The data are from the Muscatine Coronary Risk Factor (MCRF) study, a longitudinal survey of school-age children in Muscatine, Iowa. The MCRF study had the goal of examining the development and persistence of risk factors for coronary disease in children. In the MCRF study, weight and height measurements of five cohorts of children, initially aged 5-7, 7-9, 9-11, 11-13, and 13-15 years, were obtained biennially from 1977 to 1981. Data were collected on 4856 boys and girls. On the basis of a comparison of their weight to age-gender specific norms, children were classified as obese or not obese.
A dataframe with 14568 rows and 7 variables:
identifier of child.
gender of child
identifier of occasion of recording
'yes' or 'no'
obese in numerical form: 1 corresponds to 'yes' and 0 corresponds to 'no'.
Woolson, R.F. and Clarke, W.R. (1984). Analysis of categorical incompletel longitudinal data. Journal of the Royal Statistical Society, Series A, 147, 87-99.
muscatine$cage <- muscatine$age - 12 muscatine$cage2 <- muscatine$cage^2 f1 <- numobese ~ gender f2 <- numobese ~ gender + cage + cage2 + gender:cage + gender:cage2 gee1 <- geeglm(formula = f1, id = id, waves = occasion, data = muscatine, family = binomial(), corstr = "independence") gee2 <- geeglm(formula = f2, id = id, waves = occasion, data = muscatine, family = binomial(), corstr = "independence") tidy(gee1) tidy(gee2) QIC(gee1) QIC(gee2)