Data Resource Profile: The Scottish National Prescribing Information System (PIS)

The Prescribing Information System (PIS) provides an infrastructure for pharmacoepidemiology and pharmacovigilance research, attracting growing attention due to its unique combination of characteristics. Compared with several databases worldwide offering national population coverage and record linkage, PIS covers all National Health Service (NHS) prescriptions prescribed, dispensed and reimbursed within the community setting, covering in Scotland a total population of 5.3 million residents. PIS provides summary information on reimbursed medicines from 1993, and it also gives access to individual prescribing and dispensing data since 2009 with the incorporation in the system of a unique number, specific to NHS Scotland, called the Community Health Index (CHI) number (the PIS evolution process is shown in Supplementary Figure 1, available as Supplementary data at IJE online). Moreover, the presence of this number allows the linkage of PIS data to other health records data, thus describing a patient’s pathway through the healthcare system. This dataset addresses the demand for longitudinal data at a population level, captured through routine clinical systems required to understand the chronology of drug use and health outcomes, complementing the evidence generated through clinical trials and drug surveillance schemes. Data resources and population coverage