Strategy for identifying insulin pump use in Clinical Practice Research Datalink GOLD

BackgroundClinical Practice Research Datalink (CPRD) GOLD is an invaluable resource for clinical research. However, some exposures are difficult to capture, including continuous subcutaneous insulin infusion pump systems ("insulin pumps"). We present a strategy we developed to classify insulin pump users and to estimate the duration of pump use in CPRD GOLD. This was done to study adverse skin events in new adult pump users. MethodsInsulin pump users were defined as patients who had a specific insulin pump code (prescription for an insulin pump cartridge or clinical code for continuous insulin infusion) in their record. Duration of use was defined as the continuous use of any insulin formulation commonly used in pump systems before and after the insulin pump specific code. Each patients pump start and end dates were calculated programmatically and then confirmed by manual review of the patients CPRD record. ResultsThere were 1032 patients with an insulin pump specific code recorded in CPRD GOLD through December 2018, of which 302 met the inclusion criteria for our safety study. Due to high variability in the patterns of insulin use, programmatic determination of pump start and end dates was insufficient. The start and/or end dates of >50% of patients required adjustment upon manual review. ConclusionsInsulin pump users in CPRD GOLD could be easily identified using this strategy, but we may have missed additional insulin pump users without specific pump codes. The duration of pump use, however, was difficult to capture. This strategy, though time intensive, is a useful tool for the study of insulin pumps. FundingThis study was funded by AbbVie. Conflicts of Interest StatementBoston Collaborative Drug Surveillance Program (BCDSP) received funding from AbbVie for this study. Susan Jick and Rebecca Persson are employees of BCDSP. Todd Sponholtz and Brenda Baak were interns at BCDSP. Authors retain full and scientific control over the content of this manuscript. DisclosuresThis manuscript has not been peer-reviewed. We provide this information as a reference for other users of Clinical Practice Research Datalink GOLD. This study is based in part on data from the Clinical Practice Research Datalink obtained under license from the UK Medicines and Healthcare products Regulatory Agency. The data is provided by patients and collected by the NHS as part of their care and support. The interpretation and conclusions contained in this study are those of the authors alone. This study was approved by the Independent Scientific Advisory Committee (ISAC) for Medicines and Healthcare products Regulatory Agency (protocol no: 19_216R).