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  1. 1
    Peer Reviewed

    Implantable contraceptives for women.

    Meirik O; Fraser IS; d'Arcangues C

    Human Reproduction Update. 2003 Jan-Feb; 9(1):49-59.

    Progestogen-only implantable contraceptives are used by increasing numbers of women worldwide. This review outlines the evidence accumulated on these methods to date. Reviews of toxicological evaluations, clinical trials, endocrinological, epidemiological and social science studies, as well as operations research and economic evaluation were undertaken in preparation for an Expert Consultation convened by the World Health Organization in 2001. At the meeting, these reviews were further evaluated and the research results summarized in this consensus paper. A large body of evidence demonstrates the high contraceptive effectiveness and safety of the 5-year levonorgestrel-releasing implants Norplant and Jadelle. Information on the 3-year etonogestrel-releasing implant Implanon is more limited, but suggests that this implant has a high contraceptive effectiveness and a satisfactory safety pro®le. Information available on levonorgestrel-releasing implants manufactured and approved in China suggests that their clinical performance is satisfactory, but was insufficient to allow their full safety assessment. For all implants, there is insufficient information on their use by women with medical conditions. Provision of contraceptive implants requires good quality family planning services and specific provider training.
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  2. 2

    Effects of quadrivalent human papillomavirus vaccination. Authors' reply [letter]

    Ault K; Insinga R; Haupt R; Lupinacci L; Barr E

    Lancet. 2007 Sep 22; 370(9592):1032-1033.

    Cost-effectiveness analysis, as referenced by Davide Mauri and Nikolaos Polyzos, constitutes one of several sources of information considered by policymakers in developing and developed worlds in making decisions about the optimum efficient use of health-care resources. The WHO Commission on Macroeconomics and Health has suggested that interventions costing less than three times a country's per capita gross domestic product per disability-adjusted life year gained can be regarded as good value, and analysts have equivalently applied this threshold to analyses that use quality-adjusted life years (QALYs). Preliminary results from a cost-effectiveness analysis of vaccination with quadrivalent HPV 6/11/16/18 vaccine in Mexico suggest a cost/QALY ratio well below this threshold in that country. Previous analyses in developed world settings have consistently shown that vaccination of girls and young women has a cost-effectiveness ratio within the range typically regarded as cost-effective. In countrieswith the fewest resources, direct assistance and public-private partnerships can help deliver needed medicines to the population at or below development costs-eg, the ivermectin donation for river blindness. Marc Arbyn states that if the cases of vaccine-type-related disease are subtracted from disease due to all types, there are a larger number of cases in women who received vaccine than in those who received placebo. This subtraction assumes that the subset of disease cases due to vaccine HPV types and the subset of cases due to non-vaccine HPV types are mutually exclusive, which is not the case. Coinfections with vaccine and non-vaccine types are common. In the presence of coinfection, the effect of such a subtraction is to ignore the presence of non-vaccine HPV types in disease where a vaccine-type HPV has also been detected. The effect of the subtraction is to preferentially attribute co-infected disease cases only to the vaccine HPV types. Individuals in the placebo group are more likely to have their non-vaccine type-related disease discounted in this way. Owing to the high efficacy of the vaccine, individuals in the vaccine group have less vaccine-type-related disease, and so those in the vaccine group have fewer such coinfection cases. To illustrate this point, an analysis of the numbers of individuals with disease due to vaccine and non-vaccine HPV types in the intention-to-treat population of protocols 013 and 015 is presented in the figure. The parts shaded blue would be the result of subtraction, similar to Arbyn's subtraction. However, the total numbers of cases of disease related to non-vaccine HPV types are 226+56=282 cases in the vaccine group and 193+106=299 cases in the placebo group. There is not an excess of cases caused by non-vaccine HPV types in the vaccine group. (full text)
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  3. 3

    Cervical cancer, human papillomavirus, and vaccination. Vaccines work, but we need more information before widespread immunisation [editorial]

    Lowndes CM; Gill ON

    BMJ. British Medical Journal. 2005 Oct 22; 331(7522):915-916.

    At the beginning of October one of the trials of vaccines against human papillomavirus (HPV) infection, the primary risk factor for cervical cancer, announced an encouraging result. Large scale, multi-country, multi-site trials of several HPV vaccines are currently under way. The end points comprise incident and persistent HPV infection (during 2-3 years’ follow-up) and associated precancerous cytological and histological lesions (cervical intraepithelial (CIN) neoplasia during 2-3 and 4-5 years’ follow-up). The World Health Organization is expecting at least one of these vaccines to be licensed for use in 2006. How promising are the available trial results? What other questions need answering? And is it time to accelerate preparations for programmes to provide HPV vaccination? The latest data release concerns a trial of a quadrivalent recombinant vaccine that included HPV types 6, 11, 16, and 18. In all, 12,167 women at 90 centres in 13 countries participated in the trial, the FUTURE II study. In this prospective double blind study, women aged 16 to 26 were randomised to receive three doses of either vaccine or placebo over six months. (excerpt)
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  4. 4
    Peer Reviewed

    Meta-analyses of randomized trials comparing different doses of mifepristone in emergency contraception.

