Association between the use of free-of-charge intrauterine devices and a history of induced abortion: a retrospective study.

BACKGROUND: To determine whether use of intrauterine device (IUD) is influenced by a history of induced abortion and the type of contraceptives used until costs are covered. METHODS: We analyzed data from 301 female residents in Mecklenburg-West Pomerania, an economically challenged community. The women, aged between 20 and 35 years, were entitled to receive unemployment benefits, and had access to free-of-charge oral contraceptives, ring or IUD. Cross-sectional data were analyzed using logistic regression. RESULTS: There were 112 (37.2%) women with a history of induced abortion, and 46 (15.3%) reported exclusively using less effective contraceptives (e.g. condoms). In a univariate logistic regression, use of an IUD was associated with a history of having had an induced abortion. Furthermore, uptake of an IUD was associated with women who had, until costs were covered, exclusively choice to use less effective contraceptives (OR = 3.281, 95% CI: 1.717; 6.273). Both associations remained significant in a multivariate model. CONCLUSIONS: Free contraceptives provided to women receiving unemployment benefits may increase the use of IUDs, especially among those with a history of an induced abortion and those using less effective contraceptives.

Evaluating the potential impact and cost-effectiveness of dapivirine vaginal ring pre-exposure prophylaxis for HIV prevention.

BACKGROUND: Expanded HIV prevention options are needed to increase uptake of HIV prevention among women, especially in generalized epidemics. As the dapivirine vaginal ring moves forward through regulatory review and open-label extension studies, the potential public health impact and cost-effectiveness of this new prevention method are not fully known. We used mathematical modeling to explore the impact and cost-effectiveness of the ring in different implementation scenarios alongside scale-up of other HIV prevention interventions. Given the knowledge gaps about key factors influencing the ring's implementation, including potential uptake and delivery costs, we engaged in a stakeholder consultation process to elicit plausible parameter ranges and explored scenarios to identify the possible range of impact, cost, and cost-effectiveness. METHODS AND FINDINGS: We used the Goals model to simulate scenarios of oral and ring pre-exposure prophylaxis (PrEP) implementation among female sex workers and among other women ≤21 years or >21 years with multiple male partners, in Kenya, South Africa, Uganda, and Zimbabwe. In these scenarios, we varied antiretroviral therapy (ART) coverage, dapivirine ring coverage and ring effectiveness (encompassing efficacy and adherence) by risk group. Following discussions with stakeholders, the maximum level of PrEP coverage (oral and/or ring) considered in each country was equal to modern contraception use minus condom use in the two age groups. We assessed results for 18 years, from 2018 to 2035. In South Africa, for example, the HIV infections averted by PrEP (ring plus oral PrEP) ranged from 310,000 under the highest-impact scenario (including ART held constant at 2017 levels, high ring coverage, and 85% ring effectiveness) to 55,000 under the lowest-impact scenario (including ART reaching the UNAIDS 90-90-90 targets by 2020, low ring coverage, and 30% ring effectiveness). This represented a range of 6.4% to 2.2% of new HIV infections averted. Given our assumptions, the addition of the ring results in 11% to 132% more impact than oral PrEP alone. The cost per HIV infection averted for the ring ranged from US$13,000 to US$121,000. CONCLUSIONS: This analysis offers a wide range of scenarios given the considerable uncertainty over ring uptake, consistency of use, and effectiveness, as well as HIV testing, prevention, and treatment use over the next two decades. This could help inform donors and implementers as they decide where to allocate resources in order to maximize the impact of the dapivirine ring in light of funding and implementation constraints. Better understanding of the cost and potential uptake of the intervention would improve our ability to estimate its cost-effectiveness and assess where it can have the most impact.

Dapivirine vaginal ring for HIV prevention: modelling health outcomes, drug resistance and cost-effectiveness.

