A randomized controlled trial of daily text messages versus monthly paper diaries to collect bleeding data after intrauterine device insertion.

Bleeding data in contraceptive trials are often collected using daily diaries, but data quality may vary due to compliance and recall bias. Text messaging is a widespread and promising modality for data collection. This trial randomized participants 1:1 to use text messages or paper diaries to report on bleeding experienced during the 90 days after intrauterine device (IUD) insertion. Participants chose either the copper T380A or the 52-mg levonorgestrel IUD. Our primary outcome was number of days of reported bleeding data. We hypothesized that data gathered with daily text messages would have fewer missing values than paper diaries. Intention to treat analyses used the rank-sum test to compare medians. Two hundred thirty women enrolled, and randomization yielded groups similar in baseline characteristics. Twenty percent of participants provided no bleeding data; of these, 77% were assigned to paper diaries. With 90 days of reporting, approximately 20% in each group provided complete bleeding data. The text group reported a median of 82 days [interquartile range (IQR) 40-89] and the paper group reported a median of 36 days (IQR 0-88) (p≤.001). The number of responses received decreased gradually over the 90-day period but was always higher in the text group. Women who had attained higher levels of education did well regardless of data collection modality, while response rates of text messages were greater among those with a high school education or less (p<.01). Participants reporting bleeding via text messages provided more complete data than women using paper diaries. Depending on resources and population of interest, text messages may be a useful modality to improve data collection for patient-reported outcomes.