Using Latent class analysis (LCA) to analyze patterns of drug use in a population of illegal opioid users

The University of Calgary, Calgary, Alberta, Canada
Drug and Alcohol Dependence (Impact Factor: 3.42). 05/2007; 88(1):1-8. DOI: 10.1016/j.drugalcdep.2006.08.029
Source: PubMed


The objective of this paper is to empirically determine a categorization of illegal opioid users in Canada in order to describe and analyze drug use patterns within this population.
Drug use patterns of 679 eligible illegal opioid users outside treatment from the OPICAN study, a pan-Canadian cohort (recruited March to December, 2002) involving the cities of Toronto, Montreal, Vancouver, Edmonton and Quebec City, were empirically examined using latent class analysis. These latent classes were then further analyzed for associations using chi-square and t-test statistics.
The opioid and other drug user sample surveyed were categorized into three latent classes. Class 1 (N=256) was characterized by the use of Tylenol 3 and benzodiazepines along with high levels of depression and self-reported pain. Class 2 (N=68) was described by the non-injection use of both heroin and crack while having a high level of homelessness. Class 3 (N=344) was shown to consist of injection drug users of heroin and cocaine exhibiting the highest levels of HIV and Hepatitis C infections amongst the classes.
Using latent class analysis we found distinct patterns of drug use amongst illegal opioid users differing in terms of type of drugs co-used, social context, and co-morbid pathologies. These data may be useful as the empirical basis for the planning of specific prevention and treatment interventions.

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    • "Among illicit opioid users in a multisite study in Canada, Monga et al. (2007) found a polydrug use class of heroin and cocaine injectors that had higher rates of overdose than the two other classes. In the same sample, Patra et al. (2009) also found several classes of concurrent opioid and stimulant use. "
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    • "To date, at least one study has used LCA to distinguish subtypes of drug users beyond pharmacological properties, based on the route and type of drugs. This study was conducted in Canada and found three classes: one class that consisted of high use of Tylenol 3 and benzodiazepine with a high rate of depression and pain, a second included non-injectors and crack smokers, and a third consisted of injection drug users (IDUs) with a high rate of HIV and Hepatitis C (Monga et al., 2007). An extension of this study using a more recent sample found eight classes (Patra et al., 2009). "
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