Determinants of Consent in the SHARE Accelerometer Study

In the eighth wave of the Survey of Health, Ageing and Retirement in Europe (SHARE) a sub-sample of respondents was asked to participate in a measurement of physical activity using thigh-worn accelerometers. This paper describes the consent gaining process, analyses determinants of consent, and investigates whether aggregated results of the accelerometer measurements are biased due to sample selection. Multivariate logit regressions show that various factors are correlated to consent such as the respondents’ age, self-reported moderate activity, self-reported overall health status, memory functioning, computer skills, willingness to answer questions, and the interviewers’ age. Despite these correlations, we do not see a significantly different mean in the average acceleration when applying inverse probability weights, indicating no severe bias in aggregated results of the measurements