Importance: Antipsychotic agents, such as quetiapine fumarate, are frequently overprescribed for indications not supported by clinical evidence, potentially causing harm.
Objective: To investigate if peer comparison letters targeting high-volume primary care prescribers of quetiapine meaningfully reduce their prescribing.
Design, setting, and participants: Randomized clinical trial (intent to treat) conducted from 2015 to 2017 of prescribers and their patients nationwide in the Medicare program. The trial targeted the 5055 highest-volume primary care prescribers of quetiapine in 2013 and 2014 (approximately 5% of all primary care prescribers of quetiapine).
Interventions: Prescribers were randomized (1:1 ratio) to receive a placebo letter or 3 peer comparison letters stating that their quetiapine prescribing was high relative to their peers and was under review by Medicare.
Main outcomes and measures: The primary outcome was the total quetiapine days supplied by prescribers from the intervention start to 9 months. Secondary outcomes included quetiapine receipt from all prescribers by baseline patients, quetiapine receipt by patients with low-value or guideline-concordant indications for therapy, mortality, and hospital use. In exploratory analyses, the study followed outcomes to 2 years.
Results: Of the 5055 prescribers, 231 (4.6%) were general practitioners, 2428 (48.0%) were in family medicine, and 2396 (47.4%) were in internal medicine; 4155 (82.2%) were male. All were included in the analyses. Over 9 months, the treatment arm supplied 11.1% fewer quetiapine days per prescriber vs the control arm (2456 vs 2864 days; percentage difference, 11.1% fewer days; 95% CI, -13.1% to -9.2% days; P < .001; adjusted difference, -319 days; 95% CI, -374 to -263 days; P < .001), which persisted through 2 years (15.6% fewer days; 95% CI, -18.1% to -13.0%; P < .001). At the patient level, individuals in the treatment arm received 3.9% (95% CI, -5.0% to -2.9%; P < .001) fewer days of quetiapine from all prescribers over 9 months, with a larger decrease among patients with low-value vs guideline-concordant indications (-5.9% [95% CI, -8.0% to -3.9%] vs -2.4% [95% CI, -4.0% to -0.9%], P = .01 for test that effects were equal for both patient groups). There was no evidence of substitution to other antipsychotics, and 9-month mortality and hospital use were similar between the treatment vs control arms.
Conclusions and relevance: Peer comparison letters caused substantial and durable reductions in quetiapine prescribing, with no evidence of negative effects on patients.
Trial registration: ClinicalTrials.gov identifier: NCT02467933.