Comparing initial and follow-up responders to a New Zealand patient experience survey.

Aim: This study investigates non-response bias in an inpatient experience survey with a low response rate by comparing sociodemographic characteristics and response behaviours of initial responders with responders to follow-up, and further explores the factors contributing to non-response. Prior research suggests non-response may be endogenously related to patient characteristics.
Method: We re-contacted a convenience sample of non-responders to a nationally representative, cross-sectional inpatient survey conducted in New Zealand. Participants were given a subset of six items drawn from the initial survey and the opportunity to disclose reasons for non-response. Responders to follow-up (n=163) were subsequently compared with responders to the initial survey (n=910) using chi-squared tests of association and logistic regression to assess differences in sociodemographic variables and substantive responses.
Results: We find no significant differences in the responses given by initial and follow-up responders. The most common reasons for non-response were "can't remember" (33%), not receiving the survey (25%) or being too busy at the time (25%).
Conclusion: Responders to follow-up have similar experiences of inpatient care in New Zealand to initial responders. Further study is needed to strengthen inferences regarding hard-to-reach patients.
Competing Interests: Nil.