“…In previous empirical applications of latent class model to health care utilisation, class membership probabilities were taken as parameters π ij =π j , j=1,… ,C, to be estimated along with θ 1 , …, θ C (see e.g., Deb andTrivedi, 1997 andDeb and Holmes, 2000;Deb, 2001;Jimenez et al;, Atella et al, 2004. These can also be parameterised as functions of time invariant individual characteristics z i .…”