Grønkjær M S, Elsborg P, Lau C J, Bekker-Jeppesen M, Gøtzsche N, Jacobsen M H, Andreasen A H, Eliasen M H
Center for Clinical Research and Prevention, Copenhagen University Hospital - Bispebjerg and Frederiksberg, Copenhagen, Denmark.
Nordea Pension, Copenhagen, Denmark.
BMC Med Res Methodol. 2025 May 3;25(1):119. doi: 10.1186/s12874-025-02578-2.
Choice of survey administration features in surveys mapping population health may influence the participation and the generalizability of the results. This randomized study aimed to investigate whether three digital letters (denoted single-mode administration) lead to similar participation as two digital and three physical letters mailed with shorter duration between reminders (denoted sequential mixed-mode administration).
In total, 9,489 individuals who participated in The Danish Capital Region Health Survey in 2017 were randomized to re-invitation in 2021 (≥ 20 years) by either single-mode with three digital letters (N = 4,745) or sequential mixed-mode survey administration with two digital and then three physical letters (N = 4,744). To investigate the influence of survey administration on representativeness, the two groups were compared regarding sociodemographic characteristics of participants (age, sex, country of origin, education, labor market attachment). Generalized linear models were used to estimate absolute and relative differences between the two administration groups in participation rates (overall and the increase after reminders). It was also investigated whether sociodemographic factors moderated the association between administration group and participation.
At the end of follow-up, the participation rate was significantly higher in the sequential mixed-mode group, which received five letters (78%), than in the single-mode group, which received three letters (61%), primarily due to a greater increase in participation after switching to physical administration and an increase after the two additional reminders in the mixed-mode group. Overall, individuals who decided to participate in the two groups were comparable in all sociodemographic factors, yet older participants appeared to benefit more from switching to physical administration and younger participants from additional reminders.
Depending on the target population, sequential mixed-mode survey administration and/or multiple reminders could be considered to increase participation; however, it does not necessarily improve the sociodemographic representativeness of participants.
在绘制人群健康状况的调查中，调查管理方式的选择可能会影响参与率以及结果的普遍性。这项随机研究旨在调查三封数字信件（单模式管理）是否与两封数字信件和三封实体信件（顺序混合模式管理）的参与率相似，后者在提醒之间的时间间隔更短。
共有9489名参与2017年丹麦首都地区健康调查的个体被随机分配在2021年重新受邀参与调查（年龄≥20岁），其中一组通过三封数字信件进行单模式管理（N = 4745），另一组通过两封数字信件然后三封实体信件进行顺序混合模式调查管理（N = 4744）。为了调查调查管理方式对代表性的影响，比较了两组参与者的社会人口学特征（年龄、性别、原籍国、教育程度、劳动力市场参与情况）。使用广义线性模型估计两组管理方式在参与率（总体参与率以及提醒后的增加率）方面的绝对和相对差异。还调查了社会人口学因素是否调节了管理方式组与参与率之间的关联。
在随访结束时，接受五封信的顺序混合模式组的参与率（78%）显著高于接受三封信的单模式组（61%），这主要是因为在切换到实体信件管理后参与率有更大幅度的增加，以及混合模式组在额外两次提醒后参与率增加。总体而言，决定参与两组调查的个体在所有社会人口学因素方面具有可比性，但年龄较大的参与者似乎从切换到实体信件管理中受益更多，而年龄较小的参与者从额外提醒中受益更多。
根据目标人群的不同，可以考虑采用顺序混合模式调查管理和/或多次提醒来提高参与率；然而，这并不一定会提高参与者的社会人口学代表性。
