Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

OBJECTIVES: The objective of this study was to assess whether timing of short messaging service (SMS) reminders improved postal questionnaire return rates from participants in a randomized controlled trial (RCT). STUDY DESIGN AND SETTING: A Study Within A Trial (SWAT) embedded in a multicenter RCT evaluating three treatments for the frozen shoulder. Participants who provided a mobile telephone number were randomized to either prenotification SMS on the day of the questionnaire mail-out or postnotification SMS 4 days after questionnaire mail-out for the 3-month follow-up. The primary outcome was the proportion of participants who returned a valid questionnaire. A systematic review was undertaken to identify other embedded trials to perform a meta-analysis. RESULTS: Of the 269 participants, 122/135 (90.4%) returned a valid questionnaire in the prenotification arm and 119/134 (88.8%) in the postnotification arm (difference of -1.6%; 95% CI of difference: -8.9%, 5.7%). There was no difference in time to response (HR = 1.04; 95% CI: 0.80 to 1.34) or need for additional reminders (OR = 0.71; 95% CI: 0.43 to 1.17). Meta-analysis of two RCTs showed no difference in response rates between prenotification and postnotification reminders (OR = 0.78 95% CI: 0.42 to 1.45). CONCLUSION: Timing of SMS reminders did not improve response rates and time to response or affect the need for additional reminders.

Original publication

DOI

10.1016/j.jclinepi.2020.03.001

Type

Journal article

Journal

J clin epidemiol

Publication Date

06/2020

Volume

122

Pages

70 - 77

Keywords

Meta-analyses, Randomized controlled trial, Retention, SMS, Study Within A Trial, Text message