Effect of Peer Comparison Letters for High-Volume Primary Care Prescribers of Quetiapine in Older and Disabled Adults: A Randomized Clinical Trial

Abstract

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.

Conflict of interest statement

Conflict of Interest Disclosures: None reported.

Figures

Figure 1.. CONSORT Flow Diagram of Prescribers in the Study

CMS indicates Centers for Medicare & Medicaid Services; CONSORT, Consolidated Standards of Reporting Trials. aReproductions of letters can be found in Supplement 1.

Figure 2.. Quarterly Average Quetiapine Prescribing in Control and Treatment Arms

A, Counts all days supplied by the prescribers. B, Counts only days supplied for new patient starts. Each point represents the average number of quetiapine days supplied in each quarter per prescriber relative to the intervention start date. Error bars indicate 95% CIs. Arrowheads denote when letters were sent to prescribers.

Figure 3.. Cumulative Effect on the Receipt of Quetiapine by Low-Value and Guideline-Concordant Patients Over 9 Months

In each panel, the left-most bar shows the percentage difference in quetiapine days between control and treatment patients from all prescribers in the 9 months after the start of the intervention. The next 3 bars display percentage point contributions to the percentage difference of the following 3 mutually exclusive categories: the patient’s study prescriber, other nonpsychiatric prescribers, and other psychiatric prescribers. The contributions of these 3 categories sum to the all prescriber percentage difference. Each bar reports an adjusted percentage difference (difference between control and treatment means, divided by the control mean; difference adjusted for baseline receipt and other characteristics described in the Statistical Analysis subsection of the Methods section and the Regression Control Variables subsection of the Statistical Approach section of Supplement 1). Error bars indicate 95% CIs. See eTable 3 in Supplement 2 for coefficients.