Comparison of antibiotic prescribing records in two UK primary care electronic health record systems: cohort study using CPRD GOLD and CPRD Aurum databases.

Objectives We aimed to evaluate recording of antibiotic prescribing from two primary care electronic health record systems. Design Cohort study. Setting UK general practices contributing to the Clinical Practice Research Datalink (CPRD) databases: CPRD GOLD (Vision data) and CPRD Aurum (EMIS data). English CPRD GOLD general practices were analysed as a subgroup, as all CPRD Aurum practices were located in England. Participants 158 305 patients were randomly sampled from CPRD Aurum and 160 394 from CPRD GOLD. Outcome measures Antibiotic prescriptions in 2017 were identified. Age-standardised and sex-standardised antibiotic prescribing rates per 1000 person years were calculated. Prescribing of individual antibiotic products and associated medical diagnoses was evaluated. Results There were 101 360 antibiotic prescriptions at 883 CPRD Aurum practices and 112 931 prescriptions at 290 CPRD GOLD practices, including 112 general practices in England. The age-standardised and sex-standardised antibiotic prescribing rate in 2017 was 512.6 (95% CI 510.4 to 514.9) per 1000 person years in CPRD Aurum and 584.3 (582.1 to 586.5) per 1000 person years in CPRD GOLD (505.2 (501.6 to 508.9) per 1000 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 genitourinary 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 Estimates for antibiotic prescribing and infection recording were broadly similar in both databases suggesting similar recording across EMIS and Vision systems. Future research on antimicrobial stewardship can also be conducted using primary care data in CPRD Aurum.