title: Design and protocol of the weight loss lottery- a cluster randomized trial.
abstract: People often intend to exercise but find it difficult to attend their gyms on a regular basis. At times, people seek and accept deadlines with consequences to realize their own goals (i.e. commitment devices). The aim of our cluster randomized controlled trial is to test whether a lottery-based commitment device can promote regular gym attendance. The winners of the lottery always get feedback on the outcome but can only claim their prize if they attended their gyms on a regular basis. In this paper we present the design and baseline characteristics of a three-arm trial which is performed with 163 overweight participants in six in-company fitness centers in the Netherlands.
authors.affiliation: Tilburg University, Tranzo Scientific Center for Care and Welfare, Tilburg School of Social and Behavioral Sciences, PO Box 90153, 5000 LE Tilburg, The Netherlands. Electronic address: k.vdrswaluw@tilburguniversity.edu.
authors.forename: Koen
authors.initials: K
authors.lastname: van der Swaluw
authors.affiliation: National Institute of Public Health and the Environment (RIVM), Department of Quality of Care and Health Economics, Center for Nutrition, Prevention and Health Services, PO Box 1, 3720 BA Bilthoven, The Netherlands.
authors.forename: Mattijs S
authors.initials: MS
authors.lastname: Lambooij
authors.affiliation: Tilburg University, Tranzo Scientific Center for Care and Welfare, Tilburg School of Social and Behavioral Sciences, PO Box 90153, 5000 LE Tilburg, The Netherlands.
authors.forename: Jolanda J P
authors.initials: JJ
authors.lastname: Mathijssen
authors.affiliation: National Institute of Public Health and the Environment (RIVM), Department of Statistics, Informatics and Modelling, Center for Nutrition, Prevention and Health Services, PO Box 1, 3720 BA Bilthoven, The Netherlands.
authors.forename: Maarten
authors.initials: M
authors.lastname: Schipper
authors.affiliation: Tilburg University, Department of Social Psychology, Tilburg School of Social and Behavioral Sciences, PO Box 90153, 5000 LE Tilburg, The Netherlands.
authors.forename: Marcel
authors.initials: M
authors.lastname: Zeelenberg
authors.affiliation: Tilburg University, Tranzo Scientific Center for Care and Welfare, Tilburg School of Social and Behavioral Sciences, PO Box 90153, 5000 LE Tilburg, The Netherlands; National Institute of Public Health and the Environment (RIVM), Department of Quality of Care and Health Economics, Center for Nutrition, Prevention and Health Services, PO Box 1, 3720 BA Bilthoven, The Netherlands.
authors.forename: Johan J
authors.initials: JJ
authors.lastname: Polder
authors.affiliation: Tilburg University, Department of Finance, Tilburg School of Economics and Management, PO Box 90153, 5000 LE Tilburg, The Netherlands.
authors.forename: Henriëtte M
authors.initials: HM
authors.lastname: Prast
mesh_terms: D000328:Adult; D015444:Exercise; D005260:Female; D020446:Fitness Centers; D006801:Humans; D008297:Male; D008875:Middle Aged; D009042:Motivation; D009426:Netherlands; D050177:Overweight / Q000534:rehabilitation*; D015431:Weight Loss; D061217:Weight Reduction Programs
keywords: Cluster randomized trial; Commitment device; Lottery deadline; Physical activity