Analysis of the latency period between the first cocaine use and the first request for treatment: a pilot study in Liguria region

Background: The aim of this study is to estimate the distribution of the period between the time of first use of cocaine and the time of first contact with a Drug Addiction Service and to evaluate the effects of some covariates (such as gender and age at first use of cocaine) on this time lag, defined as "latency period".Methods: Survival analysis was used to study the distribution of time of occurrence of a specific event in a specific population and to analise how this time varies related to specific population characteristics. Results: The analysis of the variable "age at first cocaine use" points out average latency times approximately around 9 years among those with onset of cocaine use before 20 years of age, 6 years among those with onset after 21 years of age. Latency period vary also according to the gender: 4 years among females and 8 years among males. According to the univariate analysis, results of the Weibull regression model show that women and those starting cocaine use after 21 years of age have more probability to claim earlier (respectively 80% and 60% related to the reference groups) the first treatment related to cocaine use.Conclusions: The distribution estimate of the time lag between the first use of cocaine and the first treatment demand constitutes a good epidemiological indicator of the attractiveness and rapidity of first treatment activation on behalf of the public health service, addressed to subjects with substance related problems. This pilot study points out that the distribution of the latency period is influenced both by gender and age at first use of cocaine; therefore women and those who began taking cocaine in the later years, are more likely to claim earlier the first treatment. The aim of this study is to estimate the distribution of the period going from the time of first use of cocaine and the time of first contact (latency period) with a Drug Addiction Service and to evaluate the effects of some covariates (such as gender and age at first use of cocaine) on this time lag.