{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,7,30]],"date-time":"2025-07-30T10:04:33Z","timestamp":1753869873191,"version":"3.41.2"},"reference-count":18,"publisher":"Wiley","issue":"2","license":[{"start":{"date-parts":[[2024,1,25]],"date-time":"2024-01-25T00:00:00Z","timestamp":1706140800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100000038","name":"U.S. Food and Drug Administration","doi-asserted-by":"publisher","id":[{"id":"10.13039\/100000038","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100005227","name":"Centers for Medicare and Medicaid Services","doi-asserted-by":"publisher","id":[{"id":"10.13039\/100005227","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100022416","name":"Center for Drug Evaluation and Research","doi-asserted-by":"publisher","id":[{"id":"10.13039\/100022416","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Pharmacoepidemiology and Drug"],"published-print":{"date-parts":[[2024,2]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:sec><jats:title>Purpose<\/jats:title><jats:p>Pharmacy chains can differ with respect to the characteristics of their patient populations as well as their nonprescription products, services, and practices, and thus may serve as a surrogate for potential unmeasured confounding in observational studies of prescription drugs. This study evaluates whether a single\u2010source drug can have different patient outcomes based on the dispensing pharmacy chain.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>Separate analyses for two anticoagulant drugs, rivaroxaban and apixaban, were conducted using Medicare Fee\u2010for\u2010Service claims evaluating the association between dispensing pharmacy chain and outcomes of acute myocardial infarction, ischemic stroke, intracranial hemorrhage, gastrointestinal (GI) bleeding, all\u2010cause mortality, and major GI bleeding. Inverse probability of treatment weighting (IPTW) was used to balance baseline covariates across pharmacy chain cohorts, and outcome association was assessed with a Cox Proportional Hazards model.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>We observed no differences in outcomes across pharmacy chains for apixaban recipients. Rivaroxaban recipients from pharmacy chain C, however, had lower rates of GI bleeding (adjusted HR 0.83; 95% CI 0.69\u20131.00) and ischemic stroke (adjusted HR 0.57; 95% CI 0.38\u20130.87) as compared to chain A in primary analyses with a 3\u2010day grace period. The results moved closer to the null when 14\u2010 and 30\u2010day grace periods were implemented.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusions<\/jats:title><jats:p>These results suggest that dispensing pharmacy chains may have the potential to act as a confounder of associations between drug exposure and outcome in some observational studies. Additional studies of potential confounding by pharmacy chain are needed. Further evaluation of potential pharmacy chain effects on safe use would be of value.<\/jats:p><\/jats:sec>","DOI":"10.1002\/pds.5749","type":"journal-article","created":{"date-parts":[[2024,1,26]],"date-time":"2024-01-26T04:59:46Z","timestamp":1706245186000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Dispensing pharmacy chains and direct anticoagulants: Potential associations with patient outcomes"],"prefix":"10.1002","volume":"33","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7240-3605","authenticated-orcid":false,"given":"Steven","family":"Kozlowski","sequence":"first","affiliation":[{"name":"Center for Drug Evaluation and Research US Food and Drug Administration  Silver Spring Maryland USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ellen","family":"Tworkoski","sequence":"additional","affiliation":[{"name":"Acumen, LLC  Burlingame California USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sai","family":"Dharmarajan","sequence":"additional","affiliation":[{"name":"Center for Drug Evaluation and Research US Food and Drug Administration  Silver Spring Maryland USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Natasha","family":"Flowers","sequence":"additional","affiliation":[{"name":"Acumen, LLC  Burlingame California USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Andrew","family":"Kwist","sequence":"additional","affiliation":[{"name":"Acumen, LLC  