Aa. Schuller et D. Holst, INCREASING NUMBER OF TEETH PRESENT IN A QUASI-LONGITUDINAL STUDY IN ADULTS - A METHODOLOGICAL NOTE, Community dentistry and oral epidemiology, 26(3), 1998, pp. 209-213
Citations number
6
Categorie Soggetti
Dentistry,Oral Surgery & Medicine","Public, Environmental & Occupation Heath
This paper discusses the impossible result of an increase in the numbe
r of teeth present in a quasi-longitudinal study of an adult populatio
n. In 1983 and 1994, random samples were drawn from birth cohorts 1939
-48 and 1930-38. The paradoxical result that adults acquired new teeth
in the quasi-longitudinal study gave rise to questions about the comp
arability of the two samples. Four main sources of failure in comparab
ility are described and discussed: instrumental stability, criteria co
nsistency, response bias, and compositional change in aging cohorts. T
he lower response rate among persons with two edentulous jaws, and pos
sibly among persons with one dentate jaw, was concluded to be the main
reason for the increase in the overall group median and mean number o
f teeth present. In general, in studies with a similar study design, p
roblems of comparability between the samples demand one's attention an
d should therefore be carefully evaluated. Compositional change of the
population as a source of failure in sample comparability cannot be a
voided, while the other three sources (instrumental stability, criteri
a consistency, response bias) can largely be avoided by careful planni
ng and efficient use of resources.