Cohort profile: the Swedish Prescribed Drugs and Health Cohort (SPREDH)

PURPOSE: The Swedish Prescribed Drugs and Health Cohort (SPREDH) is a Swedish population-based cohort based on data from four nationwide health data registers, created with the aim of investigating how the use of selected medications influences cancer risk and other outcomes. PARTICIPANTS: The cohort includes 8 421 115 users of selected common medications who have been followed-up for a total of 82 281 720 person-years from 1 July 2005 to 31 December 2015. FINDING TO DATE: The data in SPREDH were prospectively collected from the following national health data registers in Sweden: Prescribed Drug Register, Patient Register, Cancer Register and Causes of Death Register. Data on basic patient characteristics, use of the selected common medications, healthcare utilisation, diagnoses (including detailed information on cancers), and dates and causes of death are available for all cohort participants. The cohort currently includes 801 766 incident cancer cases. FUTURE PLANS: The data in SPREDH can be used for various types of epidemiological research, particularly for examining how the use of the selected medications influences disease risk and other outcomes. We are initially planning cohort studies and nested case-control studies on selected medications in relation to the risk and prognosis of oesophageal and gastric cancers.