{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,1,29]],"date-time":"2025-01-29T05:49:42Z","timestamp":1738129782566,"version":"3.33.0"},"reference-count":13,"publisher":"Public Library of Science (PLoS)","issue":"1","license":[{"start":{"date-parts":[[2025,1,28]],"date-time":"2025-01-28T00:00:00Z","timestamp":1738022400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100010269","name":"Wellcome Trust","doi-asserted-by":"publisher","award":["217065\/Z\/19\/Z"],"award-info":[{"award-number":["217065\/Z\/19\/Z"]}],"id":[{"id":"10.13039\/100010269","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100000265","name":"Medical Research Council","doi-asserted-by":"publisher","award":["217065\/Z\/19\/Z"],"award-info":[{"award-number":["217065\/Z\/19\/Z"]}],"id":[{"id":"10.13039\/501100000265","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>Background<\/jats:title>\n<jats:p>Financial incentives may be important for improving response rates to data collection activities and for retaining participants in longitudinal studies. However, for large studies, this introduces significant additional costs. We sought to determine whether an opt-in or an opt-out option for receiving financial incentives when completing questionnaires offers any cost saving measures.<\/jats:p>\n<\/jats:sec>\n<jats:sec id=\"sec002\">\n<jats:title>Methods<\/jats:title>\n<jats:p>The Avon Longitudinal Study of Parents and Children has been ongoing for more than 30 years. It has offered a \u00a310 incentive for returning a partly or fully completed annual questionnaire for &gt;10 years, this is provided by default unless a participant chooses to opt out. For questionnaires completed in 2020 by the original parents recruited to the study and by their offspring, we randomised eligible participants to either opt-out or to opt-in to receiving their vouchers. Logistic regressions determined whether opt-out or opt-in made any difference to the proportion of respondents receiving their vouchers.<\/jats:p>\n<\/jats:sec>\n<jats:sec id=\"sec003\">\n<jats:title>Results<\/jats:title>\n<jats:p>Respondents are less likely to choose to receive a thank you for their time in the form of a \u00a310 shopping voucher if they are asked to opt in compared to if they are asked to opt out. The odds ratio, adjusted for baseline characteristics was 3.94 (95% Confidence Interval: 3.49, 4.45). There was no difference in response rates according to whether respondents were randomised to the opt-in or opt-out group.<\/jats:p>\n<\/jats:sec>\n<jats:sec id=\"sec004\">\n<jats:title>Conclusions<\/jats:title>\n<jats:p>ALSPAC now employs an opt-in procedure for respondents receiving their financial incentive when completing a questionnaire. We recommend similar studies that rely on volunteers consider this option if they want to introduce some cost savings without harming overall response rates.<\/jats:p>\n<\/jats:sec>","DOI":"10.1371\/journal.pone.0316534","type":"journal-article","created":{"date-parts":[[2025,1,28]],"date-time":"2025-01-28T18:31:25Z","timestamp":1738089085000},"page":"e0316534","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":0,"title":["Does opting in or out affect the take up of incentives in a long running population-based cohort study: A nested randomised trial in ALSPAC"],"prefix":"10.1371","volume":"20","author":[{"given":"Kate","family":"Northstone","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Claire","family":"Bowring","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"340","published-online":{"date-parts":[[2025,1,28]]},"reference":[{"key":"pone.0316534.ref001","article-title":"Retention strategies in longitudinal cohort studies: a systematic review and meta-analysis","author":"S Teague","year":"2018","journal-title":"BMC Medical Research Methodology"},{"issue":"4","key":"pone.0316534.ref002","doi-asserted-by":"crossref","first-page":"e0267534","DOI":"10.1371\/journal.pone.0267534","article-title":"The effectiveness of incentives for research participation: A systematic review and meta-analysis of randomized controlled