Existing health survey data of individuals who are 65+ years of age is limited due to the exclusion of the oldest old and physically or cognitively impaired individuals. This study aimed to assess the effects of a sequential mixed-mode design on (1) contact and response rates, (2) sample composition and (3) non-response bias. A register-based random sample of 2,000 individuals 65+ years was initially contacted by mail to answer a health questionnaire. Random subgroups of initial non-responders were further contacted by telephone or home visits. Participation by interview or proxy was possible. After postal contact only, the initial contact and …

Nursing home residents (NHRs) are systematically excluded from the target populations of most population-based health surveys, which may result in biased prevalence estimates. Researchers who wish to include NHRs in surveys face several challenges including difficulty sampling and contacting NHRs and greater levels of functional impairments impeding participation. A population-wide, register-based, random sample of 8,000 older individuals (57.1% women, mean age=76.2 years) in six primary sampling units (PSUs) in Germany was used to analyse NHR coverage. The contact and response rates among NHRs were compared to those among persons living in private households in two PSUs (N=2,000) by applying an …