Burlingame California USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Shanlai","family":"Shangguan","sequence":"additional","affiliation":[{"name":"Acumen, LLC  Burlingame California USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yoganand","family":"Chillarige","sequence":"additional","affiliation":[{"name":"Acumen, LLC  Burlingame California USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Michael","family":"Wernecke","sequence":"additional","affiliation":[{"name":"Acumen, LLC  Burlingame California USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tom","family":"MaCurdy","sequence":"additional","affiliation":[{"name":"Acumen, LLC  Burlingame California USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jeffrey A.","family":"Kelman","sequence":"additional","affiliation":[{"name":"Centers for Medicare &amp; Medicaid Services  Washington DC USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"David J.","family":"Graham","sequence":"additional","affiliation":[{"name":"Center for Drug Evaluation and Research US Food and Drug Administration  Silver Spring Maryland USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[2024,1,25]]},"reference":[{"doi-asserted-by":"publisher","key":"e_1_2_13_2_1","DOI":"10.5639\/gabij.2019.0803.013"},{"doi-asserted-by":"publisher","key":"e_1_2_13_3_1","DOI":"10.1345\/aph.1P380"},{"issue":"1422","key":"e_1_2_13_4_1","first-page":"31","article-title":"The community pharmacy\u2010based anticoagulation management service achieves a consistently high standard of anticoagulant care","volume":"128","author":"Harper P","year":"2015","journal-title":"N Z Med J"},{"doi-asserted-by":"publisher","key":"e_1_2_13_5_1","DOI":"10.1310\/hpj5203-207"},{"doi-asserted-by":"publisher","key":"e_1_2_13_6_1","DOI":"10.1016\/j.sapharm.2006.11.002"},{"unstructured":"RoeS LongR KingK.Pharmacies miss half of dangerous drug combinations.Chicago Tribune. 2016:11.","key":"e_1_2_13_7_1"},{"unstructured":"GablerE.How chaos at chain pharmacies is putting patients at risk.New York Times. January 31 2020; Health.","key":"e_1_2_13_8_1"},{"doi-asserted-by":"publisher","key":"e_1_2_13_9_1","DOI":"10.1001\/jamainternmed.2016.5954"},{"doi-asserted-by":"publisher","key":"e_1_2_13_10_1","DOI":"10.1002\/sim.3697"},{"doi-asserted-by":"publisher","key":"e_1_2_13_11_1","DOI":"10.1002\/sim.5753"},{"doi-asserted-by":"publisher","key":"e_1_2_13_12_1","DOI":"10.1016\/j.amjmed.2018.12.023"},{"doi-asserted-by":"publisher","key":"e_1_2_13_13_1","DOI":"10.1056\/NEJMp1802313"},{"doi-asserted-by":"publisher","key":"e_1_2_13_14_1","DOI":"10.1002\/sim.7084"},{"doi-asserted-by":"publisher","key":"e_1_2_13_15_1","DOI":"10.1016\/j.jclinepi.2014.03.012"},{"doi-asserted-by":"publisher","key":"e_1_2_13_16_1","DOI":"10.1001\/jamacardio.2016.0199"},{"doi-asserted-by":"publisher","key":"e_1_2_13_17_1","DOI":"10.1136\/bmj.i5549"},{"key":"e_1_2_13_18_1","first-page":"179","article-title":"A randomized direct comparison of the pharmacokinetics and pharmacodynamics of apixaban and rivaroxaban","volume":"6","author":"Frost C","year":"2014","journal-title":"Clin Pharmacol"},{"doi-asserted-by":"publisher","key":"e_1_2_13_19_1","DOI":"10.1016\/j.thromres.2020.10.011"}],"container-title":["Pharmacoepidemiology and Drug Safety"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/pds.5749","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,3,4]],"date-time":"2024-03-04T03:53:37Z","timestamp":1709524417000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1002\/pds.5749"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,1,25]]},"references-count":18,"journal-issue":{"issue":"2","published-print":{"date-parts":[[2024,2]]}},"alternative-id":["10.1002\/pds.5749"],"URL":"https:\/\/doi.org\/10.1002\/pds.5749","archive":["Portico"],"relation":{},"ISSN":["1053-8569","1099-1557"],"issn-type":[{"type":"print","value":"1053-8569"},{"type":"electronic","value":"1099-1557"}],"subject":[],"published":{"date-parts":[[2024,1,25]]},"assertion":[{"value":"2023-01-09","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2023-12-15","order":1,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2024-01-25","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}],"article-number":"e5749"}}