tandmob {icensBKL}

Signal Tandmobiel Data, Subsample

Description

This is a random sample of 500 children (256 boys and 244 girls) from the dataset resulting from a longitudinal prospective dental study performed in Flanders (North of Belgium) in 1996 – 2001. The cohort of 4 468 randomly sampled children who attended the first year of the basic school at the beginning of the study was annualy dental examined by one of 16 trained dentists. The original dataset consists thus of at most 6 dental observations for each child.

The dataset presented here contains mainly the information on the emergence and caries times summarized in the interval-censored observations. In addition to the interval censored observation of the emergence time of several teeth, a random visit was selected in order to create current status data of the emergence times for the same children. Also the time to caries of the four permanent first molars are included in the data set. Finally, the covariates gender, frequency of brushing, the presence of sealants and occlusal plaque on the first permanent molars collected in the first year were included as potential confounders in the data set.

For more detail on the design of the study see Vanobbergen et al. (2000).

Usage

data(tandmob)

Format

a data frame with 500 rows and the following variables

IDNR

identification number of a child.

GENDER

numeric gender; 0=boy, 1=girl.

fGENDER

factor derived from a variable GENDER.

DMF_1

dmft-score at baseline around the age of 7 years.

OH16o, OH26o, OH36o, OH46o

numeric occlusal plaque status of teeth 16, 26, 36, 46 (permanent first molars); 0=no plaque, 1=pits/fissures, 2=total.

fOH16o, fOH26o, fOH36o, fOH46o

factors derived from variables OH16o, OH26o, OH36o, OH46o.

BRUSHING

numeric brushing frequency at baseline; 0=less than daily, 1=at least once a day.

fBRUSHING

factor derived from a variable BRUSHING.

SEAL16, SEAL26, SEAL36, SEAL46

numeric baseline presence of sealing on teeth 16, 26, 36, 46 (permanent first molars); 0=no, 1=yes.

fSEAL16, fSEAL26, fSEAL36, fSEAL46

factors derived from variables SEAL16, SEAL26, SEAL36, SEAL46.

DMF_54, DMF_64, DMF_74, DMF_84

numeric baseline dmft score of teeth 54, 64, 74, 84 (primary first molars); 0=sound, 1=caries experience.

DMF_55, DMF_65, DMF_75, DMF_85

numeric baseline dmft score of teeth 55, 65, 75, 85 (primary second molars); 0=sound, 1=caries experience.

fDMF_54, fDMF_64, fDMF_74, fDMF_84

factors derived from variables DMF_54, DMF_64, DMF_74, DMF_84.

fDMF_55, fDMF_65, fDMF_75, fDMF_85

factors derived from variables DMF_55, DMF_65, DMF_75, DMF_85.

L14, L24, L34, L44

left (lower) limit of observed emergence time of teeth 14, 24, 34, 44 (permanent first premolars), NA for left-censored observations.

R14, R24, R34, R44

right (upper) limit of observed emergence time of teeth 14, 24, 34, 44 (permanent first premolars), NA for right-censored observations.

L15, L25, L35, L45

left (lower) limit of observed emergence time of teeth 15, 25, 35, 45 (permanent second premolars), NA for left-censored observations.

R15, R25, R35, R45

right (upper) limit of observed emergence time of teeth 15, 25, 35, 45 (permanent second premolars), NA for right-censored observations.

L16, L26, L36, L46

left (lower) limit of observed emergence time of teeth 16, 26, 36, 46 (permanent first molars), NA for left-censored observations.

R16, R26, R36, R46

right (upper) limit of observed emergence time of teeth 16, 26, 36, 46 (permanent first molars), NA for right-censored observations.

CS_age

age at visit selected to determine current status.

CS_14, CS_24, CS_34, CS_44

numeric current status of teeth 14, 24, 34, 44 (permanent first premolars) at age given by variable CS_age; 0=not emerged, 1=emerged.

fCS_14, fCS_24, fCS_34, fCS_44

factors derived from variables CS_14, CS_24, CS_34, CS_44.

CL16, CL26, CL36, CL46

left (lower) limit of observed time to caries of teeth 16, 26, 36, 46 (permanent first molars), NA for left-censored observations.

CR16, CR26, CR36, CR46

right (upper) limit of observed time to caries of teeth 16, 26, 36, 46 (permanent first molars), NA for right-censored observations.

Source

Leuven Biostatistics and Statistical Bioinformatics Centre (L-Biostat), Katholieke Universiteit Leuven, Kapucijnenvoer 35, 3000 Leuven, Belgium

URL: http://med.kuleuven.be/biostat/

Data collection was supported by Unilever, Belgium. The Signal Tandmobiel project comprises the following partners: D. Declerck (Dental School, Catholic University Leuven), L. Martens (Dental School, University Ghent), J. Vanobbergen (Oral Health Promotion and Prevention, Flemish Dental Association), P. Bottenberg (Dental School, University Brussels), E. Lesaffre (Biostatistical Centre, Catholic University Leuven), K. Hoppenbrouwers (Youth Health Department, Catholic University Leuven; Flemish Association for Youth Health Care).

References

Carvalho, J. C., Ekstrand, K. R., and Thylstrup, A. (1989). Dental plaque and caries on occlusal surfaces of first permanent molars in relation to stage of eruption. Journal of Dental Research, 68, 773–779.

Vanobbergen, J., Martens, L., Lesaffre, E., and Declerck, D. (2000). The Signal-Tandmobiel project – a longitudinal intervention health promotion study in Flanders (Belgium): baseline and first year results. European Journal of Paediatric Dentistry, 2, 87–96.

Examples

data("tandmob", package="icensBKL")
summary(tandmob)