← Back to Portfolio

NHS Data Integration Pipeline

Data Engineering

Multi-source healthcare data integration system with ETL pipeline architecture, star schema modeling, and NHS data standards compliance (620k records, 207MB).

NHS Data Integration Pipeline screenshot 1

Overview

💡 Challenge

NHS Trusts have patient data scattered across multiple isolated systems (PAS, EHR, LIMS, Appointments) that do not communicate. Clinicians lack complete patient journey visibility, and analysts cannot perform system-wide analysis for service improvement.

⚡ Solution

Designed and built comprehensive ETL pipeline integrating 4 NHS source systems into unified star schema data warehouse. System handles multi-format data (CSV, JSON), validates NHS-specific standards (Modulus 11 check digits, ICD-10 codes), and implements GDPR-compliant architecture with data quality framework.

🎯 Impact

Demonstrates capabilities directly applicable to analyzing Scotland's Unscheduled Care Data Mart (UCD) for patient pathway optimization. Architecture supports 620,320 records with <2hr processing time, 99.5% data quality target, and complete audit trail for healthcare analytics and research.

Technical Details

🛠️ Tech Stack

PythonPandasDuckDBSQLETLData ModelingStar SchemaNHS StandardsData QualityGDPRHealthcare Analytics

✨ Key Features

  • Multi-source data extraction from 4 NHS clinical systems
  • Star schema dimensional warehouse with fact and dimension tables
  • Valid NHS number generation using Modulus 11 algorithm
  • ICD-10 diagnosis coding and clinical terminology standards
  • Data quality validation framework with healthcare-specific rules
  • GDPR-compliant design with pseudonymization and audit trails
  • Synthetic data generation: 50k patients, 100k encounters, 350k lab results, 120k appointments
  • Realistic healthcare data patterns with intentional quality issues
  • Five-layer architecture: Source → Staging → Processing → Warehouse → Presentation
  • Handles multiple data formats (CSV for structured, JSON for clinical notes)
  • Scottish healthcare demographics and geographic data
  • Performance targets: <2hr processing, 10M+ records daily capacity
  • Complete documentation of data dictionary and quality rules
  • ETL pipeline design ready for Apache Airflow orchestration

Key Learnings

  • Healthcare data integration requires deep understanding of clinical workflows and terminology standards
  • Star schema dimensional modeling dramatically simplifies complex patient pathway analytics queries
  • NHS number validation with Modulus 11 algorithm essential for data quality in UK healthcare systems
  • Synthetic data generation must preserve realistic correlations between clinical variables
  • GDPR compliance requires pseudonymization strategy, not just encryption
  • Data quality framework must balance completeness checks with realistic missing data patterns
  • Multi-format data handling (CSV, JSON) required for different NHS system characteristics
  • Five-layer architecture provides clear separation of concerns for maintainability and testing
  • Documentation of data lineage and transformation logic critical for healthcare audit requirements

📊 Data Notes

This project uses synthetic/open data to demonstrate capabilities while maintaining privacy and confidentiality. All methods and approaches are applicable to real-world scenarios.

Portfolio | Ayoolumi Oluwafemi Melehon