Re.: 'The health status of nonparticipants in a population-based health study: the Hordaland Health Study'.

摘要

In their interesting article in which they compared the health of participants with that of nonparticipants in a population-based survey in Norway, Knudsen et al. (1) were able to link their eligible population sample with the Norwegian national registry of disability pensions, which includes information about diagnoses. They found that the likelihood of receiving a disability pension was higher among nonparticipants, and this was especially true for persons receiving disability pensions as a result of mental disorders. One of the most important features of their study was that the use of a registry-based outcome provided information on health status several years after inception, and the authors claim that "this was the first study to obtain information about nonpar-ticipation bias using a longitudinal design" (1, p. 1310).