Table 2

Examples of enrichment that can be enabled via linkages of the clinical rheumatology registers to other national and population-based registers

Population (million)
Conditions for register linkages
 Individual informed consentGenerally not for register-only studiesNot for epidemiological researchDepending on Ethics Review Board assessment of individual projectsNot for register studies by permission from the National Institute for Health and Welfare ad 2020Not for epidemiological research
 ApprovalsEthics Review Board, approval from each register holderApproval from the data protection agency and from registry holderEthics Review Board, approval from each register holderEthics Review board and the National Institute for Health and WelfareApproval from the National Bioethics Committee, Data Protection Authority and from registry holders
 Time from application to data delivery6–12 months<6 months6–12 months12 months<6 months
Hospitalisations, in-patient careThe Swedish Patient Register 1987The National Patient Registry 1977The Norwegian Patient Register 2008Hospital Finnish Discharge Register 1998The Icelandic National Patient Registry 1999
Outpatient visits in specialised careThe Swedish Patient Register 2001The National Patient Registry 1995The Norwegian Patient Register 2008Hospital discharge register 1998No
Primary careYes, for three regions (50% of country)NoNoNoNo
Vital status, residency, civil statusThe Population Register: 1962The Civil Registration System 1968The National Registry: 1946Population register (date of death) 1969The Population Register 1914
Cause of deathThe Death Register 1952The Causes of Death Registry 1943The Cause of Death Registry 1951NoThe Causes of Death Registry 1971
CancerThe Cancer Registry 1958The Cancer Registry 1942The Cancer Registry 1951The Cancer Registry 1952The Cancer Registry 1954
Prescribed drugsThe Prescribed Drug Register 2005The Danish National Database of Reimbursed Prescriptions 2004The Prescription Database 2004Co-payment register 2007The Medicinal Dispense Registry 2002
Education and occupationThe Education Register 1960Dutch Rheumatoid Arthritis Monitoring Registry 1991The National Education Database 1970NoNo
Sick leave, disability pensionThe Social Insurance Agency Register (MIDAS) 1992 and LISA 1990IDA registry 1980The Labour and Welfare Administration 2008The registers for sick leaves, pensions and rehabilitation 2000The Social Insurance Administration 1997
  • LISA, Longitudinal Database for health insurance and labor market studies; MiDAS, Swedish Social Insurance Agency’s database Micro Data for Analysis of Social Insurance.