ReviewContraception2013
The creeping Pearl: Why has the rate of contraceptive failure increased in clinical trials of combined hormonal contraceptive pills?
Review in Contraception, 2013. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 23 papers.
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.
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.
Who cites it
23 citing papers in PubMed.
- We should really keep in touch: predictors of the ability to maintain contact with contraception clinical trial participants over 12 months.Contraception · 2014Trial
- Different Pearl Indices in studies of hormonal contraceptives in the United States: impact of study population.Contraception · 2014Trial
- Combined hormonal versus nonhormonal versus progestin-only contraceptives for postpartum contraception in lactating individuals.The Cochrane database of systematic reviews · 2026Article
- Three-Year Contraceptive Failure Rates During the HER Salt Lake Contraceptive Initiative.JAMA network open · 2026Article
- Real-world contraceptive performance of ormeloxifene among reproductive-age women.The Indian journal of medical research · 2025Article
- Presence of Drug Interaction Between Penicillin and Hormonal Contraceptives in Women: A Scoping Review.Healthcare (Basel, Switzerland) · 2025Review
- Multipurpose prevention technologies for the prevention of unintended pregnancy, HIV, and other sexually transmitted infections: regulatory pathways and challenges.Frontiers in reproductive health · 2025Article
- Evaluating Pregnancy Rates in Fertility Awareness-Based Methods for Family Planning: Simulated Comparison of Correct Use to Avoid, Method-Related, and Total Pregnancy Rates.The Linacre quarterly · 2024Article
- Long-acting intramuscular injections of ELQ-331, an antimalarial agent.European journal of pharmaceutical sciences : official journal of the European Federation for Pharmaceutical Sciences · 2024Article
- The benefits of estetrol addition to drospirenone for contraception.AJOG global reports · 2023Article
- Natural Family Planning, An Option in Reproductive Healthcare: A Qualitative Study on Clinicians' Perceptions.The Linacre quarterly · 2022Article
- New Contraception Update - Annovera, Phexxi, Slynd, and Twirla.Current obstetrics and gynecology reports · 2022Article
- Antiseizure medications and oral contraceptives: Impact of enzyme inducers on pregnancy outcomes and costs.Epilepsy & behavior : E&B · 2021Article
- Quantitative Assessment of Levonorgestrel Binding Partner Interplay and Drug-Drug Interactions Using Physiologically Based Pharmacokinetic Modeling.CPT: pharmacometrics & systems pharmacology · 2021Article
- A novel vaginal pH regulator: results from the phase 3 AMPOWER contraception clinical trial.Contraception: X · 2020Article
- A 1-year prospective, open-label, single-arm, multicenter, phase 3 trial of the contraceptive efficacy and safety of the oral progestin-only pill drospirenone 4 mg using a 24/4-day regimen.Contraception: X · 2020Article
- Efficacy of the 1-year (13-cycle) segesterone acetate and ethinylestradiol contraceptive vaginal system: results of two multicentre, open-label, single-arm, phase 3 trials.The Lancet. Global health · 2019Article
- Published analysis of contraceptive effectiveness of Daysy and DaysyView app is fatally flawed.Reproductive health · 2018Article
- The emerging role of obesity in short-acting hormonal contraceptive effectiveness.Contraception · 2018Article
- Improving usability and pregnancy rates of a fertility monitor by an additional mobile application: results of a retrospective efficacy study of Daysy and DaysyView app.Reproductive health · 2018Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
2 authors.
Funding
Abstract
backgroundDespite several drawbacks, the Pearl Index continues to be the most widely used statistical measure of contraceptive failure. However, Pearl indices reported in studies of newer hormonal contraceptives appear to be increasing. STUDY
designWe searched PubMed and Medical Intelligence Solutions databases for prospective trials evaluating oral contraceptive (OC) efficacy to examine potential factors that could contribute to increasing Pearl indices.
resultsNumerous potential factors were identified, including an increased rate of failures of newer OCs, deficiencies in methods of calculating contraceptive failure rates, differences in study design and changes in patient populations resulting in increased rates of contraceptive failures due to the inappropriate or inconsistent use of the method.
conclusionsThe two most likely important contributors to the increase in Pearl indices are more frequent pregnancy testing with more sensitive tests and less adherent study populations. Because study populations appear to be increasingly representative of the likely actual users once the product is marketed, we can expect to see even higher failure rates in ongoing and future studies. This result poses challenges for companies and regulatory agencies.
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What OpenQuestion holds
Registered trials
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.