Pairing Professional Norms and Peer Comparison Feedback to Reduce Low-Value Care - Evidence from a Randomized Controlled Trial Among Primary Care Physicians

Q: What intervention was tested to reduce low-value care among primary care physicians?

Eligible physicians received an information letter that paired professional norms with peer comparison feedback about vitamin D testing or generic prescribing. Control physicians received no letter.

Q: How were the primary outcomes measured one year after the intervention?

The paper counts the number of vitamin D tests in 100 patients and the share of generics prescribed to patients one year after the intervention.

Q: Did the intervention also affect generic prescribing rates?

Average generic prescribing was not affected, but heterogeneity analyses show that more than 12% of physicians increased their generic rate by up to 0.88 percentage points.

Sep 16, 2026

Upload by Genevieve

Health care systems invest heavily in low-value care, yet prior strategies to curb it have produced mixed outcomes. This working paper reports a pragmatic randomized controlled trial across Switzerland’s primary care physicians. Practices receiving an information letter combining professional norms and peer comparison feedback about vitamin D testing or generic prescriptions were compared with practices receiving no letter. Outcomes include vitamin D testing rates and generic prescribing one year post-intervention, with causal methods estimating average effects and heterogeneity.

LanguageEnglish

CategoryGeneral

FormatPDF

Pages40

Reading Time14 min

AccessFree to download

Abstract

Introduction

Background and rationale

Intervention concept

Methods

Trial design and participants

Outcomes and endpoints

Estimation strategy

Results

Vitamin D testing impact

Generic prescribing impact

Heterogeneity findings

Conclusions

Key takeaways

Keywords and trial information

Pairing Professional Norms and Peer Comparison Feedback to Reduce Low-Value Care: Evidence from a Randomized Controlled Trial Among Primary Care Physicians Tobias Müller, Ph. D.1 Raf Van Gestel, Ph. D.2 Michael Gerfin, Ph. D.3 WORKING PAPER February 28, 2023 ABSTRACT Background: Health care systems around the globe spend large amounts of money on low-value care. Previous interventions to discourage low-value care practice have delivered mixed results. Methods: We conducted a pragmatic randomized controlled trial involving the universe of Primary Care Physicians (PCPs) in Switzerland. Eligible PCPs in the intervention groups were sent an information letter combining professional norms and peer comparison feedback about vitamin D testing or generic prescriptions. PCPs in the control group received no letter. Primary endpoints were the number of vitamin D tests in 100 patients and the share of generics prescribed to patients one year after the intervention. We estimate average treatment effects (ATEs) based 1 First & corresponding author: Bern University of Applied Sciences, Institute of Health Economics & Policy, Bern (Switzerland), EMail: [tobias.mueller@bfh.ch](tobias.mueller@bfh.ch) 2 Erasmus School of Health Policy and Management & Erasmus School of Economics, Rotterdam (Netherlands), E-Mail: [vangestel@eshpm.eur.nl](vangestel@eshpm.eur.nl) 3 University of Bern, Department of Economics, Bern (Switzerland), E-Mail: michael.gerfin@unibe.ch on multivariate linear regression models and apply the causal forest to assess effect heterogeneity between physician subgroups. Results: n=618 PCPs were randomized to the vitamin D intervention, n=597 to the generic prescribing arm, and another n=601 to the control group. The intervention reduced average vitamin D testing by 18.2%(ATE =-3.66; P<0.001) . The causal forest estimates vary between 1 to 7 tests less in 100 patients (P<0.001). PCPs with high pre-intervention testing levels and older patients show the largest reductions in response to the information letter. Generic prescribing was not affected on average (ATE=+0.56 percentage points; P=0.37), but heterogeneity estimates show that more than 12% of PCPs increased their generic rate by up to +0.88 percentage points (P<0.001). Conclusions: Pairing peer comparison feedback with professional norms can substantially reduce low-value care among PCPs without having unintended consequences. Trial Register Number: AEARCTR-0004747 Keywords: low-value care, overuse, vitamin D testing, generic prescribing INTRODUCTION OECD estimates suggest up to one-fifth of health spending across developed countries is inefficient or wasteful.1 A major concern is that patients often receive medical service with little to no health benefits. Routine lab testing or the prescription of branded drugs with generic equivalents are just two prominent examples of widespread practiced low-value care.2 Estimates for the United States place the costs of unnecessary care somewhere between $75 billion and $100 billion per year.3 The “Choosing Wisely” campaign, launched by the American Board of Internal Medicine Foundation to counter the overtreatment of patients, has recently celebrated its tenth anniversary.4,5 For more than 80 medical disciplines, the platform issues “TOP 5” lists of medical treatments that “physicians and patients should question”. Since its launch, Choosing Wisely campaigns have emerged in more than 25 countries including Canada, the United Kingdom, Germany, Switzerland, and Japan. Despite its public relations success, the publication of “TOP 5” lists does not suffice to systematically change clinical practice and reduce the use of low-value care.6,7 More generally, changing the behavior of healthcare providers has proven to be challenging. Passive strategies such as the dissemination of clinical guidelines or educational materials have repeatedly shown to have limited effects on medical practice.8,9 Active

FAQs

What intervention was tested to reduce low-value care among primary care physicians?

Eligible physicians received an information letter that paired professional norms with peer comparison feedback about vitamin D testing or generic prescribing. Control physicians received no letter.

How were the primary outcomes measured one year after the intervention?

The paper counts the number of vitamin D tests in 100 patients and the share of generics prescribed to patients one year after the intervention.

Did the intervention also affect generic prescribing rates?

Average generic prescribing was not affected, but heterogeneity analyses show that more than 12% of physicians increased their generic rate by up to 0.88 percentage points.

Sep 16, 2026

Upload by Genevieve