A fleet of packages for inputting United Kingdom primary care data

The Clinical Practice Research Datalink (CPRD) is a centrally-managed data warehouse, storing data provided by the primary-care sector of the United Kingdom (UK) National Health Service (NHS). Medical researchers request retrievals from this database, which take the form of a collection of text datasets, whose format can be complicated. I have written a flagship package cprdutil, with multiple modules to input into Stata the many text dataset types provided in a CPRD retrieval. These text datasets may be converted either to Stata value labels or to Stata datasets, which can be created complete with value labels, variable labels, and numeric Stata dates. I have also written a fleet of satellite packages, to input into Stata the text datasets for retrievals of linked data, in which data are provided from non-CPRD sources, with CPRD identifier variables as a foreign key to allow data linkage. The modules of cprdutil are introduced. A demonstration example is given, in which a minimal CPRD database is produced in Stata, using cprdutil, and some principles of sensible programming practice for creating large databases are illustrated.