trials","volume":"17","author":"B Abdelazeem","year":"2022","journal-title":"PLOS ONE"},{"key":"pone.0316534.ref003","doi-asserted-by":"crossref","first-page":"249","DOI":"10.1186\/1471-2458-11-249","article-title":"A systematic review of the effect of retention methods in population-based cohort studies","volume":"11","author":"CL Booker","year":"2011","journal-title":"BMC Pub Health"},{"key":"pone.0316534.ref004","volume-title":"Nudge: Improving decisions about health, wealth and happiness","author":"R Sunstein","year":"2008"},{"key":"pone.0316534.ref005","doi-asserted-by":"crossref","first-page":"1338","DOI":"10.1126\/science.1091721","article-title":"Do defaults save live?","volume":"302","author":"EJ Johnson","year":"2003","journal-title":"Science"},{"key":"pone.0316534.ref006","doi-asserted-by":"crossref","first-page":"159","DOI":"10.1017\/bpp.2018.43","article-title":"When and why defaults influence decisions: a meta-analysis of default effects","volume":"3","author":"JM Jackimowicz","year":"2019","journal-title":"Behavioural Public Policy"},{"key":"pone.0316534.ref007","doi-asserted-by":"crossref","first-page":"111","DOI":"10.1093\/ije\/dys064","article-title":"Cohort Profile: The \u2018Children of the 90s\u2019; the index offspring of The Avon Longitudinal Study of Parents and Children (ALSPAC)","volume":"42","author":"A Boyd","year":"2013","journal-title":"International Journal of Epidemiology"},{"key":"pone.0316534.ref008","doi-asserted-by":"crossref","first-page":"97","DOI":"10.1093\/ije\/dys066","article-title":"Cohort Profile: The Avon Longitudinal Study of Parents and Children: ALSPAC mothers cohort","volume":"42","author":"A Fraser","year":"2013","journal-title":"International Journal of Epidemiology"},{"key":"pone.0316534.ref009","doi-asserted-by":"crossref","first-page":"51","DOI":"10.12688\/wellcomeopenres.15132.1","article-title":"The Avon Longitudinal Study of Parents and Children (ALSPAC): an updated on the enrolled sample of index children in 2019","volume":"4","author":"K Northstone","year":"2019","journal-title":"Wellcome Open research"},{"key":"pone.0316534.ref010","doi-asserted-by":"crossref","first-page":"283","DOI":"10.12688\/wellcomeopenres.18564.1","article-title":"The Avon Longitudinal Study of Parents and Children (ALSPAC): a 2022 update on the enrolled sample of mothers and the associated baseline data","volume":"7","author":"D Major-Smith","year":"2022","journal-title":"Wellcome Open research"},{"key":"pone.0316534.ref011","doi-asserted-by":"crossref","first-page":"37","DOI":"10.12688\/wellcomeopenres.18782.1","article-title":"The Avon Longitudinal Study of Parents and children ALSPAC G0 Partners: A cohort profile","volume":"8","author":"K Northstone","year":"2023","journal-title":"Wellcome Open Res"},{"issue":"2","key":"pone.0316534.ref012","doi-asserted-by":"crossref","first-page":"377","DOI":"10.1016\/j.jbi.2008.08.010","article-title":"Research electronic data capture (REDCap)\u2013A metadata-driven methodology and workflow process for providing translational research informatics support","volume":"42","author":"PA Harris","year":"2009","journal-title":"J Biomed Inform"},{"key":"pone.0316534.ref013","volume-title":"Survey methods research on mode and incentives","author":"L Calderwood","year":"2022"}],"container-title":["PLOS ONE"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0316534","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,1,28]],"date-time":"2025-01-28T18:31:32Z","timestamp":1738089092000},"score":1,"resource":{"primary":{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0316534"}},"subtitle":[],"editor":[{"given":"Adnan Ahmad","family":"Khan","sequence":"first","affiliation":[],"role":[{"role":"editor","vocabulary":"crossref"}]}],"short-title":[],"issued":{"date-parts":[[2025,1,28]]},"references-count":13,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2025,1,28]]}},"URL":"https:\/\/doi.org\/10.1371\/journal.pone.0316534","relation":{},"ISSN":["1932-6203"],"issn-type":[{"value":"1932-6203","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,1,28]]}}}