An estimation of the prevalence of opioid dependence in New Zealand.

BACKGROUND: An accurate prevalence estimate for opioid dependence in New Zealand, and hence the extent of unmet treatment need, is lacking. METHODS: Opioid users were recruited via snowball sampling, with participants initially recruited from opioid substitution treatment (OST) services and dedicated needle exchanges in Auckland, Tauranga and Christchurch. Participants estimated the number of people they knew personally who were receiving OST and who were not receiving OST, but were using opioids daily or almost daily. From these estimates a multiplier of the ratio between these two groups was derived and applied to the known number receiving OST in New Zealand to arrive at the total population estimate. RESULTS: The mean multiplier estimate, weighted for treatment site, for 84 recruited participants was 2.015. The multiplier was higher for Christchurch. Initial recruitment source did not influence the value of the multiplier estimate. When the multiplier was applied to the known size of the New Zealand OST treatment population the total opioid dependent population was estimated to be 9142 (95% CI: 8248-10036), of whom half were not receiving OST. CONCLUSION: This figure was lower than for previous less robust estimates, but still represents a substantial level of unmet need. Greater effort needs to be made to close this treatment gap.

Consumer and treatment provider perspectives on reducing barriers to opioid substitution treatment and improving treatment attractiveness.

In New Zealand approximately 4600 people receive opioid substitution treatment (OST) for opioid dependence, primarily methadone maintenance treatment. This study explored ways in which OST could be improved, given the significant waiting times for treatment. Two parallel surveys were conducted: 1) peer interviews with 85 regular daily or almost daily opioid drug users (51.8% receiving OST, 18.8% not currently receiving OST, and 29.4% never received OST) and; 2) a census of all 18 specialist OST service providers. When asked how OST might be improved, the four categories most commonly cited by the opioid users were 'better treatment by staff', 'more flexibility', 'better takeaway arrangements', and 'decreased waiting time'. Both opioid users and specialist services rated 'restricted takeaways' and 'having to go on a waiting list' in the top three perceived barriers to OST. Almost all services reported significant resource issues and barriers to the transfer of stable clients from specialist services to continuing treatment in primary care. The findings from this study indicate how OST can be made more accessible and attractive and thus achieve better uptake and retention.