Prevalence of serious psychiatric morbidity in attenders and nonattenders to a health survey of a general population - The Tromso Health Study

The objective was to study the effect of serious psychiatric disorders on p articipation in a general health population study. This was done by linking the records of the Second Tromso Health Study to the case register of a me ntal hospital. The participants in the Second Tromso Health Study were 21,4 41 persons, the total population of men aged 20-54 and women aged 20-49 yea rs who resided in Tromso, Norway, in 1979. The authors found that both men and women with psychiatric illness had approximately 20% lower attendance r ates. Nonattenders to the survey had 2.5 times higher prevalence of psychia tric disorders than did attenders of both sexes. Age, marital status, and v arious psychiatric diagnoses were all significant predictors of nonattendan ce. Nonattendance led to underestimation of the prevalence of psychiatric d isorders in the population. The conclusion is that in general health studie s, even those with high attendance rates, the estimates of prevalence of ps ychiatric disorders in the population are seriously affected by nonattendan ce. Prevalence ratios between groups of the population were not much affect ed by nonattendance.