Abstract
Objectives To provide a comprehensive and objective summary of contraceptive failure rates for a variety of methods based on a systematic review of the literature.
Methods Medline and Embase were searched using the Ovid interface from January 1990 to February 2008, as well as the reference lists of published articles, to identify studies reporting contraceptive efficacy as a Pearl Index or life-table estimate. Reports that recruited less than 400 subjects per study group and those covering less than six cycles/six months were excluded. In addition, unlicensed products or those not internationally available, emergency contraception, and vasectomy studies were excluded.
Results Information was identified and extracted from 139 studies. One-year Pearl Indices reported for short-acting user-dependent hormonal methods were generally less than 2.5. Gross life-table rates for long-acting hormonal methods (implants and the levonorgestrel releasing-intrauterine system [LNG-IUS]) generally ranged between 0–0.6 per 100 at one year, but wider ranges (0.1–1.5 per 100) were observed for the copper intrauterine devices (0.1–1.4 per 100 for Cu-IUDs with surface area ≥300 mmCitation and 0.6–1.5 per 100 for those with surface area <300 mmCitation). Barrier and natural methods were the least effective.
Conclusions Our review broadly confirms the hierarchy of contraceptive effectiveness in descending order as: (1) female sterilisation, long-acting hormonal contraceptives (LNG-IUS and implants); (2) Cu-IUDs with ≥300 mmCitation surface area; (3) Cu-IUDs with <300 mmCitation surface area and short-acting hormonal contraceptives (injectables, oral contraceptives, the patch and vaginal ring), and (4) barrier methods and natural methods.
Declaration of interest: Dr Mansour has received support to undertake research, attend clinical meetings and scientific advisory boards for Bayer Schering Pharma AG, Dr Gemzell-Danielsson has participated on scientific advisory boards for both Bayer Schering Pharma AG and Organon, and Dr Pirjo Inki is an employee of Bayer Schering Pharma AG.
Editorial assistance for the development of this manuscript was provided by Richard Glover of Wolters Kluwer, with the financial support of Bayer Schering Pharma AG.