    Piaggio G; von Hertzen H; Heng Z; Xiao B; Cheng L

    Contraception. 2003 Dec; 68(6):447-452.

    There is some evidence from randomized trials that different doses of mifepristone for emergency contraception do not differ in efficacy in the range from 10 mg to 600 mg. Lower doses have a better side effect profile and are cheaper and therefore they would be preferable in the absence of a dose effect. However, the lack of significance is not evidence of absence of an effect. More evidence can be obtained by combining results of trials. We present meta-analyses of randomized trials comparing doses of mifepristone for emergency contraception from 5 mg to 600 mg, with regard to the efficacy to prevent unwanted pregnancies. We use two approaches for analysis, one using only within-trial information and another one combining within-trial with between-trial information. We discuss the results in terms of equivalence. There is some evidence of a small dose effect on efficacy in the lower range of doses (<50 mg). The pregnancy rate increases by a factor of 1.6 when the dose of 10 mg is used instead of 25 mg (95% confidence interval: 1.1–2.4). In terms of the number of women needed to treat, however, using 10 mg in the place of 25 mg implies having one extra pregnancy every 146 women requesting emergency contraception, which might be a low cost compared to the benefit of more women having access to treatment. (author's)
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  5. 5
    Peer Reviewed

    Combined estimates of effectiveness of mifepristone 10 mg in emergency contraception.

    Piaggio G; Heng Z; von Hertzen H; Xiao B; Cheng L

    Contraception. 2003 Dec; 68(6):439-446.

    The present paper combines the estimates of efficacy and side effects of 10 mg mifepristone for emergency contraception obtained from randomized trials. A total of 6083 women participating in 12 randomized trials and receiving 10 mg mifepristone for emergency contraception up to 120 h after intercourse, were analyzed for efficacy. Between 4188 and 5833 women were analyzed for side effects and 3601 for delay of menses of more than 7 days. Prevented fractions, the effect of delay and of further acts of intercourse after treatment administration were analyzed in 3440 women, using individual data. The combined pregnancy rate from all the 12 trials was 1.7% [101/6083, 95% confidence interval (CI): 1.3–2.2]. From the three trials providing individual data, the combined pregnancy rate was 1.3% (45/3440, 95% CI: 0.9 –1.7) and the estimate of pregnancies prevented was 83.4% (95% CI: 77.4–87.8). There was a sharp decline in efficacy when treatment was administered during the 5th day after intercourse compared to administration during the 1st day, the odds of pregnancy increasing by a factor of 5.3 (95% CI: 1.9 –14.9). The relative risk of pregnancy was about 28 times higher among women with unprotected acts of coitus between treatment administration and the onset of next menses, compared with women reporting none [odds ratio (OR) = 27.6, 95% CI: 12.7– 60.2]. The increase in risk for women reporting protected acts of intercourse during this interval was not statistically significant (OR = 1.8, 95% CI: 0.9 –3.8). There was a large heterogeneity among trials in all side effects and delay of menses of more than 7 days (all had p < 0.0001 for the test of homogeneity). The percentage of women with nausea ranged from 0.0–19.4% (highest upper 95% confidence limit: 23.0%), that of vomiting from 0.0–4.3% (highest upper 95% confidence limit: 6.1%), that of lower abdominal pain from 4.3–19.1% (highest upper 95% confidence limit: 22.7%). The percentage of women with delay of menses of more than 7 days ranged from 4.3–25.8% (highest upper 95% confidence limit: 34.1%). We conclude that 10 mg mifepristone is an effective emergency contraception regimen, with an acceptable side-effects profile. Postponing treatment until the 5th day seriously decreases efficacy. The risk of pregnancy is dramatically increased among women having unprotected acts of intercourse between treatment administration and the onset of next menses. This risk may be enhanced for women whose ovulation is postponed by treatment. (author's)
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  6. 6

    Study of side-effects of vaginal microbicide.


    In January 1994, a clinical trial was launched in Amsterdam, Antwerp, and Bangkok to study the side effects of 2 weeks of daily use of Nonoxynol-9. A total of 300 women will be examined for scars and other damage caused by the Nonoxynol to the vaginal linings. Nonoxynol is known to kill sperm, and it was found to kill HIV in vitro in 1985. The World Health Organization (WHO) intends to develop Nonoxynol as a vaginal microbicide for women's protection against infection with HIV during vaginal penetration. The WHO has charged three university hospitals with the study of the effects to the vagina of a daily dose of 50mc to ascertain if Nonoxynol is worth developing as a microbicide. In the Netherlands, nonpregnant women aged 18-45 were solicited to participate. They were told to continue using their regular contraceptive. However, nobody mentioned the possibility that these women could be at risk of contracting HIV, as only one of them claimed to use condoms consistently. Questions remain unanswered as to the use and development of vaginal microbicides. The method is meant to increase women's autonomy in the prevention of HIV infection and empower them regarding their sexuality. It is doubtful whether the method's availability, cost, and resistance to heat and humidity have been considered. The WHO insists the vaginal microbicides are not meant to replace condoms, but it is certain at this moment that women are again targeted in the battle against the spread of AIDS.
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