All time references are in CEST
Maintaining contact and tracking participants in longitudinal studies |
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| Session Organisers | Mr Matt Brown (Centre for Longitudinal Studies, UCL) Ms Carole Sanchez (Centre for Longitudinal Studies, UCL) Ms Lucy Haselden (Centre for Longitudinal Studies, UCL) |
| Time | Tuesday 18 July, 09:00 - 10:30 |
| Room | |
Longitudinal surveys are invaluable for tracking changes over time and understanding long-term trends, but keeping in touch with participants, maintaining their engagement and locating them when they move are all significant challenges. Losing touch with participants is a major cause of attrition. Those running longitudinal studies typically use a mix of approaches to maintain contact. These include “prospective approaches”, used to ensure that contact details are kept up to date in order to minimise the risk of losing touch in the first place, and “retrospective approaches”, used to locate participants when they are found to have moved. Evidence from some studies suggests that increasing concerns about data privacy has reduced the effectiveness of some of the techniques which have typically been used in longitudinal studies to maintain contact and track participants– for example, study members may be less willing to provide contact details for an alternative contact (e.g. a relative or friend) and opting out from contact details being available in telephone directories or other databases (e.g. the electoral role) is increasingly common.
This session provides an opportunity to discuss this challenge and share information about approaches used in longitudinal studies to keep in touch with participants between waves, to ensure contact details held are kept up to date and to track those who have moved.
We invite submissions which describe different approaches used to maintain contact with longitudinal study participants in between waves and to track those who have moved. We welcome submissions which describe new innovative approaches – for example, use of: internet/social media, administrative data, commercial databases, new software and particularly encourage submissions which evaluate the success of different approaches.
Keywords: Longitudinal studies, Panel surveys, Cohort studies, Tracking, Tracing, Engagement
Dr Oliver Lipps (FORS)
Dr Marieke Voorpostel (FORS) - Presenting Author
To maintain sample size and representativeness in household panel surveys, it is essential that household reference persons provide contact details of household members that left the household, and subsequently that these household members continue their participation and introduce new households in the sample. As more household panel surveys transition from interviewer-based modes to web-based modes, a key unanswered question is whether web-based surveys are equally successful as interviewer-based modes in maintaining cooperation of household members who left the household. Without the assistance of an interviewer—who typically provides motivation and social control—there is a risk of significant underreporting of moved household members in the web mode.
In this paper, we compare the telephone and web modes using data from a mode experiment and a refreshment sample of a probability sample household panel survey. The experiment shows no significant difference between the modes, suggesting no mode effects. While this is reassuring, the refreshment sample, where households are assigned to modes based on the availability of a telephone number, reveals that although households in the web group contain more mobile sample members, household reference persons in the web group are less likely to report new addresses. This is an issue that should be taken into account when the shift to web is made. More research is needed to find an optimal balance between ease of mode assignment and adequate reporting of moved household members.
Ms Orlaith Tunney (NIDI-KNAW) - Presenting Author
A key issue for longitudinal social surveys is participant attrition. Keeping contact between the participant and the research organization is a crucial aspect of panel maintenance. However, finding effective and efficient ways of maintaining contact with participants remains a challenge for researchers. The Gender and Generations and Gender Survey (GGS), a large-scale cross-national survey investigating life-course and family dynamics, is uniquely placed to provide useful insights into various contact strategies used across cultures and contexts.
To date, over twenty countries have fielded at least one wave of the GGS (GGS-II) with four countries having fielded two waves. The use of panel maintenance strategies in the GGS is highly encouraged by the central coordination team of the Gender and Generations Programme (GGP-CCT). However, given that factors such as social norms, as well as budgetary and legal constraints may vary greatly between countries, the type of strategies employed - as well as their execution - is left up to individual GGS country teams. Consequently, the extent to which GGS countries engage with participants between survey waves differs significantly. Therefore, the GGS can provide excellent insights into the use of various contact strategies cross-nationally, as well as their pitfalls and opportunities.
This presentation will outline the various approaches and strategies used by GGS country teams to maintain continued contact with participants, and the efficacy of these approaches. It will further discuss the reflections and feedback of the country teams themselves on implementing these approaches. In providing lessons learned from the GGS, this presentation gives insights into innovative methods of engaging with participants as part of longitudinal research, as well as practical information for researchers on reducing panel attrition.
Dr Noura Insolera (University of Michigan, Institute for Social Research) - Presenting Author
The Panel Study of Income Dynamics (PSID) is a longitudinal study of a nationally representative sample of U.S. families. Begun in 1968, the study was fielded annually until 1997, and biennially thereafter. Since the beginning of the study, families have been offered a modest incentive in exchange for returning a postcard via U.S. postal mail on which they verify or update their contact information (addresses, phone numbers, email addresses) with the goal of keeping track of their whereabouts between waves of data collection. Having updated contact information prior to data collection is associated with lower fieldwork effort and refusal conversion efforts, less tracking, and lower attrition. Response to the contact update also signals the intent to complete an interview in the next wave. In 2022 an effort was made to redesign the between-wave mail-based contact strategy used for many decades to include multiple modes (mail/web) with the goals of improving participation and reducing costs. In advance of the 2023 and 2025 waves, over 12,500 families were sent a mailing and could choose to either return the information via postal mail or provide an update on the web. To respond by web, respondents were first instructed to scan a quick response (QR) code printed on the postcard. These QR codes contained secure, authenticated links to a prefilled contact information listing for their family. In addition, email reminders were sent to respondents who previously provided an email address. The 2024 mixed mode response rate exceeded the prior waves by over 14% with a shorter field period. This presentation describes the mixed mode contact update design and protocol, its response rate, and socio-demographic characteristics of participating families compared to the traditional mailing (1969-2020) and initial mixed mode effort used in the prior wave (2022).
Ms Eva Leissou (University of Michigan, Survey Research Center) - Presenting Author
Mr Paul Burton (University of Michigan, Survey Research Center)
Mr Derek Dubuque (University of Michigan, Survey Research Center)
Panel attrition is a growing problem for longitudinal studies, either because of panel respondents’ reluctance to participate or because they are difficult to locate during subsequent waves. The Health and Retirement Study (HRS) has experienced attrition due to both factors, with the percent of sample lost in locating increasing from 4% in 2018 to 7% in 2022.
To maximize sample retention, HRS has been employing various design features and fieldwork procedures. Some prospective panel maintenance protocols are maintaining an address update database, mailing newsletters between waves of data collection, and asking participants to provide up to two contact persons (CPs) after completing their interview. Significant time and effort is also spent on contacting and locating participants. Field interviewers are best suited for in-person locating efforts, and a centralized locating team focuses on online searches.
This study reviews these HRS panel maintenance protocols and evaluates their effectiveness. Although the rate of obtaining CP information has declined across waves, when CP information is available the rate of participation increases significantly. In 2018, panel members who provided at least 1 CP after their 2016 interview had 18.5 percentage points higher response rate (RR) than those who had not provided any CPs. An even bigger difference in RR between these groups was observed in 2020 (25.3 percentage points), and in 2022 (28.5 percentage points). Having CP information has also increased the success of locating efforts.
Over the waves, we have seen a decline in locating leads found through online and database searches. In 2016, leads found through database and online searches resulted in a 45% locating rate, while in 2022 the rate dropped to 31.4%.
These results emphasize the importance of continuing to request CP information from participants, and of understanding what drives participants to provide CP information.