Hidden aspects of the opioid crisis: what factors are driving ageing trends among those using opioid drugs?

Background and aim: Scientific literature has identified older people who use opioids as an under researched population. Little is known about the typology of opioid using behaviours or about treatment demand among this ageing population. The aim of this study was to utilise national epidemiological treatment data to determine if certain types of opioid users are driving ageing trends.

Design: Cross-sectional study

Setting: Ireland

Participants: A total of 7,933 new individuals entering treatment for opioid use between 2009 and 2015.

Measurements: This study utilises data on new opioid treatment admissions within the European Treatment Demand Indicator (TDI) for Ireland to conduct a cluster analysis for homogenous groups.

Findings: A TwoStep cluster analysis identified five distinct profiles

Cluster 1: over-the-counter/prescription/other opioids use and late-onset drug use (n=864, 10.9%). Cluster 2: heroin use and the shortest duration between opioid onset and treatment (n=1,594, 20.1%). Cluster 3: heroin use and late-onset opioid use (n=1,123, 14.2%). Cluster 4: heroin use and young treatment entrants (n=1,766, 22.3%). Cluster 5: heroin use, young treatment entrants with early-opioid onset and long durations between opioid onset and treatment (n=2,586, 32.6%). Groups were characterised by type of opioid used, age of opioid onset, age entering treatment, duration between first opioid use and treatment entry. Significant differences were detected in gender (Z=329.78, p<0.001), age (U=1033.81, p<0.001), employment status (Z=504.021, p<0.001), living accommodation (Z=335.85, p<0.001) and arrangements (Z=839.287, p<0.001), school leaving age (U=299.01, p<0.001), level of educational attainment (Z=672.591, p<0.001) and geographical location (Z=49.911, p<0.001). Important temporal changes were detected including: (1) a significant increase in the median age entering treatment (p<0.001) within clusters three, four and five, and (2) a significant increase in opioid using durations prior to seeking treatment within clusters four and five (p<0.001).

Conclusions: This is the first study to undertake an in-depth analysis of ageing, the onset of opioid use and duration of use prior to treatment entry, utilising national case level treatment data over a prolonged period. Not only are people admitted for opioid use treatment ageing, several hidden groups exist, and only certain groups contribute to the ageing trends. The study findings can assist services to prepare for the future challenges posed by ageing opioid users.