Typical use effectiveness of Natural Cycles: postmarket surveillance study investigating the impact of previous contraceptive choice on the risk of unintended pregnancy
Objective To investigate the association between contraceptive effectiveness of Natural Cycles and users’ previous choice of contraceptive, and to evaluate the impact of shifting from other methods to Natural Cycles on the risk of unintended pregnancy.Setting Natural Cycles mobile application.Partic...
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| Format: | Article |
| Language: | English |
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BMJ Publishing Group
2019-03-01
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| Series: | BMJ Open |
| Online Access: | https://bmjopen.bmj.com/content/9/3/e026474.full |
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| author | Simon Rowland Raoul Scherwitzl Kristina Gemzell-Danielsson Jonathan Bull Olof Lundberg Elina Berglund-Scherwitzl James Trussell |
| author_facet | Simon Rowland Raoul Scherwitzl Kristina Gemzell-Danielsson Jonathan Bull Olof Lundberg Elina Berglund-Scherwitzl James Trussell |
| author_sort | Simon Rowland |
| collection | DOAJ |
| description | Objective To investigate the association between contraceptive effectiveness of Natural Cycles and users’ previous choice of contraceptive, and to evaluate the impact of shifting from other methods to Natural Cycles on the risk of unintended pregnancy.Setting Natural Cycles mobile application.Participants 16 331 Natural Cycles users in Sweden for the prevention of pregnancy.Outcome measures Risk of unintended pregnancy.Study design Real world evidence was collected from Natural Cycles users regarding contraceptive use prior to using Natural Cycles and sexual activity while using Natural Cycles. We calculated the typical use 1-year Pearl Index (PI) and 13-cycle failure rate of Natural Cycles for each cohort. The PI was compared with the population PI of their stated previous methods.Results For women who had used condoms before, the PI of Natural Cycles was the lowest at 3.5±0.5. For women who had used the pill before, the PI of Natural Cycles was the highest at 8.1±0.6. The frequency of unprotected sex on fertile days partially explained some of the observed variation in PI between cohorts. 89% of users switched to Natural Cycles from methods with higher or similar reported PIs.Conclusion The effectiveness of Natural Cycles is influenced by previous contraceptive choice and this should be considered when evaluating the suitability of the method for the individual. We estimate that Natural Cycles usage can reduce the overall likelihood of having an unintended pregnancy by shifting usage from less effective methods. |
| format | Article |
| id | doaj-art-095a324a0b27478da90484d8a6063548 |
| institution | Kabale University |
| issn | 2044-6055 |
| language | English |
| publishDate | 2019-03-01 |
| publisher | BMJ Publishing Group |
| record_format | Article |
| series | BMJ Open |
| spelling | doaj-art-095a324a0b27478da90484d8a60635482025-02-01T23:25:11ZengBMJ Publishing GroupBMJ Open2044-60552019-03-019310.1136/bmjopen-2018-026474Typical use effectiveness of Natural Cycles: postmarket surveillance study investigating the impact of previous contraceptive choice on the risk of unintended pregnancySimon Rowland0Raoul Scherwitzl1Kristina Gemzell-Danielsson2Jonathan Bull3Olof Lundberg4Elina Berglund-Scherwitzl5James Trussell61 Department of Medical Communications, Natural Cycles Nordic AB, Stockholm, Sweden1 Department of Medical Communications, Natural Cycles Nordic AB, Stockholm, SwedenWomen`s and Children`s Health, Karolinska Institute, Stockholm, Sweden1 Department of Medical Communications, Natural Cycles Nordic AB, Stockholm, Sweden1 Department of Medical Communications, Natural Cycles Nordic AB, Stockholm, Sweden1 Department of Medical Communications, Natural Cycles Nordic AB, Stockholm, SwedenOffice of Population Research, Princeton University, Princeton, New Jersey, USAObjective To investigate the association between contraceptive effectiveness of Natural Cycles and users’ previous choice of contraceptive, and to evaluate the impact of shifting from other methods to Natural Cycles on the risk of unintended pregnancy.Setting Natural Cycles mobile application.Participants 16 331 Natural Cycles users in Sweden for the prevention of pregnancy.Outcome measures Risk of unintended pregnancy.Study design Real world evidence was collected from Natural Cycles users regarding contraceptive use prior to using Natural Cycles and sexual activity while using Natural Cycles. We calculated the typical use 1-year Pearl Index (PI) and 13-cycle failure rate of Natural Cycles for each cohort. The PI was compared with the population PI of their stated previous methods.Results For women who had used condoms before, the PI of Natural Cycles was the lowest at 3.5±0.5. For women who had used the pill before, the PI of Natural Cycles was the highest at 8.1±0.6. The frequency of unprotected sex on fertile days partially explained some of the observed variation in PI between cohorts. 89% of users switched to Natural Cycles from methods with higher or similar reported PIs.Conclusion The effectiveness of Natural Cycles is influenced by previous contraceptive choice and this should be considered when evaluating the suitability of the method for the individual. We estimate that Natural Cycles usage can reduce the overall likelihood of having an unintended pregnancy by shifting usage from less effective methods.https://bmjopen.bmj.com/content/9/3/e026474.full |
| spellingShingle | Simon Rowland Raoul Scherwitzl Kristina Gemzell-Danielsson Jonathan Bull Olof Lundberg Elina Berglund-Scherwitzl James Trussell Typical use effectiveness of Natural Cycles: postmarket surveillance study investigating the impact of previous contraceptive choice on the risk of unintended pregnancy BMJ Open |
| title | Typical use effectiveness of Natural Cycles: postmarket surveillance study investigating the impact of previous contraceptive choice on the risk of unintended pregnancy |
| title_full | Typical use effectiveness of Natural Cycles: postmarket surveillance study investigating the impact of previous contraceptive choice on the risk of unintended pregnancy |
| title_fullStr | Typical use effectiveness of Natural Cycles: postmarket surveillance study investigating the impact of previous contraceptive choice on the risk of unintended pregnancy |
| title_full_unstemmed | Typical use effectiveness of Natural Cycles: postmarket surveillance study investigating the impact of previous contraceptive choice on the risk of unintended pregnancy |
| title_short | Typical use effectiveness of Natural Cycles: postmarket surveillance study investigating the impact of previous contraceptive choice on the risk of unintended pregnancy |
| title_sort | typical use effectiveness of natural cycles postmarket surveillance study investigating the impact of previous contraceptive choice on the risk of unintended pregnancy |
| url | https://bmjopen.bmj.com/content/9/3/e026474.full |
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