INTRODUCTION: A vaginal ring containing dapivirine is effective for HIV prevention as pre-exposure prophylaxis (PrEP). We evaluated the potential epidemiological impact and cost-effectiveness of dapivirine vaginal ring PrEP among 22- to 45-year-old women in KwaZulu-Natal, South Africa. METHODS: Using mathematical modelling, we studied dapivirine vaginal ring PrEP implementation, either unprioritized, or prioritized based on HIV incidence (≥3% per year), age (22 to 29 years) or female sex worker status, alongside the implementation of voluntary medical male circumcision and antiretroviral therapy scaled-up to UNAIDS Fast-Track targets. Outcomes over the intervention (2019 to 2030) and lifetime horizons included cumulative HIV infections, life-years lived, costs and cost-effectiveness. We assessed the incremental cost-effectiveness ratios against the revealed willingness to pay ($500) and the standard (2017 per capita gross domestic product; $6161) cost-effectiveness thresholds for South Africa. RESULTS: Compared to a reference scenario without PrEP, implementation of dapivirine vaginal ring PrEP, assuming 56% effectiveness and covering 50% of 22 to 29-year-old or high-incidence women, prevented 10% or 11% of infections by 2030 respectively. Equivalent, unprioritized coverage (30%) prevented fewer infections (7%), whereas 50% coverage of female sex workers had the least impact (4%). Drug resistance attributable to PrEP was modest (2% to 4% of people living with drug-resistant HIV). Over the lifetime horizon, dapivirine PrEP implementation among female sex workers was cost-saving, whereas incidence-based PrEP cost $1898 per life-year gained, relative to PrEP among female sex workers and $989 versus the reference scenario. In a scenario of 37% PrEP effectiveness, PrEP had less impact, but prioritization to female sex workers remained cost-saving. In uncertainty analysis, female sex worker PrEP was consistently cost-saving; and over the lifetime horizon, PrEP cost less than $6161 per life-year gained in over 99% of simulations, whereas incidence- and age-based PrEP cost below $500 per life-year gained in 61% and 49% of simulations respectively. PrEP adherence and efficacy, and the effectiveness of antiretroviral therapy for HIV prevention, were the principal drivers of uncertainty in the cost-effectiveness of PrEP. CONCLUSIONS: Dapivirine vaginal ring PrEP would be cost-saving in KwaZulu-Natal if prioritized to female sex workers. PrEP's impact on HIV prevention would be increased, with potential affordability, if prioritized to women by age or incidence.

Put a Ring in It: Exploring Women's Experiences with the Contraceptive Vaginal Ring in Ontario.

BACKGROUND: Although the contraceptive vaginal ring (CVR) has been available in Canada since 2001, overall use and availability remain low compared with other combined hormonal contraceptive methods. We aimed to explore women's experiences with the CVR in Ontario as well as factors that influenced their decisions to choose the method and continue/discontinue use. METHODS: We conducted a multimethod qualitative study that consisted of an anonymous online survey and in-depth telephone interviews with a subset of survey participants. We used descriptive statistics to analyze the survey data and analyzed our interviews for content and themes using both deductive and inductive techniques. RESULTS: From May to July 2015, we received 103 survey responses and conducted 29 in-depth interviews. Many participants described positive experiences with the CVR and found it to be an especially convenient method. Women who discontinued use of the CVR cited high costs, access barriers, and negative media reports as important factors in their decision. Our participants primarily relied on their physicians for contraceptive information but did not feel fully informed about potential side effects. Several women identified the CVR as an "in between" method in the transition from oral contraceptive pills to the intrauterine device. CONCLUSIONS: Our findings suggest that the CVR represents a convenient and desirable contraceptive option for some women. However, participants expressed a desire for health care providers to provide more comprehensive information about a full range of contraceptive methods. Improving access to a full range of low-cost contraceptives in Ontario seems to be warranted.

Stagnant contraceptive sales after the Zika epidemic in Brazil.

OBJECTIVES: Our aim was to assess national hormonal and non-hormonal contraceptive sales in Brazil after the Zika virus outbreak. METHODS: Pharmaceutical companies based in Brazil provided data on monthly sales from September 2016 to June 2017. Data from both the public and private sectors were obtained about sales of registered, available modern contraceptive methods: combined oral contraceptive pill; progestin-only pill; vaginal and transdermal contraceptives; injectable contraceptives; long-acting reversible contraceptive (LARC) methods, including the copper-releasing intrauterine device, the levonorgestrel-releasing intrauterine system and the etonogestrel-releasing subdermal implant; and emergency contraceptive pills. RESULTS: Seventy-eight percent of sales comprised pills, patches and vaginal rings (11.1-13.8 million cycles/units per month), followed by emergency contraceptive pills (1.8-2.6 million pills), injectables (1.2-1.4 million ampoules) and LARC methods (6500-17,000 devices). CONCLUSIONS: The data showed much higher sales of short-acting methods compared with more effective LARC methods. The public sector needs to strengthen its focus on ensuring better access to LARC methods through a systematic approach ensuring regular supply, improved professional skills and better demand generation to couples wishing to avoid or delay pregnancy. In Zika virus-affected areas, many women of reproductive age may want to delay or postpone pregnancy by using an effective LARC method. The public sector should review its policies on LARC, as the need for these methods especially in Zika virus endemic areas may increase. A clear emphasis on quality in services, access and use is warranted.

Implications of dispensing self-administered hormonal contraceptives in a 1-year supply: a California case study.

