The dataset consists of longitudinal measures of bone score during puberty, where 1000 indicates maturity. The aim is to estimate median age at maturity in four groups by sex and ethnicity.

This glm code works fine, but ignores the longitudinal element.
lm2 <- glm(I(RUSBoneScore == 1000) ~ log(DecAge) + Sex * Ethnicity, family=binomial, data=na.omit(bh[, 3:6]))

This code, which adds a random subject effect, fails with the unhelpful error message below.
lm3 <- glmer(I(RUSBoneScore == 1000) ~ log(DecAge) + Sex * Ethnicity + (1 | BHID), family=binomial, data=na.omit(bh[, 2:6]))

Error in pwrssUpdate(pp, resp, tolPwrss, GHrule(0L), compDev, verbose) :
  c++ exception (unknown reason)

I've tried various alternatives but they all fail in the same way. Thoughts please.

Thanks,
Tim Cole
--
Tim.Cole@ucl.ac.uk<mailto:Tim.Cole@ich.ucl.ac.uk> Phone +44(0)20 7905 2666 Fax +44(0)20 7905 2381
Centre for Paediatric Epidemiology and Biostatistics
UCL Institute of Child Health, London WC1N 1EH, UK


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