CONSORT diagram for the Ghana Financial Incentives Trial. Phase I: Treatment.
Phase II/III: This is a two-stage randomized trial in which the treatment regimen is defined such that at least one individual in a treated cluster receives treatment, and, in control clusters, all individuals are allocated to controlBeginning on 13 April 2022, 2 months after the initial intervention, participants were contacted by telephone and asked a short survey including a question about their vaccination status (the survey is available in the Phase III began on 15 June 2022 with two components. In this Reported Vaccination component, enumerators contacted all participants who were not successfully contacted by telephone in phase II of the trial. The 2,019 participants successfully contacted in phase III were asked an identical set of questions to those included in the phase II post-treatment survey.Phase III also entailed an Enumeration of a Sample of Spillover Households consisting of non-treated individuals in treated villages. The spillover sample was drawn from approximately 80 villages in each of the six districts. After enumerators finished surveying each of their recontacted households, they tossed a fair coin to determine whether they would then randomly sample a spillover household. From our treated villages, we obtained a sample of 1,101 non-treated households; these individuals answered the phase III spillover survey (Between 15 October and 30 November 2022, in phase IV, Verified Vaccine Status, the staff of the six District Health Offices were supplied with a list of the 5,900 phase I participants and the 1,101 participants in the spillover sample. The District Health Offices returned a list indicating whether, and when, each of the trial participants had received at least one dose of a COVID-19 vaccine.