{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,26]],"date-time":"2025-10-26T21:42:52Z","timestamp":1761514972942,"version":"3.37.3"},"reference-count":19,"publisher":"Public Library of Science (PLoS)","issue":"1","license":[{"start":{"date-parts":[[2023,1,4]],"date-time":"2023-01-04T00:00:00Z","timestamp":1672790400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100000009","name":"Foundation for the National Institutes of Health","doi-asserted-by":"publisher","award":["R01AG069733"],"award-info":[{"award-number":["R01AG069733"]}],"id":[{"id":"10.13039\/100000009","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS ONE"],"abstract":"<jats:sec id=\"sec001\">\n<jats:title>Objective<\/jats:title>\n<jats:p>We evaluated whether the Massachusetts COVID-19 vaccine lottery increased vaccine uptake.<\/jats:p>\n<\/jats:sec>\n<jats:sec id=\"sec002\">\n<jats:title>Methods<\/jats:title>\n<jats:p>We analyzed data from the Centers for Disease Control and Prevention COVID-19 Vaccine Tracker to identify total number of adults aged 18 to 64 who received at least first dose of the COVID-19 vaccine or who were fully vaccinated in Massachusetts, Connecticut, Rhode Island, New Jersey, and Vermont during the study period of March 6 \u2013July 31, 2021. Each of the five states contributed 148 days of a daily report on cumulative number of vaccinated people, comprising 740 state-days as the total sample size. We conducted multivariable, state-day level difference-in-differences (DID) regression using a negative binomial regression model that compared the change in outcomes for Massachusetts to those of four geographically adjacent comparison states without the lotteries, before and after the Massachusetts vaccine lottery announcement (June 15, 2021). Our analyses controlled for key state-level characteristics obtained from the American Community Survey as well as day fixed-effects to capture secular trends in the outcomes.<\/jats:p>\n<\/jats:sec>\n<jats:sec id=\"sec003\">\n<jats:title>Results<\/jats:title>\n<jats:p>Massachusetts COVID-19 vaccine lottery was not associated with a significant increase in the number of adults aged 18 to 64 who were fully vaccinated or received at least one dose of the vaccine, compared with other states [Full dose, incidence rate ratio (IRR): 1.04, 95% confidence interval (CI): 0.97 to 1.11, P &gt; 0.05; At least one dose, IRR: 0.99, 95% CI: 0.93 to 1.06, P &gt; 0.05].<\/jats:p>\n<\/jats:sec>\n<jats:sec id=\"sec004\">\n<jats:title>Conclusions<\/jats:title>\n<jats:p>There was insufficient evidence to conclude that Massachusetts COVID-19 vaccine lottery was associated with increased number of adult COVID-19 vaccinations.<\/jats:p>\n<\/jats:sec>","DOI":"10.1371\/journal.pone.0279283","type":"journal-article","created":{"date-parts":[[2023,1,4]],"date-time":"2023-01-04T18:22:32Z","timestamp":1672856552000},"page":"e0279283","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":1,"title":["Did Massachusetts COVID-19 vaccine lottery increase vaccine uptake?"],"prefix":"10.1371","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-0501-6170","authenticated-orcid":true,"given":"Yeunkyung","family":"Kim","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jihye","family":"Kim","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yue","family":"Li","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"340","published-online":{"date-parts":[[2023,1,4]]},"reference":[{"volume-title":"COVID-19 Vaccines Work","year":"2021","author":"Centers for Disease Control and Prevention","key":"pone.0279283.ref001"},{"issue":"20","key":"pone.0279283.ref002","doi-asserted-by":"crossref","first-page":"2043","DOI":"10.1001\/jama.2021.19499","article-title":"Association between mRNA vaccination and COVID-19 hospitalization and disease severity","volume":"326","author":"MW Tenforde","year":"2021","journal-title":"Jama"},{"key":"pone.0279283.ref003","first-page":"71","article-title":"Effectiveness of a Third Dose of mRNA Vaccines Against COVID-19\u2013Associated Emergency Department and Urgent Care Encounters and Hospitalizations Among Adults During Periods of Delta and Omicron Variant Predominance\u2014VISION Network, 10 States, August 2021\u2013January 2022","author":"MG Thompson","year":"2022","journal-title":"MMWR Morbidity and Mortality Weekly Report"},{"volume-title":"Covid: Where and why is the US vaccine rollout slowing down?","year":"2021","author":"BBC","key":"pone.0279283.ref004"},{"volume-title":"Baker