Evidence map›Paper›PMID 30904873›Full record

ArticleBMJ open2019

Typical use effectiveness of Natural Cycles: postmarket surveillance study investigating the impact of previous contraceptive choice on the risk of unintended pregnancy.

Jonathan Bull, Simon Rowland, Olof Lundberg, Elina Berglund-Scherwitzl, Kristina Gemzell-Danielsson, James Trussell, Raoul Scherwitzl

Erratum issuedAbstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in BMJ open, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. An erratum has been issued. Cited by 7 papers, 2 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
7citing papers in PubMed, 2 pooled it
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

7 citing papers in PubMed, 2 syntheses or guidelines pooled it.

  1. Pooled it
  2. Pooled it
  3. Review
  4. Review
  5. Article
  6. Review
  7. Article
4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

7 authors.

Jonathan BullDepartment of Medical Communications, Natural Cycles Nordic AB, Stockholm, Sweden.ORCID 0000-0001-9992-3769
Simon RowlandDepartment of Medical Communications, Natural Cycles Nordic AB, Stockholm, Sweden.
Olof LundbergDepartment of Medical Communications, Natural Cycles Nordic AB, Stockholm, Sweden.
Elina Berglund-ScherwitzlDepartment of Medical Communications, Natural Cycles Nordic AB, Stockholm, Sweden.
Kristina Gemzell-DanielssonDepartment of Women's and Children's Health, Karolinska Universitetssjukhuset, Stockholm, Sweden.
James TrussellOffice of Population Research, Princeton University, Princeton, New Jersey, USA.
Raoul ScherwitzlDepartment of Medical Communications, Natural Cycles Nordic AB, Stockholm, Sweden.

Funding

Scientific and Technical Computing CoreP2CHD047879 · NICHD · PRINCETON UNIVERSITY · PI SALGANIK, MATTHEW J. · 2014 to 2018
$2.0M
NICHD NIH HHS P2C HD047879
6 · The paper itself

Abstract

objectiveTo 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.

settingNatural Cycles mobile application.

participants16 331 Natural Cycles users in Sweden for the prevention of pregnancy. OUTCOME MEASURES: Risk of unintended pregnancy. STUDY

designReal 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.

resultsFor 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.

conclusionThe 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.

Indexed as

Contraception BehaviorMenstrual CycleMobile ApplicationsPregnancy, UnplannedSafe SexAdolescentAdultCondomsContraceptionContraceptive AgentsFamily Planning ServicesFemaleFertilityHumansMiddle AgedPregnancyContraceptive Agentscontraceptionfamily planningfertility appfertility awarenessinformation technologytelemedicine

Identifiers

PMID30904873
PMCPMC6475236

What OpenQuestion holds

Textmetadata
LicenceCC BY-NC
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.