RT Journal Article SR Electronic T1 Spatial distribution of clinical computer systems in primary care in England in 2016 and implications for primary care electronic medical record databases: a cross-sectional population study JF BMJ Open JO BMJ Open FD British Medical Journal Publishing Group SP e020738 DO 10.1136/bmjopen-2017-020738 VO 8 IS 2 A1 Evangelos Kontopantelis A1 Richard John Stevens A1 Peter J Helms A1 Duncan Edwards A1 Tim Doran A1 Darren M Ashcroft YR 2018 UL http://bmjopen.bmj.com/content/8/2/e020738.abstract AB Objectives UK primary care databases (PCDs) are used by researchers worldwide to inform clinical practice. These databases have been primarily tied to single clinical computer systems, but little is known about the adoption of these systems by primary care practices or their geographical representativeness. We explore the spatial distribution of clinical computing systems and discuss the implications for the longevity and regional representativeness of these resources.Design Cross-sectional study.Setting English primary care clinical computer systems.Participants 7526 general practices in August 2016.Methods Spatial mapping of family practices in England in 2016 by clinical computer system at two geographical levels, the lower Clinical Commissioning Group (CCG, 209 units) and the higher National Health Service regions (14 units). Data for practices included numbers of doctors, nurses and patients, and area deprivation.Results Of 7526 practices, Egton Medical Information Systems (EMIS) was used in 4199 (56%), SystmOne in 2552 (34%) and Vision in 636 (9%). Great regional variability was observed for all systems, with EMIS having a stronger presence in the West of England, London and the South; SystmOne in the East and some regions in the South; and Vision in London, the South, Greater Manchester and Birmingham.Conclusions PCDs based on single clinical computer systems are geographically clustered in England. For example, Clinical Practice Research Datalink and The Health Improvement Network, the most popular primary care databases in terms of research outputs, are based on the Vision clinical computer system, used by <10% of practices and heavily concentrated in three major conurbations and the South. Researchers need to be aware of the analytical challenges posed by clustering, and barriers to accessing alternative PCDs need to be removed.