Methodology

Data Collection

Data is downloaded from official government and NHS data portals:

  • English Prescribing Data from the NHSBSA Open Data Portal — monthly CSV files containing approximately 17 million rows per month.
  • CQC ratings from the CQC Care Directory — including location details, ratings, and inspection dates.
  • GP Patient Survey results from NHS England — annual practice-level satisfaction data.
  • Practice information from the ODS Organisation Data Service.
  • BNF code classification from the NHSBSA BNF Snomed Mapping.

Data Processing

All raw data files are validated before import. We check for format changes, encoding consistency, and column mappings between different time periods. Data is stored in a SQLite database for efficient querying.

Prescribing Aggregation

Prescribing data is aggregated in several ways:

  • Practice × Drug — Total items, cost, and quantity for each practice-drug combination over 12 months, with monthly breakdowns.
  • National averages — Average items per practice for each chemical substance, enabling percentage comparisons.
  • Drug × Area — Prescribing totals by postcode area for geographic analysis.
  • Drug profiles — National totals, top prescribing practices, and monthly trends.

CQC Data

CQC ratings are matched to GP practices using the CQC Care Directory. Each practice is matched by name and postcode proximity. Ratings include the overall assessment and five individual quality dimensions.

Patient Survey

GP Patient Survey results are matched to practices using practice codes. We include overall satisfaction, contact experience, phone access, confidence, and appointment availability metrics.

Limitations

  • Prescribing data covers community prescriptions only, not hospital prescribing.
  • Some practices may not have CQC ratings or survey data available.
  • National averages include all practices, which may vary significantly in size.
  • Data currency depends on source publication schedules — prescribing data is typically 2-3 months behind.

Updates

Data is updated when new monthly prescribing data becomes available from the NHSBSA, typically on a monthly basis. CQC ratings are updated as new inspections are published.