The influence of prescription drug insurance on psychotropic and non-psychotropic drug utilization in Canada.

Using 2002 Canadian Community Health Survey data, this paper examines the effect of public and private prescription drug insurance on the utilization of psychotropic and non-psychotropic drugs. It is found that prescription drug utilization is characterized by two stochastic regimes requiring use of latent class modelling framework. In many instances, results differ for the classes of high and low users of prescription drugs. After accounting for the unobserved individual heterogeneity and a number of socio-demographic factors, health status, and province fixed effects, we find that having prescription drug insurance (public or private) increases the expected number of non-psychotropic medications for both low and high users. Public insurance affects psychotropic drug utilization positively for the low-user group only. The statistical insignificance of insurance for the high-user psychotropic drugs or lower magnitude of insurance coefficients on high-user non-psychotropic drugs seems to stem from high inelastic demand for prescription drugs in the concerned groups. In addition, we find that age, self-reported health status, and long-term mental and physical health problem diagnosed by a health professional are important determinants of prescription drug utilization for both classes of users.