announces \u2019VaxMillions\u2019 lottery program, offering $1 million cash prizes to boost vaccination rates","year":"2021","author":"The Boston Globe","key":"pone.0279283.ref005"},{"issue":"8","key":"pone.0279283.ref006","doi-asserted-by":"crossref","first-page":"766","DOI":"10.1001\/jama.2021.11048","article-title":"Lottery-based incentive in Ohio and COVID-19 vaccination rates","volume":"326","author":"AJ Walkey","year":"2021","journal-title":"Jama"},{"issue":"1","key":"pone.0279283.ref007","doi-asserted-by":"crossref","first-page":"78","DOI":"10.1001\/jamainternmed.2021.6170","article-title":"Guaranteed financial incentives for COVID-19 vaccination: a pilot program in North Carolina","volume":"182","author":"CA Wong","year":"2022","journal-title":"JAMA Internal Medicine"},{"volume-title":"COVID-19 Vaccinations in the Unites States, Jurisdiction","year":"2021","author":"Centers for Disease Control and Prevention","key":"pone.0279283.ref008"},{"volume-title":"These are the U.S. states trying lotteries to increase Covid vaccinations","year":"2021","author":"The New York Times","key":"pone.0279283.ref009"},{"issue":"11\u201312","key":"pone.0279283.ref010","doi-asserted-by":"crossref","first-page":"893","DOI":"10.1016\/j.jpubeco.2012.07.004","article-title":"The effect of insurance on emergency room visits: an analysis of the 2006 Massachusetts health reform","volume":"96","author":"S. Miller","year":"2012","journal-title":"Journal of public Economics"},{"volume-title":"FACT SHEET: President Biden to Announce New Actions to Get More Americans Vaccinated and Slow the Spread of the Delta Variant","year":"2021","author":"The White House","key":"pone.0279283.ref011"},{"volume-title":"Governors Start Mandating the COVID-19 Vaccine for State Employees","year":"2021","author":"U.S.News","key":"pone.0279283.ref012"},{"issue":"10","key":"pone.0279283.ref013","first-page":"50","article-title":"The negative binomial regression","volume":"3","author":"S Yang","year":"2015","journal-title":"The Southwest Respiratory and Critical Care Chronicles"},{"key":"pone.0279283.ref014","volume":"16","author":"L. StataCorp","year":"2019","journal-title":"Stata Statistical Software: Release"},{"volume-title":"American Community Survey Data","author":"United States Census Bureau","key":"pone.0279283.ref015"},{"issue":"10","key":"pone.0279283.ref016","doi-asserted-by":"crossref","first-page":"e213117","DOI":"10.1001\/jamahealthforum.2021.3117","article-title":"Association Between Statewide COVID-19 Lottery Announcements and Vaccinations","volume":"2","author":"D Dave","year":"2021","journal-title":"JAMA health forum"},{"issue":"3","key":"pone.0279283.ref017","doi-asserted-by":"crossref","first-page":"677","DOI":"10.1111\/jgs.17619","article-title":"Source of information on COVID\u201019 vaccine and vaccine hesitancy among US Medicare beneficiaries","volume":"70","author":"J Kim","year":"2022","journal-title":"Journal of the American Geriatrics Society"},{"issue":"11","key":"pone.0279283.ref018","doi-asserted-by":"crossref","first-page":"1252","DOI":"10.1016\/j.jclinepi.2011.02.007","article-title":"Simulation-based power calculation for designing interrupted time series analyses of health policy interventions","volume":"64","author":"F Zhang","year":"2011","journal-title":"Journal of clinical epidemiology"},{"issue":"8","key":"pone.0279283.ref019","doi-asserted-by":"crossref","first-page":"11","DOI":"10.1167\/iovs.61.8.11","article-title":"Focus on data: statistical design of experiments and sample size selection using power analysis","volume":"61","author":"J Ledolter","year":"2020","journal-title":"Investigative ophthalmology & visual science"}],"container-title":["PLOS ONE"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0279283","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,1,4]],"date-time":"2023-01-04T18:22:41Z","timestamp":1672856561000},"score":1,"resource":{"primary":{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0279283"}},"subtitle":[],"editor":[{"given":"Jennifer Annette","family":"Campbell","sequence":"first","affiliation":[],"role":[{"role":"editor","vocabulary":"crossref"}]}],"short-title":[],"issued":{"date-parts":[[2023,1,4]]},"references-count":19,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2023,1,4]]}},"URL":"https:\/\/doi.org\/10.1371\/journal.pone.0279283","relation":{},"ISSN":["1932-6203"],"issn-type":[{"type":"electronic","value":"1932-6203"}],"subject":[],"published":{"date-parts":[[2023,1,4]]}}}