{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,26]],"date-time":"2026-09-26T20:47:03Z","timestamp":1790455623504,"version":"4.1.0"},"reference-count":27,"publisher":"Oxford University Press (OUP)","issue":"2","license":[{"start":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T00:00:00Z","timestamp":1759968000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100000049","name":"National Institute on Aging","doi-asserted-by":"publisher","award":["R01AG060975"],"award-info":[{"award-number":["R01AG060975"]}],"id":[{"id":"10.13039\/100000049","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000049","name":"National Institute on Aging","doi-asserted-by":"publisher","award":["R01AG077620"],"award-info":[{"award-number":["R01AG077620"]}],"id":[{"id":"10.13039\/100000049","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,2,5]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>Nursing home (NH) residents are an important population for pharmacoepidemiologic research due to their prevalence of multimorbidity and polypharmacy. Medicare claims are commonly used to study medication use in this population, but medications dispensed during hospitalizations or post-acute care are unobservable due to bundled payment structures. We developed algorithms to identify NH days when medication dispensings can be observed in claims. Using a cohort of NH residents in the United States from 2013 to 2020, we linked Medicare fee-for-service (FFS) claims with Minimum Data Set clinical assessments. NH days were classified as \u201cobservable medication use time\u201d if residents were enrolled in Medicare parts A, B, and D were not receiving post-acute care and were not hospitalized. Among 12.3 million NH residents and 2.7 billion NH days, 1.1 billion days (72.4% of Medicare-enrolled days and 39.6% of all NH days) were identified as observable medication use time. Within the first 100\u00a0days of NH admission, 27.3% of days were medication-observable, increasing to 89.4% after 100\u00a0days. On average, we identified 68% more person-time, and 51% more residents, compared to standard 100-day definitions for \u201clong-stay\u201d NH residents. Our algorithms enhance researchers\u2019 ability to measure medication exposure time, improving the validity of pharmacoepidemiologic studies.<\/jats:p>","DOI":"10.1093\/aje\/kwaf227","type":"journal-article","created":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T12:07:50Z","timestamp":1760011670000},"page":"587-595","source":"Crossref","is-referenced-by-count":5,"title":["Identifying observable medication use time in administrative databases: a tutorial using nursing home residents"],"prefix":"10.1093","volume":"195","author":[{"given":"Daniel A","family":"Harris","sequence":"first","affiliation":[{"name":"Department of Epidemiology, College of Health Sciences, University of Delaware , Newark, DE ,","place":["United States"]},{"name":"Department of Health Services, Policy, and Practice, School of Public Health, Brown University , Providence, RI ,","place":["United 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,","place":["United States"]},{"name":"Center for Gerontology and Healthcare Research,School of Public Health, Brown University , Providence, RI ,","place":["United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sarah D","family":"Berry","sequence":"additional","affiliation":[{"name":"Hinda and Arthur Marcus Institute for Aging Research, Hebrew Senior Life , Boston, MA ,","place":["United States"]},{"name":"Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School , Boston, MA ,","place":["United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5092-9657","authenticated-orcid":false,"given":"Charles E","family":"Leonard","sequence":"additional","affiliation":[{"name":"Department of Biostatistics, Epidemiology, and Informatics, Perelman School of Medicine, University of Pennsylvania , Philadelphia, PA ,","place":["United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yu-Chia","family":"Hsu","sequence":"additional","affiliation":[{"name":"Department of Biostatistics, Epidemiology, and Informatics, Perelman School of Medicine, University of Pennsylvania , Philadelphia, PA ,","place":["United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8474-0310","authenticated-orcid":false,"given":"Douglas","family":"Kiel","sequence":"additional","affiliation":[{"name":"Hinda and Arthur Marcus Institute for Aging Research, Hebrew Senior Life , Boston, MA ,","place":["United States"]},{"name":"Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School , Boston, MA ,","place":["United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1122-0071","authenticated-orcid":false,"given":"Kaleen N","family":"Hayes","sequence":"additional","affiliation":[{"name":"Department of Health Services, Policy, and Practice, School of Public Health, Brown University , Providence, RI ,","place":["United States"]},{"name":"Center for Gerontology and Healthcare Research,School of Public Health, Brown University , Providence, RI ,","place":["United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2196-0134","authenticated-orcid":false,"given":"Melissa","family":"Riester","sequence":"additional","affiliation":[{"name":"Center for Gerontology and Healthcare Research,School of Public Health, Brown University , Providence, RI ,","place":["United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jimmie E","family":"Roberts","sequence":"additional","affiliation":[{"name":"Hinda and Arthur Marcus Institute for Aging Research, Hebrew Senior Life , Boston, MA ,","place":["United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Laura","family":"Reich","sequence":"additional","affiliation":[{"name":"Department of Epidemiology, School of Public Health, Brown University , Providence, RI ,","place":["United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Peyton","family":"Free","sequence":"additional","affiliation":[{"name":"Department of Epidemiology, College of Health Sciences, University of Delaware , Newark, DE ,","place":["United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1673-4570","authenticated-orcid":false,"given":"Andrew R","family":"Zullo","sequence":"additional","affiliation":[{"name":"Department of Health Services, Policy, and Practice, School of Public Health, Brown University , Providence, RI ,","place":["United States"]},{"name":"Center for Gerontology and Healthcare Research,School of Public Health, Brown University , Providence, RI 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