The tooth data was from a longitudinal prospective dental study performed in Flanders (Belgium) in 1996 -- 2001. Every one of 4,386 randomly sampled children in the cohort was examined annually by one of 16 trained dentists, resulting at most 6 dental observations for each child. The outcome of interest was the time to emergence of permanent tooth 24, which was either interval censored (2,775, 63%) or right censored (1,611, 37%).
tooth is a data frame with 4,386 observations and 7 columns
children's id;
left censoring time;
right censoring time where infinity is coded as 999.
gender of children (0 = boy, 1 = girl);
status of the primary predecessor of this tooth (0 = sound, 1 = delayed, missing or filled);
right censoring time where infinity is coded as
Inf;
right censoring time where infinity is coded as
NA.
tooth.grid is a numeric vector of grid time points.
J. Vanobbergen, L. Martens, D. Declerck, and M. Lesaffre (2000). The signal tandmobiel(r) project: a longitudinal intervention oral health promotion study in Flanders (Belgium): baseline and first year results. European Journal of Paediatric Dentistry 2, 87.
G. Gomez, M. Calle, R. Oller, and K. Langohr (2009). Tutorial on methods for interval-censored data and their implementation in R. Statistical Modeling 9(4), 259.