measures.

Download the image for your blog: pca_monthly_data_model.png

At a high level, each row in the monthly file is a summary for a specific month + geography + product classification, with measures for volume and NIC.

The dataset includes the following groups of fields (column names are from the Open Data Portal data dictionary). Open Data Portal+1

1) Time

• YEAR_MONTH: Month in YYYYMM format (e.g., 202510). Open Data Portal

2) Geography (dispensing-side)

• REGION_NAME / REGION_CODE: NHS England Region. Open Data Portal
• ICB_NAME / ICB_CODE: Integrated Care Board of the dispensing organisation. Open Data Portal+1

This is one of the key conceptual points: PCA is a dispensing view. When you aggregate by ICB, you are describing dispensing geography, not necessarily prescribing origin. NHS BSA Open Data

3) Dispenser type

• DISPENSER_ACCOUNT_TYPE: categorises the type of English dispensing contractor. Open Data Portal

4) Product identity (BNF presentation level)

• BNF_PRESENTATION_CODE: the BNF presentation code (e.g., 0501013B0AAABAB). Open Data Portal
• BNF_PRESENTATION_NAME: presentation name (e.g., “Amoxicillin 500mg capsules”). Open Data Portal

This is the “anchor” you’ll often join to other datasets (BNF mappings, drug dictionaries, or analysis tooling).

5) Clinical/pack linking fields

• SNOMED_CODE: SNOMED identifier for the medicinal product (VMP/AMP level). Open Data Portal+1
• SUPPLIER_NAME: manufacturer/supplier/wholesaler (where applicable). Open Data Portal
• UNIT_OF_MEASURE: unit used to measure quantity (e.g., tablet). Open Data Portal
• GENERIC_BNF_EQUIVALENT_CODE / GENERIC_BNF_EQUIVALENT_NAME: generic equivalent linkage. Open Data Portal

These fields are extremely useful when you want to analyse:

• branded vs generic patterns,
• supplier differences,
• and the same “clinical thing” represented across multiple pack/supplier variants. NHS BSA Open Data+1

6) BNF hierarchy (therapeutic classification)

PCA includes both codes and names for multiple BNF levels:

• BNF_CHEMICAL_SUBSTANCE_CODE / BNF_CHEMICAL_SUBSTANCE Open Data Portal
• BNF_PARAGRAPH_CODE / BNF_PARAGRAPH Open Data Portal
• BNF_SECTION_CODE / BNF_SECTION Open Data Portal
• BNF_CHAPTER_CODE / BNF_CHAPTER Open Data Portal+1

This is what makes PCA powerful: you can analyse a single presentation or roll up to chemical substance, paragraph, section or chapter without rebuilding the hierarchy yourself. Open Data Portal+1

7) Preparation class (generic vs proprietary vs devices)

• PREP_CLASS: the preparation class assigned/maintained by NHSBSA. Open Data Portal+1
• PRESCRIBED_PREP_CLASS: preparation class of the prescribed presentation (helpful for identifying generic prescribing). Open Data Portal

In the PCA methodology, preparation classes are used to distinguish generic/proprietary and appliances/medical devices. NHS BSA Open Data

8) Measures (the “numbers” you analyse)

• ITEMS: count of times a product appears on a prescription form. Open Data Portal+1
• TOTAL_QUANTITY: total quantity prescribed, calculated using quantity × items. Open Data Portal
• NIC: Net Ingredient Cost in GBP (based on the basic price in the Drug Tariff framework). Open Data Portal+1
• PHARMACY_ADVANCED_SERVICE: flag for items supplied via an advanced service (e.g., Pharmacy First Clinical Pathways). Open Data Portal+1

What NIC means (and what it does not)

NIC is one of the most commonly misunderstood fields.

