How Different Mixed-Mode Data Collection Approaches Impact Response Rates and Provision of Biomeasure Samples.

Social surveys can be enriched with the collection of objective health measures, allowing new types of research in both health and social sciences. We experimentally tested three alternative designs for collecting survey responses and biomeasures within a longitudinal survey. In the nurse-administered design, a nurse conducts the survey and collects biomeasures in person. In the interviewer-first design, an interviewer initially attempts to carry out the survey in person, collects a subset of biomeasures, and then leaves a further biomeasure sample collection kit with the respondent. The web-first design invites respondents to complete the survey in web mode, and a biomeasure sample collection kit is sent after they do so. Nonrespondents to their initial mode are followed up with in an alternate mode. The outcomes of interest are both (i) response to the survey, and (ii) take-up and completion of the biomeasure sample collection. The impact of the experimental design is tested on both outcomes, utilizing intention-to-treat analysis (that is, by allocated design). To account for the importance of channel of communication in the consent decision for biomeasures, we also analyze observed consent outcomes by realized mode of response, other survey factors, and respondent characteristics. Findings show that the web-first design is superior in obtaining survey response, with nonsignificant differences between in-person interviewer-administered and nurse-administered designs. Conversely, the web was the least effective design for obtaining biomeasures. These findings imply that there is a design trade-off between obtaining survey responses and biomeasures, and this should be considered in future studies.