dmft {flexmix} | R Documentation |
Count data from a dental epidemiological study for evaluation of various programs for reducing caries collected among school children from an urban area of Belo Horizonte (Brazil).
data("dmft")
A data frame with 797 observations on the following 5 variables.
Number of decayed, missing or filled teeth at the end of the study.
Number of decayed, missing or filled teeth at the beginning of the study.
A factor with levels male
and female
.
A factor with levels brown
, white
and black
.
A factor with levels control
, educ
, enrich
,
rinse
, hygiene
and all
.
The aim of the caries prevention study was to compare four methods to prevent dental caries. Interventions were carried out according to the following scheme:
Control group
Oral health education
Enrichment of the school diet with rice bran
Mouthwash with 0.2% sodium floride (NaF) solution
Oral hygiene
All four methods together
D. Boehning, E. Dietz, P. Schlattmann, L. Mendonca and U. Kirchner (1999): The zero-inflated Poisson model and the decayed, missing and filled teeth index in dental epidemiology. Journal of the Royal Statistical Society A 162(2), pages 195-209.
data("dmft") dmft.flx <- stepFlexmix(End ~ 1, data = dmft, k = 2, model = FLXMRglmfix(family = "poisson", fixed = ~ Gender + Ethnic + Treatment))