Despite their many benefits, longitudinal studies are much less common than one-time data collection or pre-post intervention designs. One reason for their scarcity is that longitudinal studies introduce requirements and challenges that non-longitudinal studies do not. One of the biggest challenges is participant attrition. In order to help…

Mailing campaigns are a way to keep longitudinal survey respondents engaged. While mailings usually include a survey answer request, sometimes respondents are contacted between-waves to update contact information or simply to keep respondent contact. Research on the actual impact of these between-wave contacts on response rates is scarce. This…

Preventing panel members from attriting is a fundamental challenge for panel surveys. Research has shown that response behavior in earlier waves (response or nonresponse) is a good predictor of panelists' response behavior in upcoming waves. However, response behavior can be described in greater detail by considering the time until the response is…

Participant attrition is a significant challenge for longitudinal studies, particularly those involving disadvantaged populations. We attempted to re-engage n = 990 families in a five-year follow-up of a randomised controlled trial of an early childhood parenting intervention. Tracing was attempted for n = 90/990 (9.1%) uncontactable participants.…

This study explored whether the interviewers' judgments of respondents' performances in an initial survey can predict survey participation for a second survey among the same group of respondents in a panel study. Specifically, this study examined two interviewer variables: the interviewers' judgments of (1) the respondents' understanding of survey…

Propensity score weighting often is used to correct for attrition biases in panel surveys. While methodological literature exists on the logic of propensity score weighting and its practical applications, an in-depth discussion is lacking on the effects of using this weighting to correct for attrition biases in attitudinal, behavioral, and…

Attrition represents a significant obstacle to overcome in any longitudinal research project. It is, perhaps, most keenly felt when the data collected are from a qualitative study, since, unlike quantitative longitudinal research, weighting factors cannot be applied to 'correct' for any biases in the achieved sample and even a small number of…

This brief paper introduces a new approach to assessing the trustworthiness of research comparisons when expressed numerically. The 'number needed to disturb' a research finding would be the number of counterfactual values that can be added to the smallest arm of any comparison before the difference or 'effect' size disappears, minus the number of…

Low socio-economic groups are typically difficult to recruit and retain in health research, which makes it difficult to investigate their health-related beliefs and behaviours. Low socio-economic parents with overweight or obese children took part in a longitudinal qualitative child obesity study over 12 months. These parents' views of and…