Summary of LTA.

#Item response probability is the probability to choose an item conditional on the persons' latent class membership. For example, in the question ‘number of friends of boys as affected by smoking’, a participant in Class 1 would have a 0.98 probability to select ‘Less’, 0.02 to select ‘Indifferent’ and 0.01 to select ‘More’. These probabilities help interpreting the latent classes and are conceptually similar to factor loadings in factor analysis. For detailed technical specifications, please refer to Lanza et al and Rindskopf [41], [42].