{"doi":"10.1001/jamanetworkopen.2025.25155","title":"Formulary Restrictions and Relapse Episodes in Persons With Relapsing-Remitting Multiple Sclerosis","abstract":"Importance: Narrow formularies can be used to increase rebates and manage the use of costly drug therapies in the US. Objective: To examine the association between the breadth of formulary coverage for multiple sclerosis (MS) disease-modifying therapies (DMTs) and MS relapse. Design, Setting, and Participants: This retrospective cohort study analyzed 100% Medicare administrative data from 2018 to 2022. The data analysis was conducted from August 1, 2024, to January 30, 2025. Beneficiaries with stand-alone prescription drug plans (PDPs) and Medicare Advantage Prescription Drug plans (MA-PDs) were followed for at least 5 quarters (baseline, quarters 1-4; follow-up, quarter 5). Calendar periods reflected formulary decision-making. Beneficiaries in the same Medicare Part D plan during baseline and follow-up, with relapsing-remitting MS, and with MS DMT use during baseline were included. Exposures: Formulary breadth was low coverage if the 4-quarter moving average of MS DMT drug or class coverage was below the median by plan type and quarter; it was considered high coverage if the average was above the median. Main Outcome and Measures: The primary outcome was MS relapse, including inpatient or outpatient treatment for MS. Multivariable logistic regressions were estimated separately for PDPs and MA-PDs, controlling for patient and plan characteristics and clustering for repeated observations by beneficiary. Results: The claims analysis included 50 162 unique beneficiaries in PDPs (mean [SD] age, 58.5 [12.1] years; 74.9% female) and 34 708 in MA-PDs (mean [SD] age, 58.2 [10.3] years; 77.2% female). Oral or injectable MS DMTs were frequently excluded from coverage (>50% excluded in 2022: PDPs, 11 of 15 DMTs; MA-PD, 9 of 15 DMTs). The MS relapse rate was greater for low- vs high-coverage PDPs (10.6% vs 9.5%; odds ratio [OR], 0.88 [95% CI, 0.84-0.92]) and MA-PDs (7.8% vs 6.9; OR, 0.88 [95% CI, 0.85-0.91]). In multivariable analyses, broader formulary coverage during baseline was associated with less MS relapse during follow-up (PDP: adjusted OR, 0.93 [95% CI, 0.90-0.96] for drugs and 0.94 [95% CI, 0.91-0.97] for classes; MA-PD: adjusted OR, 0.88 [95% CI, 0.83-0.94] for drugs and 0.92 [95% CI, 0.86-0.98] for classes). Conclusions and Relevance: In this cohort study of Medicare data, broader formulary coverage was associated with an 8% to 12% lower odds of MS relapse in MA-PDs and a 6% to 9% lower odds in PDPs. Formulary coverage and restrictions should be tailored for patient need, not just management of costs and use.","journal":"JAMA Network Open","year":2025,"id":524033,"datarank":0.24141568686511508,"base_score":1.6094379124341003,"endowment":1.6094379124341003,"self_citation_contribution":0.24141568686511508,"citation_network_contribution":0.0,"self_endowment_contribution":0.24141568686511508,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":4,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9098,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2025-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":705825,"name":"Karen Van Nuys","orcid":null,"position":1,"is_corresponding":false},{"id":323007,"name":"Geoffrey Joyce","orcid":"0000-0002-6674-0242","position":2,"is_corresponding":false},{"id":1396898,"name":"Barbara Blaylock","orcid":"0000-0002-2063-1796","position":0,"is_corresponding":true}],"reference_count":30,"raw_metadata":{"citation_network_status":"fetched"},"created_at":"2026-07-19T02:50:07.396155Z","pmid":"40748635","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}