Antibiotic prescribing records in two UK primary care electronic health record systems. Comparison of the CPRD GOLD and CPRD Aurum databases

ABSTRACT Objective We evaluated whether recording of antibiotic prescribing across two primary care electronic health record (EHR) systems is similar. Data were analysed from the Clinical Practice Research Datalink (CPRD) databases: CPRD GOLD (Vision data) and CPRD Aurum (EMIS data). Methods Cohorts of patients were randomly sampled from both databases, stratifying by general practice, age-group and gender. All antibiotic prescriptions in 2017 were identified. Age- and sex-standardised antibiotic prescribing rates per 1,000 person years were calculated. Prescribing of individual antibiotic products and associated medical diagnosis recorded on the same date was also evaluated. English CPRD GOLD general practices were analysed as a subgroup, because all CPRD Aurum practices sampled were in England. Results There were 101,360 antibiotic prescriptions among 158,305 sampled patients at 883 CPRD Aurum practices, and 112,931 prescriptions among 160,394 sampled patients at 290 CPRD GOLD practices. The age- and sex-standardised antibiotic prescribing rate in 2017 was 512.6 (95% confidence interval 510.4 to 514.9) per 1,000 person years in CPRD Aurum and 584.3 (582.1 to 586.5) per 1,000 person years in CPRD GOLD [505.2 (501.6 to 508.9) per 1,000 person years if restricted to practices in England]. The 25 most frequently prescribed antibiotic products were similar in both databases. One or more medical codes were recorded on the same date as an antibiotic prescription for 72,989 (74%) prescriptions in CPRD Aurum, 84,756 (78%) in CPRD GOLD, and 28,471 (78%) for CPRD GOLD in England. Skin, respiratory and genito-urinary tract infections were recorded for 39,035 (40%) prescriptions in CPRD Aurum, 41,326 (38%) in CPRD GOLD, with 15,481 (42%) in English CPRD GOLD practices only. Conclusion Similar estimates for antibiotic prescribing and infection recording were found for both databases suggesting similar recording across EMIS and Vision systems. Future research on antimicrobial stewardship can be conducted in CPRD Aurum informed by previous results from CPRD GOLD. It may also be possible to combine CPRD GOLD and CPRD Aurum data in research on antibiotic prescribing.