The Swedish Prescribed Drugs and Health Cohort (SPREDH) is a population-based cohort based on merged data from four nationwide health data registers in Sweden. SPREDH provides opportunities to investigate how the use of various medications influences cancer risk, cancer prognosis and many other outcomes. The cohort was recently updated to include a longer follow-up, more patients and additional drugs.

SPREDH currently includes 9 454 340 users of selected medications, who have been followed up for a total of 138 015 003 person-years from 1 July 2005 to 31 December 2024, that is, for up to 191/2 years.

SPREDH includes data from the Swedish Prescribed Drug Register, Patient Register, Cancer Register and Cause of Death Register. Available data include participants’ characteristics, use of medication, healthcare utilisation, diagnoses (including detailed information on cancers), surgical procedures and dates and causes of death. The original version of SPREDH has been used for 10 original studies published in scientific journals, primarily in the fields of gastroenterology and oncology. The updated version of SPREDH includes 1 382 698 participants who have developed a cancer during the follow-up.

The newly updated and extended version of SPREDH enables studies with a wide range of study designs and hypotheses, especially pharmacoepidemiological studies evaluating how the use of certain medications affects the risk and prognosis of cancer and other diseases. It also allows for comparative research across classes of medications, as well as investigations of drug utilisation, safety and effectiveness.