The effect of using social pressure in cover letters to improve retention in a longitudinal health study: an embedded randomised controlled retention trial
Abstract Background Retention of participants in cohort studies is important for validity. One way to promote retention is by sending a persuasive cover letter with surveys. The study aimed to compare the effectiveness of a covering letter containing social pressure with a standard covering letter o...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
BMC
2017-07-01
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| Series: | Trials |
| Subjects: | |
| Online Access: | http://link.springer.com/article/10.1186/s13063-017-2090-5 |