The objectives of this thesis were to assess the validity of the diagnostic codes for ankylosing spondylitis and undifferentiated spondyloarthritis in the national patient register (study I), and to estimate the prevalence ...

Sudden infant death syndrome (SIDS) is still an important cause of death in infancy despite its declining incidence. The overall aim of this thesis was to study environmental factors influencing the risk of SIDS with the ...

Background: Allergic diseases such as asthma, rhinitis and eczema have increased significantly since the middle of the past century and are now common conditions among both children and adults. The increase was observed ...