In this report, we present the results of a study that aimed to estimate the prevalence of problematic opioid use in Ireland from 2015 to 2019 using a four-source capture-recapture method. Three of the four data sources used for the analysis were derived from opioid substitution treatment records from the Central Treatment List (CTL) (clinics, general practitioners (GPs) and prisons) and the fourth data source was derived from the Probation Service.

Table 1 summarises the main results of this study, stratified by Co Dublin/rest of Ireland as well as by age group and sex. In total, there were an estimated 19,875 problematic opioid users in Ireland in 2019 (95% confidence interval [CI]: 19,522–21,608), which equates to a prevalence rate of 6.68 per 1,000 population (95% CI: 6.57–7.27). The majority of problematic opioid users were male (72.30%) and more than two-thirds (72.93%) of problematic opioid users were in the older 35–64-year-old age group. There were an estimated 11,729 problematic opioid users (95% CI: 11,298–12,944) in Co Dublin in 2019, with a rate over three times higher there than in the rest of Ireland (12.72 per 1,000 population (95% CI: 12.25–14.03) versus 3.97 per 1,000 population (95% CI: 3.84–4.47).

Estimates for prevalence rates in Community Health Organisation (CHO) areas, Regional Drug and Alcohol Task Force (RDATF) areas, regional health areas, and cities are also included in this report.