{"doi":"10.1002/hec.4779","title":"Why higher copayments for opioids did not reduce use among Medicare beneficiaries","abstract":"To examine whether higher cost-sharing deterred prescription opioid use. Medicare Part D claims from 2007 to 2016 for a 20% random sample of Medicare enrollees. We obtain estimates of the effect of cost-sharing on prescription opioid use using ordinary least squares and instrumental variables methods. In both, we exploit the variation (change) in cost-sharing within plans over time for a sample of beneficiaries who remain in the same plan. Focusing on changes in cost-sharing within a plan for a constant sample of beneficiaries mitigates potential bias from plan selection and using a constant set of weights derived from use in year (t) eliminates changes in the cost-sharing indexes due to (endogenous) consumer choice in year (t+1). Part D plans adopted benefit changes designed to reduce opioid use, including moving opioids to higher cost-sharing tiers. Increasing plan copayments for hydrocodone or oxycodone was associated with reductions in plan-paid claims and offsetting increases in cash claims. Widespread availability of low-cost generics combined with the anti-clawback provision in Part D mediated the effect of higher cost sharing to curb opioid use. As plans moved generic opioids to higher cost-sharing tiers, beneficiaries simply paid cash prices and aggregate use remained largely unchanged. The anti-clawback provision in Part D, intended to protect beneficiaries from price gouging, limited plans' ability to constrain opioid use through typical demand-side measures such as increased cost-sharing.","journal":"Health Economics","year":2023,"id":414187,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":0,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9083,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2023-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":946142,"name":"Bo Zhou","orcid":"0000-0001-9440-6295","position":1,"is_corresponding":false},{"id":379261,"name":"Robert Kaestner","orcid":"0000-0002-5196-8690","position":2,"is_corresponding":false},{"id":323007,"name":"Geoffrey Joyce","orcid":"0000-0002-6674-0242","position":0,"is_corresponding":true}],"reference_count":26,"raw_metadata":null,"created_at":"2026-07-19T01:22:01.321790Z","pmid":"37985466","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":[]}