Introduction to UK GO data GPRD: General Practice Research Database THIN: Health Improvement Network Some new data too

Data sources Records from GP routine records GPRD=THIN (almost) >6% of the UK population >350 GP practices >6½ million individual people

UK NHS―National Health Service Largest UK employer―4 th largest employer in world 1.7 million employees 40,000 GPs 10,000 GP practices GPs see 140 patients per week

Data content Diagnoses: GP and some hospital Biochemistry: HbA1c etc Risk factors: weight, smoking etc Family history (some) Drugs (all prescribed drugs) Outpatient contacts Free text GPRD only….linked data: Cancer registry data Hospital inpatient data

Quality: representativeness

Quality: completeness

Strengths Size―over 5% UK population Nationally representative Fast―information already collected Frequent collections All prescribable drugs Population based Study design flexibility ‘Real Life’ data―collected during normal GP visit Link to GP and patient for additional information

Weaknesses £cost! No direct link to secondary care data (THIN) No direct link of prescriptions to diagnoses - temporal implied link Limited information on OTC medications Limited data on lifestyles, diet etc Not dispensed prescriptions Limited information on hospital prescribing Some medications only administered by specialists

Weaknesses re Ca. Details of the cancer diagnosis variable No systematic cancer staging data Metastatic cancer: have to infer Hospital cancer treatments not known

New data! Survival after incident cancer: diabetes vs. non-diabetes

Incident cancers by cancer site

Incident cancers by DM treatment

Mean survival by Ca. site (years)

Δ mean survival by Ca. site (years)

Cumulative mortality (crude) DM Non-DM

Cumulative mortality (adjusted) DM Non-DM Adjusted: age, sex, smoking, morbidity

HR DM vs-N-DM (Cox)

adjHR: DM vs N-DM (=1) by treatment

Cum-mortality: ± metformin (adjusted) Met- Met+ Met- Met+ Exposed in first 3 months Exposed anytime aft Ca. diag HR=0.83; ; p< HR=0.72; ; p<