[Life course and institutionalization: the deceptive effect of the percentage].

At one moment in time the percentage of elderly people living in an old people's home (bejaardenoord) or nursing-home (verpleeghuis) is much higher in the Netherlands than in comparable western countries. About 11% of people 65 years of age and more are living in such institutions. However, in discussions about institutionalization, people are making the same fallacious statements based on the percentage at one moment in time as indicated in literature as "% fallacy" (Kastenbaum & Candy, 1973). In this article we have calculated that about 35% of all elderly people in the Netherlands will be institutionalized before before death. Although at one moment in time about 2% of the elderly are living in a Dutch nursing-home, the incidence is as high as in the old people's home. That is why almost the same number of elderly people will be institutionalized before death in both institutions. Three examples are given of the fallacious use of the percentage at one moment in time. An attempt is made to calculate the chance which persons have, at different ages, to be institutionalized in later life. We use the incidence-rate in 1977 and 1978 and the life expectancy inthe period 1970-1975. The results indicate high chances for elderly people at different ages to be institutionalized in later life in an old people's home.