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Randomized Controlled Trial
. 2023 Jul 26;24(1):477.
doi: 10.1186/s13063-023-07390-1.

Pre-notifications increase retention in a 17-year follow-up of adolescents born very preterm

Minttu Helin  1 , Max Karukivi  2 , Päivi Rautava  3   4 , Milka Hirvonen  5 , Mira Huhtala  6 , Sirkku Setänen  7 ; PIPARI Study Group
Collaborators, Affiliations
Randomized Controlled Trial

Pre-notifications increase retention in a 17-year follow-up of adolescents born very preterm

Minttu Helin et al. Trials. .

Abstract

Objective: Retention is essential in follow-up studies to reduce missing data, which can cause bias and limit the generalizability of the results. We investigated whether pre-notification letters would increase the response rates of approval forms and questionnaires and reduce the need for post-notifications in a prospective follow-up study of 17-year-old adolescents.

Study design: and settings This long-term follow-up study included 269 adolescents were randomized (1:1) into a pre-notification group (n = 132) and a no pre-notification group (n = 137). The pre-notification letter was sent prior to the approval form and questionnaires. The outcome measures were the response rates to the approval forms and questionnaires and the rate of post-notifications required.

Results: The adolescents who received the pre-notifications were more likely to return approval forms (n = 88/132, 67%) than the adolescents who did not receive the pre-notifications (n = 79/137, 58%) (OR 1.5, 95% CI 0.9-2.4). The rates of returned questionnaires were higher in the pre-notification group (n = 82/88, 93%) than in the no pre-notification group (n = 68/79, 86%) (OR 2.2, 95% CI 0.8-6.3). The adolescents who did not receive the pre-notifications were more likely to need the post-notifications than the adolescents who received the pre-notifications (OR 3.0, 95% CI 1.4 to 6.5).

Conclusions: Pre-notifications decreased the need for post-notifications and may increase retention in 17-year-old adolescents. Based on our findings, pre-notification letters are recommended in future follow-up studies in adolescents.

Trial registration: The Ethics Review Committee of the Hospital District of South-West Finland approved the 17-year PIPARI Study protocol in January 2018 (23.1.2018; 2/180/2012). The study has been registered to the SWAT repository as SWAT 179. Filetoupload,1457904,en.pdf (qub.ac.uk).

Keywords: Approval form; Long-term follow-up; Post-notification; Questionnaire; Response rate; Very preterm.

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Conflict of interest statement

The authors declare that they have no competing interests.

Figures

Fig. 1
Fig. 1
The study protocol of the host PIPARI Study of very preterm infants. Abbreviations with references are in Additional file 1. At the 17-year age-point (between January 2019 and December 2021), all the adolescents born between 2002 and 2004 and their parents who participated in the host PIPARI Study were included in this study. They were randomized into two groups (1:1): a pre-notification (n = 132 adolescents) and a no pre-notification (n = 137 adolescents). In the pre-notification group, adolescents were sent a pre-notification letter before the written information, the approval form, and the follow-up questionnaires. The Ethics Review Committee of the Hospital District of South-West Finland approved the 17-year PIPARI Study protocol in January 2018 (23.1.2018; 2/180/2012)
Fig. 2
Fig. 2
Flowchart of the study participants
Fig. 3
Fig. 3
The flowchart of the Study protocol
See this image and copyright information in PMC

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