Advances in Longitudinal Survey Methodology

2Collecting Biomarker Data in Longitudinal Surveys

Meena Kumari and Michaela Benzeval

Institute for Social and Economic Research, University of Essex, Colchester, UK

2.1 Introduction

This chapter provides an overview and summary of methodological issues in collecting biomarker and other biological data in longitudinal surveys. To motivate the chapter, we begin with a discussion of why it is particularly valuable to collect biomarker data together with social and economic information within longitudinal surveys. Biomarkers help us measure different aspects of health earlier and with more precision than survey questions allow, and identify the underlying biological pathways to understand how the ‘social gets under the skin’. We will then focus on methodological issues in biomarker collection where the longitudinal survey context makes a difference. In the main these are similar challenges to those faced by all longitudinal surveys, but with some added complexities caused by the types of measures employed. Key challenges include: consistency and relevance of measures over time and future proofing the study – this is mainly focused on the measures that are taken within data collections but also issues around subsequently storing samples for ‘unknown future use’; possible panel conditioning effects from repeating measures but also from the results of medical tests being fed back to participants; and, the choice of wave, sample and repetition period for biomarker collection to maximise ...