When evaluating a medication, researchers sometimes overlook a key factor: retention.
But how meaningful are other data, if patients drop out of treatment?
A study recently published in JAMA Letters used U.S. prescription data to evaluate recent trends in buprenorphine initiation and retention. A team of researchers led by Kao-Ping Chua, MD, PhD, of the University of Michigan Medical School, conducted the study.
Earlier studies had examined initiation and retention rates for buprenorphine through 2020, so the time was right for a reassessment, using data from January 2016 through October 2022, the JAMA authors reasoned. They noted that buprenorphine access had improved since 2020, for two reasons:
• Training requirements for buprenorphine waivers were eliminated in April 2021
• Social distancing measures related to COVID-19 were relaxed, lowering barriers to patients who were visiting medical offices; this in turn would be expected to increase opportunities for diagnosing and treating opioid use disorder (OUD)
Database: The investigators used the IQVIA Longitudinal Prescription Database (an all-payer database that reports 92% of the prescriptions dispensed by retail pharmacies in the U.S.)
Buprenorphine prescriptions: initially these included prescriptions dispensed during the study period to patients in the U.S. or the District of Columbia; excluded were prescriptions with missing or potentially invalid data
Buprenorphine products: included were immediate-release and extended-release formulations approved for OUD, but not formulations used primarily to treat pain
The investigators calculated the monthly buprenorphine initiation rate, defining it as the number of patients per 100,000 starting buprenorphine treatment. They also calculated the monthly proportion of initiates retained in treatment.
During January 2016 through October 2022, the monthly buprenorphine initiation rate increased, then flattened. This flattening occurred before the COVID-19 pandemic, suggesting that factors other than the pandemic were involved. Throughout the study period, including in 2021- 2022, only one in five patients who began taking buprenorphine were retained in treatment for at least 180 days. This rate was similar tothat found in a prior study that examined data through the end of 2020.
Retention analyses were stopped in April 2022 so that a 180-day look-forward period could be observed.
(See the complete study for definitions and statistical details.)
Initially included 94,106,548
Monthly initiation rate during the study period: 3,006,629. The monthly initiation rate increased from October 2018, then flattened through October 2022. For the study period, January 2016 through April 2022: median monthly retention rate was 22.2%.
During the study period, 3,006,629 patients began taking buprenorphine. Only one in five patients who started taking buprenorphine stayed in treatment for at least 180 days.
|Retention: defined in the study as 180 or more days of continuous buprenorphine treatment, after the initial dispensing date; no gaps exceed seven days (the definition is based on rationale from the National Quality Forum). The NQF notes: Across all the medications, the mortality risk is highest in the first four weeks out of treatment, with many studies showing an increase in mortality in days 1-14 after treatment cessation.
Only one in five patients who were started on buprenorphine
were still in treatment 180 days later.
In closing, the authors note the need for a comprehensive effort to make buprenorphine more available to patients:
“These findings suggest that recent clinical and policy efforts to increase buprenorphine use have been insufficient to meet the needs for this medication. A comprehensive approach is needed to eliminate barriers to buprenorphine initiation and retention, such as stigma and uneven access to prescribers.”
To summarize: this study shows that retention data are all-important when evaluating medications for treating OUD. To state the obvious: once patients drop out, treatment ends.
Chua KP, Nguyen TD, Zhang J, Conti RM, Lagisetty P, Bohnert AS. Trends in Buprenorphine Initiation and Retention in the United States, 2016-2022. JAMA. 2023;329(16):1402-1404. doi:10.1001/jama.2023.1207
For Additional Reading
Nordstrom B. Good intentions alone won’t solve the country’s opioid crisis. The Hill. May 16, 2023. https://thehill.com/opinion/healthcare/4004930-good-intentions-alone-wont-solve-the-countrys-opioid-crisis/
Four out of five buprenorphine patients drop out: Study. Alcoholism & Drug Abuse Weekly. May 1, 2023.