1. © Imperial College LondonPage 1 Professor Azeem Majeed Department of Primary Care & Social Medicine, Faculty of Medicine, Imperial College London. “Using Primary Care Data for Epidemiological and Health Services Research” In the chair: Professor Paul Elliott, Faculty of Medicine, Imperial College London Vote of thanks: Sir Denis Pereira Gray, Chairman of the Nuffield Trust Imperial College London Inaugural Lecture www.imperial.ac.uk/events

2. © Imperial College LondonPage 2 Outline of talk Professional background Why is primary care data needed? What data are available Use of primary care data for research Benefiting from NHS IT programme

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7. © Imperial College LondonPage 7 Why is primary care data needed? Help clinicians provide care Plan health services & monitor targets Measure clinical performance Measure health service utilisation Monitor inequalities Health services research & clinical epidemiology, & clinical trials

8. © Imperial College LondonPage 8 Eminent previous researchers John Fry Julian Tudor Hart Sir Brian Jarman

9. © Imperial College LondonPage 9 Data collected in primary care Collected through day to day clinical work of GPs, nurses and other professionals Additional data sent electronically to practices or added to medical records by primary care staff

10. © Imperial College LondonPage 10 Data collected on primary care NHS activity data Workload, screening, immunisation Prescribing Referrals & admissions Waiting times NHS spending

11. © Imperial College LondonPage 11 Strengths of primary care data Population based Most contacts with NHS take place in primary care Information on most aspects of care (morbidity, investigations, treatment, outcomes & utilisation) Increasingly available for analysis in computerised format

12. © Imperial College LondonPage 12 Weaknesses of primary care data Often comes from volunteer practices & hence may not be representative Quality & completeness of data recording varies widely Lack of socio-economic & ethnic data Multiple clinical systems, not currently linked to hospital systems Can be difficult & expensive to access

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17. © Imperial College LondonPage 17 Change in antibiotic prescribing 1995-1998: GPRD

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21. © Imperial College LondonPage 21 Comorbidity (relative risk) in AF patients 45-64 yrs65-74 yrs75+ yrs IHD4.52.62.5 Heart failure 33.57.53.7 Raised BP2.51.41.5 Diabetes1.61.41.1 Stroke8.63.22.9

22. © Imperial College LondonPage 22 Age and sex specific prevalence (%) of congenital heart disease, 2005

23. © Imperial College LondonPage 23 Survival estimates by congenital heart disease severity group 5444 patients born from 1 Jan 1990 included in survival analysis 42,566 person years at risk 82 deaths observed SimpleModerateComplexAll CHD Survival probability 95% CI Survival probability 95% CI Survival probabilit y 95% CI Survival probabilit y 95% CI (%)LLUL(%)LLUL(%)LLUL(%)LLUL 1 year 99.899.699.999.899.199.998.596.199.499.699.499.7 5 year 99.198.799.399.098.099.592.888.895.498.698.398.9 10 year98.898.499.298.597.399.291.887.294.898.397.898.7

24. Page 24 % Patients Referred/Year UK US Health Plans

25. © Imperial College LondonPage 25 Recent developments New GP contract from 1-4-2004 Quality payments for 10 clinical areas CHD, stroke, hypertension, hypothyroidism, diabetes, mental health, chronic obstructive pulmonary disease, asthma, epilepsy, cancer New clinical areas added in 2006 Old GP clinical systems will be replaced

26. © Imperial College LondonPage 26 Examples of data items The practice can produce a register of patients with CHD, [CHD 1] The percentage of patients with CHD whose notes have a record of blood pressure in the previous 15 months, [CHD 5]

27. © Imperial College LondonPage 27 Limitations Quality of data Exception coding Prevalence of disease by age, sex and ethnicity not available Prevalence of co-morbidity among patients Prevalence of risk factors e.g. smoking status, BMI, ethnicity

28. © Imperial College LondonPage 28 National prevalence (England)

29. © Imperial College LondonPage 29 National data (England): clinical domains http://www.ic.nhs.uk/services/qof/statisticalbulletin/Bulletin.PDF

30. © Imperial College LondonPage 30 Percentage of patients with diabetes with HbA1C <=7.4 mmol/L in last 15 months

31. © Imperial College LondonPage 31 Percentage of patients with diabetes with HbA1C <=7.4 mmol/L in last 15 months

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39. © Imperial College LondonPage 39 Secondary Uses Service Aim to provide timely information for purposes other than direct patient care e.g. planning, commissioning, clinical governance, research, Construct population based indicators of incidence, prevalence and utilisation

40. © Imperial College LondonPage 40 Research potential Disease registers to use as sampling frames for clinical trials Follow-up data for clinical trials and epidemiological studies Monitoring adverse events Case-mix measurement & risk adjustment Health services research, e.g. inequalities

41. © Imperial College LondonPage 41 Adverse drug reactions Rely on doctors’ reports Very low ascertainment (<10%) Failure to detect side-effects quickly has major consequences (e.g. Vioxx)

42. © Imperial College LondonPage 42 New methods of detecting adverse drug reactions Prospective instead of retrospective Monitor diagnoses associated with patients on specific drugs Use data mining and signal detection Investigate positive signals quickly Implement changes to policy Patients for pharmacogenetic studies

43. © Imperial College LondonPage 43 Technical challenges Extraction of data from multiple clinical systems in general practice Linkage of data, e.g. with hospital data Dealing with variations in accuracy and completeness Very large volumes of data need to be processed and analysed Ethical and legal issues

44. © Imperial College LondonPage 44 Conclusions Primary care data important Provide information on the population Advances in NHS IT will make more data available Some developmental work needed to take advantage of future data streams Collaboration between academics, industry, NHS, clinicians

45. © Imperial College LondonPage 45 Paul Elliott & Sir Denis Pereira GrayManor Health Centre, Clapham, London Imperial CollegeBattersea Research Group University of Wales College of MedicineWandsworth Research Centre Ashgrove Surgery PontypriddWest London Research Network East Glamorgan HospitalKent, Surrey, Sussex Research Network Gloucester Health AuthorityDr Foster Intelligence Gloucester Public Health LaboratoryMerton, Sutton & Wandsworth HA St. George’s Hospital Medical SchoolBrent PCT & NWLH NHS Trust Office for National StatisticsDiabetes Research Network University College LondonDepartment of Health