R: Dental Data

dmft {flexmix} | R Documentation

## Dental Data

### Description

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).

### Usage

    data("dmft")

### Format

A data frame with 797 observations on the following 5 variables.

End

  Number of decayed, missing or filled teeth at the end of the study.

Begin

  Number of decayed, missing or filled teeth at the beginning of the study.

Gender

  A factor with levels `male` and `female`.

Ethnic

  A factor with levels `brown`, `white` and `black`.

Treatment

  A factor with levels `control`, `educ`, `enrich`, `rinse`, `hygiene` and `all`.

### Details

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

  Control group

educ

  Oral health education

enrich

  Enrichment of the school diet with rice bran

rinse

  Mouthwash with 0.2% sodium floride (NaF) solution

hygiene

  Oral hygiene

all

  All four methods together

### Source

D. Boehning, E. Dietz, P. Schlattmann, L. Mendonca and U. Kirchner. 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), 195–209, 1999.

### Examples

    data("dmft", package = "flexmix")
    dmft_flx <- initFlexmix(End ~ 1, data = dmft, k = 2,
                            model = FLXMRglmfix(family = "poisson",
                            fixed = ~ Gender + Ethnic + Treatment))

[Package flexmix version 2.3-14 Index]