Perfect- and typical-use effectiveness of the Dot fertility app over 13 cycles: results from a prospective contraceptive effectiveness trial

Abstract

Objective: Dynamic Optimal Timing (Dot) is a smartphone application (app) that estimates the menstrual cycle fertile window based on the user's menstrual period start dates. Dot uses machine learning to adapt to cycles over time and informs users of 'low' and 'high' fertility days. We investigated Dot's effectiveness, calculating perfect-and typical-use failure rates. Methods: This prospective, 13 cycle observational study (ClinicalTrials.gov NCT02833922) followed 718 women who were using Dot to prevent pregnancy. Participants contributed 6616 cycles between February 2017 and October 2018, providing data on menstrual period start dates, daily sexual activity and prospective intent to prevent pregnancy. We determined pregnancy through participant-administered urine pregnancy tests and/or written or verbal confirmation. We calculated perfect-and typical-use failure rates using multi-censoring, single-decrement life-table analysis, and conducted sensitivity, attrition and survival analyses. Results: The perfect-use failure rate was calculated to be 1.0% (95% confidence interval [CI]: 0.9%, 2.9%) and the typical-use failure rate was 5.8% (95% CI: 3.57%, 8.09%) for women aged 18-39 (n ¼ 718). Survival analyses identified no significant differences among age or racial/ethnic groups or women in different types of relationships. Attrition analyses revealed no significant sociodemographic differences, except in age, between women completing 13 cycles and those exiting the study earlier. Conclusion: Dot's effectiveness is within the range of other user-initiated contraceptive methods. ARTICLE HISTORY

Use of menstruation and fertility app trackers: a scoping review of the evidence

“…Li et al 21 describe several simulation studies using this method to estimate its efficacy in preventing pregnancy. Jennings et al 16 presents the findings from a prospective 13-cycle contraceptive effectiveness trial. At the time of writing, the Dot app has not received either European certification or FDA approval and some concerns have been expressed within the press about the marketing of the app to prevent pregnancies 33…”

“…Five hundred (n=500) records did not meet the inclusion criteria. Nineteen papers were initially identified for inclusion, but one was rejected since it reported interim data from a study which was then published in full 2 months later 16. Eighteen (n=18) records met the criteria for inclusion and are examined in this scoping review (figure 1).…”

“…Three papers report data from their respective studies on the NaturalCycles app 17–19. Similarly, two papers report their individual studies on the Dot app 16 20. Summaries of all the selected papers are given in table 3.…”

“…More than half of the papers in the review address the issue of pregnancy prevention,16–20 although some of these apps address both prevention and planning and these have been discussed above 24 29 30…”

Current Resources for Evidence‐Based Practice, July/August 2020

“…This app uses date of menses and a proprietary algorithm to calculate fertile days. A one‐year study of over 700 DOT users found a typical use failure rate of 5.8% (95% CI, 3.6% – 8.1%) 11 . The DOT website currently shows that the standalone app is no longer available.…”