NIC is useful for consistent comparisons of ingredient cost across products and time. But it is not a complete “cost to the NHS” figure, because it does not include all elements of reimbursement and remuneration (e.g., contractor payments, discounts, patient charges, and other adjustments). NHS BSA Open Data+1

So, NIC is excellent for:

• identifying what drives spend,
• comparing relative trends,
• tracking uptake of medicines and devices,

…but it should not be presented as a final accounting measure of NHS expenditure. NHS BSA Open Data

A note on monthly vs annual PCA (and why totals may not match)

NHSBSA publishes PCA in two main ways:

• an annual accredited official statistic publication, and
• a monthly administrative management information dataset (this Open Data Portal dataset). NHSBSA+1

The monthly dataset mirrors the annual methodology, but it is explicitly not an official statistic. Open Data Portal+1

There are also known structural differences:

• the geographical structure used in the monthly data reflects the end of each month, which can cause rare differences compared to annual totals aggregated from monthly files (especially where organisational mappings change). NHSBSA
• classification can be treated differently in annual vs monthly outputs (for example, the annual publication can use the latest classification across the year, while monthly files use the classification in that month). NHSBSA+1

Common pitfalls and “gotchas”

A few practical caveats will save you a lot of pain when analysing PCA:

1) Dispensed in England ≠ prescribed in England

Cross-border flows exist. PCA is about where dispensing happened, not necessarily where prescribing originated. Open Data Portal+1

2) PCA is not hospital pharmacy issuing

If you are trying to understand medicines used inside hospitals (inpatient stock, ward issues), PCA is the wrong tool. PCA covers community dispensing (including hospital-origin prescriptions that are dispensed in the community), but not hospital-only dispensing. NHS BSA Open Data

3) SNOMED and supplier can disaggregate “the same BNF code”

One BNF presentation may map to multiple SNOMED/product records (often seen when supplier-specific variants exist), which can split rows in ways that surprise analysts if they assume a one-to-one mapping. NHS BSA Open Data+1

4) Known data quality notes can apply to specific months

For example, NHSBSA notes that September 2025 data incorrectly includes coronavirus vaccine data supplied through an enhanced service and will be corrected in a future update. Always scan the dataset “Important” notices before using the newest month in reporting. Open Data Portal

What is this dataset useful for?

The PCA Monthly dataset is ideal for questions like:

• Which medicines are driving NIC nationally, by region, or by ICB?
• How has uptake changed over time for a chemical substance or therapeutic area?
• Where are the biggest changes happening (e.g., sudden increases in NIC for a presentation)?
• How do branded vs generic patterns behave, using preparation class and generic equivalent fields?
• How are new services showing up in dispensing data, using the pharmacy advanced service flag? Open Data Portal+2NHS BSA Open Data+2

Because BNF hierarchy fields are included, you can answer these at:

• presentation level,
• chemical substance,
• paragraph,
• section,
• chapter,

without rebuilding the BNF tree. Open Data Portal+1

What you should not use PCA Monthly for

It is not suitable for:

• patient-level analysis (the data is aggregated, not person-level)
• determining the final cost to the NHS (NIC is not the full cost) NHS BSA Open Data
• capturing private prescribing, prison prescribing/dispensing, or hospital-only dispensing Open Data Portal+1
• analysing prescribing intent or what was written on the prescription in primary care systems (for that, NHSBSA points to the English Prescribing Dataset (EPD) as a prescribing view, which serves different needs). NHS BSA Open Data+1

Getting started: how to work with PCA Monthly

Most analysts begin with one of three approaches:

1. Download a month (CSV/ZIP) for a quick exploration (e.g., top NIC presentations in a specific ICB). Open Data Portal+1
2. Use the Data API for repeatable pipelines and dashboards (especially when you want automated monthly refresh). Open Data Portal+1
3. Build a small reference layer in your database (BNF hierarchy fields, presentation keys, geography keys) so you can write fast queries and trend charts across months.

If you plan to publish analysis, NHSBSA also provides guidance on attribution and encourages contacting their support/communications channels for press use, to reduce misinterpretation. Open Data Portal