Abstract
Objectives: To assess the effectiveness of sending electronic prompts to randomized controlled trial participants to return study
questionnaires.
Study Design and Setting: A ‘‘trial within a trial’’ embedded within a study determining the effectiveness of chronic obstructive pulmonary
disease (DOC) screening on smoking cessation. Those participants taking part in DOC who provided a mobile phone number and/
or an electronic mail address were randomized to either receive an electronic prompt or no electronic prompt to return a study questionnaire.
The results were combined with two previous studies in a meta-analysis.
Results: A total of 437 participants were randomized: 226 to the electronic prompt group and 211 to the control group. A total of 285
(65.2%) participants returned the follow-up questionnaire: 157 (69.5%) in the electronic prompt group and 128 (60.7%) in the control group
[difference 8.8%; 95% confidence interval (CI): 0.11%, 17.7%; P 5 0.05]. The mean time to response was 23 days in the electronic
prompt group and 33 days in the control group (hazard ratio 5 1.27; 95% CI: 1.105, 1.47). The meta-analysis of all three studies showed
an increase in response rate of 7.1% (95% CI: 0.8%, 13.3%).
Conclusion: The use of electronic prompts increased response rates and reduces the time to response. 2015 Elsevier Inc. All
rights reserved.