A 2023 article by Durand et al.1 examined the impact of changes introduced to the delivery of opioid agonist treatment (OAT) on the number of people accessing treatment and treatment dropout during the Covid-19 pandemic. This is an important Irish study, as it directly examines OAT coverage and access during the pandemic.

Background

Prevalence of opioid usage and access to OAT

Opioid use disorder (OUD) represents a significant public health challenge. Globally, it is estimated that 40.5 million people are dependent on opioids, while current Irish figures suggest that 6.18 per 1,000 population aged 15–64 years are using opioids.2,3 In Ireland, methadone is the most-used OAT, with buprenorphine added to the list of approved treatments for OUD in 2017. The Central Treatment List (CTL) is the national treatment register for OAT in Ireland.

Potential impact of pandemic on service use and delivery

With the advent of the Covid-19 pandemic and the implementation of widespread public health measures, access to a variety of health services and health-service delivery were affected. This led to concerns about the potential implications of these Covid-controlling measures on OAT delivery. OAT in Ireland is based on face-to-face contact, which coupled with treatment interruptions, changes to drug availability, and the price and potency of illicit drugs had the potential to increase drug-related harms, including overdose.4,5 In response to these challenges, rapid access and/or low-threshold pathways were developed as part of the national contingency guidelines by the Health Service Executive (HSE) in March 2020.

These pathways helped to ensure rapid access and uninterrupted care to those on OAT and new users, mitigating the risk of drug-related harms. E-consultations, electronic prescriptions, and home delivery of medication for those isolating were also some of the measures introduced to further enable continuity of OAT.

Methods

Using interrupted time series (ITS) analyses, monthly CTL data from March 2019 to February 2020 were compared against April 2020 to March 2021. ITS support the collection of anonymised aggregate-level data over consistent periods of time, which in this case allowed for the primary outcomes to be assessed appropriately. The primary outcomes for the study were calculating the total amount of service users, the total number of new service users, and the number of those that dropped out.

Results

In March 2019, a total number of 10,251 service users accessed OAT, featuring: female (30%); male (70%); 44% aged under 40 years; 98% prescribed methadone; 2% prescribed buprenorphine. In March 2021, a total number of 11,441 service users were recorded, featuring: female (29%); male (61%); 49% aged under 40 years; 96% prescribed methadone; 4% prescribed buprenorphine. Analyses displayed an increase in those accessing OAT on the last day of the month between April 2020 to March 2021 compared with March 2019 to February 2020. The study observed a significant immediate and continued increase in people accessing OAT following the introduction of OAT contingency guidelines. Changes in treatment initiation or dropout during these time periods were found not to be significant. However, the rate of dropout of those on buprenorphine was found to be reduced.

Discussion

This study suggests that changes to OAT under the national contingency guidelines had a positive impact on coverage in Ireland, which represents an important protective factor for reducing drug-related harm, including mortality.6 The study showed that the highest number of service users commenced or recommenced treatment in April 2020. The authors suggest that this can be attributed to a backlog of people on the waiting list, which, once addressed, led to reduced numbers in the following months. The contingency guidelines for OAT recommended multiple changes to the delivery of OAT. Which specific changes or combination of changes that led to these observed effects are unknown.

The rate of OAT dropout was lowest in April 2020 and January 2021, corresponding to ‘hard’ lockdown measures in Ireland (i.e. closure of all non-essential retail, restriction of movement, police enforcement), which is consistent with published literature on this period.

The limitations of this study include the delays in updating the CTL with exit details for service users. Such information bias could lead to underestimates (delayed reporting) or overestimates (misclassification of deaths as dropouts) of the number of dropouts, and the lack of clarity on which changes to OAT delivery were associated with increased access/uptake. However, the study provides valuable insights into the effect that the HSE contingency guidelines had on OAT service uptake and access.

Conclusion

The findings of the study suggest the OAT contingency guidelines developed during the pandemic increased access to OAT in Ireland. However, it is not yet known if these positive changes were sustained following the easing of pandemic restriction measures.

1    Durand L, Boland F, Harnedy N, et al. (2023) Impact of changes to the delivery of opioid agonist treatment, introduced during the COVID-19 pandemic, on treatment access and dropout in Ireland: an interrupted time series analysis. J Subst Use Addict Treat, 149: 209029. Available from: https://www.drugsandalcohol.ie/38527/

2    Degenhardt L, Grebely J, Stone J, et al. (2019) Global patterns of opioid use and dependence: harms to populations, interventions, and future action. Lancet, 394(10208): 1560–1579.

3    Millar S (2018) New estimates of problem opiate use in Ireland. Drugnet Ireland, 64 (Winter): 1–3. Available from: https://www.drugsandalcohol.ie/28566/

4    Marsden J, Darke S, Hall W, et al. (2020) Mitigating and learning from the impact of COVID-19 infection on addictive disorders. Addiction, 115(6): 1007–1010. Available from: https://www.drugsandalcohol.ie/31834/

5    Volkow ND (2020) Collision of the COVID-19 and addiction epidemics. Ann Intern Med, 173(1): 61–62. Available from: https://www.drugsandalcohol.ie/32301/

6    Santo T Jr, Clark B, Hickman M, et al. (2021) Association of opioid agonist treatment with all-cause mortality and specific causes of death among people with opioid dependence: a systematic review and meta-analysis. JAMA Psychiatry, 78(9): 979–993. Available from: https://www.drugsandalcohol.ie/34301/