Evidence map›Paper›PMID 39618177›Full record

ArticleHealth services research2025

Drivers of infliximab biosimilar uptake: A comparative analysis of new biosimilar initiations versus switching in a national rheumatology registry.

Eric Thomas Roberts, Nick Bansback, Chien-Wen Tseng, Stephen Shiboski, Jing Li, Gabriela Schmajuk, Jinoos Yazdany

Abstract readComparative Study
In one paragraph

Article in Health services research, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.

0numbers the graph read from it
0cells of the map it votes in
3citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

3 citing papers in PubMed.

  1. Article
  2. Article
  3. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

7 authors.

Eric Thomas RobertsDivision of Rheumatology, Department of Medicine, University of California San Francisco, San Francisco, California, USA.ORCID https://orcid.org/0009-0005-8435-8994
Nick BansbackSchool of Population and Public Health, University of British Columbia, Vancouver, British Columbia, Canada.
Chien-Wen TsengDepartment of Family Medicine and Community Health, University of Hawai'i John A. Burns School of Medicine, Honolulu, Hawaii, USA.
Stephen ShiboskiDivision of Rheumatology, Department of Medicine, University of California San Francisco, San Francisco, California, USA.
Jing LiDivision of Rheumatology, Department of Medicine, University of California San Francisco, San Francisco, California, USA.
Gabriela SchmajukDivision of Rheumatology, Department of Medicine, University of California San Francisco, San Francisco, California, USA.ORCID https://orcid.org/0000-0003-2687-5043
Jinoos YazdanyDivision of Rheumatology, Department of Medicine, University of California San Francisco, San Francisco, California, USA.

Funding

RESOURCE-BASED CENTER FOR THE ADVANCEMENT OF PRECISION MEDICINE IN RHEUMATOLOGYP30AR070155 · NIAMS · UNIVERSITY OF CALIFORNIA, SAN FRANCISCO · PI Mary C Nakamura · 2016 to 2026
$8.2M
Advancing Safety Process Innovation in Rheumatology (ASPIRE)R01HS028024 · AHRQ · UNIVERSITY OF CALIFORNIA, SAN FRANCISCO · PI YAZDANY, JINOOS · 2022 to 2025
$1.6M
Advancing Quality and Outcomes Measurement in RheumatologyK24AR074534 · NIAMS · UNIVERSITY OF CALIFORNIA, SAN FRANCISCO · PI Jinoos Yazdany · 2019 to 2026
$1.5M
AHRQ HHS R01 HS028024NIAMS NIH HHS K24 AR074534NIAMS NIH HHS P30 AR070155
6 · The paper itself

Abstract

objectiveTo analyze the variability in new infliximab biosimilar starts as well as switching from bio-originator to biosimilar infliximab, across insurance payers and rheumatology practices nationally. STUDY SETTING AND

designData came from Rheumatology Informatics System for Effectiveness, a national registry with electronic health records from over 1100 US rheumatologists. Key outcomes include ever use of a biosimilar, date of initiation, and date of switching. Key variables of interest include insurance payer and practice. DATA SOURCES AND ANALYTIC SAMPLE: Secondary analysis of 37,560 patients aged ≥18 years administered infliximab (bio-originator or biosimilar) between April 2016 and September 2022 in Rheumatology Informatics System for Effectiveness. We tested for differences in use of biosimilar infliximab by demographic characteristics, socioeconomic status, and diagnosis using standard mean differences and multivariable modified Poisson regression. We used generalized estimating equations to assess the adjusted effect of insurance and year of initiation on new biosimilar starts. We analyzed variation in biosimilar switching by insurance, date of switch, and practice. PRINCIPAL

findingsA total of 8196 (21.8%) infliximab users ever used a biosimilar and use did not differ significantly by demographic or clinical characteristics. In 2022, uptake among new users was higher among those with Medicaid (55%; 95%CI 43%-68%) and private insurance (51%; 95%CI 46%-57%) compared to Medicare (36%; 95%CI 29%-43%). Few prevalent bio-originator infliximab users switched to a biosimilar, and switching was lowest among Medicare beneficiaries (7% vs. 14.2% in Medicaid and 16.9% among privately insured). In adjusted analyses, practice level differences explained 37% of variation among new biosimilar starts and 34% of variation among those switching to a biosimilar.

conclusionsOur findings underscore two critical areas for enhancing biosimilar infliximab usage: increasing switching among prevalent users and increasing uptake among Medicare beneficiaries initiating treatment. Significant variation in uptake across practices also suggests that local switching policies are likely key drivers of uptake.

Indexed as

Antirheumatic AgentsBiosimilar PharmaceuticalsDrug SubstitutionInfliximabAdultAgedFemaleHumansMaleMedicaidMedicareMiddle AgedRegistriesRheumatologyUnited StatesAntirheumatic AgentsBiosimilar PharmaceuticalsInfliximabepidemiologyhealth care financing/Insurance/premiumshealth economicsmedicarepharmaceuticals: prescribing/use/costs

Identifiers

PMID39618177
PMCPMC12120530

What OpenQuestion holds

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.