For a study, researchers sought to determine if higher opioid agonist therapy (OAT) take-home dosages early in the COVID-19 epidemic were related to treatment retention and opioid-related harm. A retrospective propensity-weighted cohort analysis of 21,297 patients in Ontario, Canada, who were actively getting OAT on March 21, 2020. Changes in OAT take-home dosage frequency were evaluated between March 22, 2020, and April 21, 2020, and people were followed for up to 180 days to assess results (last date of follow-up, October 18, 2020). Exposure was defined as extended take-home doses within each of four groups depending on OAT type and baseline take-home dosage frequency (daily dispensed methadone, 5-6 take-home doses of methadone, daily dispensed buprenorphine/naloxone, and 5-6 take-home doses of buprenorphine/naloxone).
The median age of the 16, 862 methadone and 4,435 buprenorphine/naloxone patients was 38 to 42 years, and 29.1% to 38.2% were female. Among those receiving daily dispensed methadone (n=5,852), starting take-home doses was associated with lower risks of opioid overdose (6.9% vs 9.5% /person-year; weighted hazard ratio [HR], 0.73 [95% CI, 0.56-0.96]), treatment discontinuation (51.0% vs 63.6% /person-year; weighted HR, 0.80 [95% CI, 0.72-0.90]), There was no significant difference in any outcomes across exposure groups among patients taking daily administered buprenorphine/naloxone (n=662). Extended take-home methadone doses were associated with lower risks of OAT discontinuation (14.1% vs 19.6% /person-year; weighted HR, 0.72 [95% CI, 0.62-0.84]) and interruption in therapy (5.1% vs 7.4% /person-year; weighted HR, 0.69 [95% CI, 0.53-0.90]), and extended take-home buprenorphine doses were significantly associated with lower risks of interruption in therapy (9.5% vs 12.9%/person-year; weighted HR, 0.74 [95% CI, 0.56-0.99]) compared with no change in take-home doses. There were no significant differences in the other key outcomes between the groups.
During the COVID-19 pandemic in Ontario, Canada increased take-home doses of opioid agonist therapy were significantly associated with lower rates of treatment interruption and discontinuation among some subsets of patients receiving opioid agonist therapy, and there were no statistically significant increases in opioid-related overdoses over a 6-month follow-up period. These findings might be influenced by residual confounding and should be treated with caution.