VIVE-The Danish Center for Social Science Research, Copenhagen, Denmark.
PLoS One. 2020 May 12;15(5):e0233025. doi: 10.1371/journal.pone.0233025. eCollection 2020.
In surveys non-responders may introduce bias and lower the validity of the studies. Ways to increase response rates are therefore important. The purpose of the study was to investigate if an unconditional monetary incentive can increase the response rate for vulnerable children and youths in a postal questionnaire survey.
The study was designed as a randomized controlled trial. The study population consisted of 262 children and youth who participated in an established intervention study aimed at creating networks for different groups of vulnerable children and youths. The mean age of the participants was 16.7 years (range 11-28) and 67.9% were female. The questionnaire was adapted to three different age groups and covered different aspects of the participants' life situation, including the dimensions from the Strengths and Difficulties Questionnaire (SDQ). In the follow-up survey, participants were randomly allocated to two groups that either received a €15 voucher for a supermarket together with the questionnaire or only received the questionnaire. We used Poisson regression to estimate the differences in response rate (Rate Ratio RR) between the intervention group and the control group.
The response rate was 75.5% in the intervention group and 42.9% in the control group. The response rate in the intervention group was significantly higher than in the control group when adjusting for age and gender (Rate Ratio, RR 1.73; 95% CI 1.38-2.17). We did not find any significant differences in scales scores between the two groups for the five scales of the SDQ. In stratified analyses, we found the effect of the incentive to be higher for males (RR 2.81; 95% CI 1.61-4.91) than for females (1.43; 95% CI 1.12-1.84).
Monetary incentives can increase the response rate for vulnerable children and youths in surveys.
The trial was retrospectively registered at ClinicalTrials.gov Identifier: NCT01741675.
在调查中，不回复者可能会引入偏差，降低研究的有效性。因此，提高回复率的方法很重要。本研究旨在探讨无条件的金钱激励是否可以提高弱势儿童和青少年在邮寄问卷调查中的回复率。
本研究设计为随机对照试验。研究人群由 262 名参与既定干预研究的儿童和青少年组成，该研究旨在为不同群体的弱势儿童和青少年建立网络。参与者的平均年龄为 16.7 岁（范围 11-28 岁），其中 67.9%为女性。问卷适用于三个不同的年龄组，涵盖了参与者生活状况的不同方面，包括《优势与困难问卷》（SDQ）的各个维度。在随访调查中，参与者被随机分配到两个组，一组在收到问卷的同时收到一张 15 欧元的超市代金券，另一组仅收到问卷。我们使用泊松回归来估计干预组和对照组之间回复率（率比 RR）的差异。
干预组的回复率为 75.5%，对照组为 42.9%。调整年龄和性别后，干预组的回复率显著高于对照组（率比，RR 1.73；95%置信区间 1.38-2.17）。我们未发现两组在 SDQ 的五个量表的任何显著差异。在分层分析中，我们发现激励对男性的影响更高（RR 2.81；95%置信区间 1.61-4.91），而对女性的影响较低（1.43；95%置信区间 1.12-1.84）。
金钱激励可以提高弱势儿童和青少年在调查中的回复率。
该试验在 ClinicalTrials.gov 注册号为 NCT01741675 进行了回顾性注册。
