Example B: Using online respondent-driven sampling among Moroccan immigrants in the Netherlands

Abstract

Abstract The Dutch Health Council recommended chronic hepatitis B (HBV) screening for first-generation immigrants originating from intermediate/high HBV endemic countries. The Council proposed two screening strategies; individual case finding by general practitioners and local screening programmes. Our aim was to explore knowledge and information needs regarding chronic HBV and its screening among Moroccan immigrants in the Netherlands, in order to provide Dutch Municipal Health Services insights on how to inform immigrants. We also studied a randomized recruitment method using respondent-driven sampling (RDS) for a better understanding on how to reach and recruit immigrants for an online questionnaire. First- and second-generation Moroccan immigrants were asked to fill in an online questionnaire and forward this to four Moroccan contacts. Participants were randomized to one of three recruitment strategies; no incentive for filling in the questionnaire nor for successfully recruiting each contact, an incentive for filling in the questionnaire and for successfully recruiting each contact, and a gamified element as non-monetary incentive to stimulate peer-recruitment. Preliminary analyses show a sample of 59 Moroccans (17-59 years), of which 63% was second-generation and 76% was female. Of these, 46% would like to have information about chronic hepatitis B, while the average knowledge score was 5.02 (0-10). Over 60% of the participants intends to participate in chronic HBV screening, and would also recommend this to their (grand)parents. Using a monetary incentive seemed to be the best recruitment strategy in terms of the number of waves (max: 3). A gamified non-monetary incentive was least effective in stimulating peer-recruitment (max: 0). Despite the limited level of knowledge and information need, the majority of Moroccan immigrants had a positive screening intention. The next step is to determine whether our methodology could be applied to reach other immigrant groups.