Supplementary materials for: Response rates in online surveys with participants suffering from neurotic symptoms. A meta-analysis on study design and time effects between 2008 and 2019.

Supplementary materials for: Burgard, T., Bošnjak, M., & Wedderhoff, N. (2020). Response Rates in Online Surveys With Affective Disorder Participants. Zeitschrift für Psychologie, 228(1), 14–24. https://doi.org/10.1027/2151-2604/a000394 A meta-analysis was performed to determine whether response rates to online psychology surveys have decreased over time and the effect of specific design characteristics (contact mode, burden of participation, and incentives) on response rates. The meta-analysis is restricted to samples of adults with depression or general anxiety disorder. Time and study design effects are tested using mixed-effects meta-regressions as implemented in the metafor package in R. The mean response rate of the 20 studies fulfilling our meta-analytic inclusion criteria is approximately 43%. Response rates are lower in more recently conducted surveys and in surveys employing longer questionnaires. Furthermore, we found that personal invitations, for example, via telephone or face-to-face contacts, yielded higher response rates compared to e-mail invitations. As predicted by sensitivity reinforcement theory, no effect of incentives on survey participation in this specific group (scoring high on neuroticism) could be observed. S1: Inclusion and exclusion criteria for study selection; S2: Results from database searches; S4: Descriptive information for each included study; S5: Search strategies unknown