On September 23, 2016, California became the sixth state to pass legislation requiring health plans and insurers to cover a 12-month supply of FDA-approved self-administered hormonal contraceptives such as contraceptive pills, patches and vaginal rings. This legislation is estimated to result in 38% of current contraceptive pill, patch, and ring users receiving a 12-month supply dispensed at one time. This shift in dispensing patterns was estimated to result in a reduction of 15,000 unintended pregnancies; 2000 fewer miscarriages; and 7000 fewer abortions in California decreasing total net health care expenditures by 0.03%. With similar legislation introduced in 17 states, the findings from this study are important for consideration outside of California.

Modern contraceptive use among migrant and non-migrant women in Kenya.

BACKGROUND: Manifest socio-economic differences are a trigger for internal migration in many sub-Saharan settings including Kenya. An interplay of the social, political and economic factors often lead to internal migration. Internal migration potentially has significant consequences on an individual's economic growth and on access to health services, however, there has been little research on these dynamics. In Kenya, where regional differentials in population growth and poverty reduction continue to be priorities in the post MDG development agenda, understanding the relationships between contraceptive use and internal migration is highly relevant. METHODS: Using data from the 2008-09 Kenya Demographic and Health Survey (DHS), we analyze data from 5,905 women aged 15-49 years who reported being sexually active in the last 12 months prior to the survey. Bivariate and multivariate logistic regressions are fitted to predict correlates of contraceptive use in the presence of migration streams among other explanatory variables. RESULTS: Modern contraceptive use was significantly higher among women in all migration streams (non-migrant urban (OR = 2.8, p < 0.001), urban-urban (OR = 2.0, p < 0.001), urban-rural (OR = 2.0, p < 0.001), rural-urban (OR = 2.6, p < 0.001), rural-rural (OR = 1.7, p < 0.001), than non-migrant rural women. CONCLUSION: Women who internally migrate within Kenya, whether from rural to urban or between urban centres, were more likely to use modern contraception than non-migrant rural women. This phenomenon appears to be due to selection, adaption and disruption effects which are likely to promote use of modern contraceptives. Programmatically, the differentials in modern contraceptive use by the different migration streams should be considered when designing family planning programmes among migrant and non-migrant women.

Funding policies and postabortion long-acting reversible contraception: results from a cluster randomized trial.

BACKGROUND: Almost one-half of women having an abortion in the United States have had a previous procedure, which highlights a failure to provide adequate preventive care. Provision of intrauterine devices and implants, which have high upfront costs, can be uniquely challenging in the abortion care setting. OBJECTIVE: We conducted a study of a clinic-wide training intervention on long-acting reversible contraception and examined the effect of the intervention, insurance coverage, and funding policies on the use of long-acting contraceptives after an abortion. STUDY DESIGN: This subanalysis of a cluster, randomized trial examines data from the 648 patients who had undergone an abortion who were recruited from 17 reproductive health centers across the United States. The trial followed participants 18-25 years old who did not desire pregnancy for a year. We measured the effect of the intervention, health insurance, and funding policies on contraceptive outcomes, which included intrauterine device and implant counseling and selection at the abortion visit, with the use of logistic regression with generalized estimating equations for clustering. We used survival analysis to model the actual initiation of these methods over 1 year. RESULTS: Women who obtained abortion care at intervention sites were more likely to report intrauterine device and implant counseling (70% vs 41%; adjusted odds ratio, 3.83; 95% confidence interval, 2.37-6.19) and the selection of these methods (36% vs 21%; adjusted odds ratio, 2.11; 95% confidence interval, 1.39-3.21). However, the actual initiation of methods was similar between study arms (22/100 woman-years each; adjusted hazard ratio, 0.88; 95% confidence interval, 0.51-1.51). Health insurance and funding policies were important for the initiation of intrauterine devices and implants. Compared with uninsured women, those women with public health insurance had a far higher initiation rate (adjusted hazard ratio, 2.18; 95% confidence interval, 1.31-3.62). Women at sites that provide state Medicaid enrollees abortion coverage also had a higher initiation rate (adjusted hazard ratio, 1.73; 95% confidence interval, 1.04-2.88), as did those at sites with state mandates for private health insurance to cover contraception (adjusted hazard ratio, 1.80; 95% confidence interval, 1.06-3.07). Few of the women with private insurance used it to pay for the abortion (28%), but those who did initiated long-acting contraceptive methods at almost twice the rate as women who paid for it themselves or with donated funds (adjusted hazard ratio, 1.94; 95% confidence interval, 1.10-3.43). CONCLUSIONS: The clinic-wide training increased long-acting reversible contraceptive counseling and selection but did not change initiation for abortion patients. Long-acting method use after abortion was associated strongly with funding. Restrictions on the coverage of abortion and contraceptives in abortion settings prevent the initiation of desired long-acting methods.

Cost-Effectiveness of Introducing the SILCS Diaphragm in South Africa.

BACKGROUND: Though South Africa has high contraceptive use, unintended pregnancies are still widespread. The SILCS diaphragm could reduce the number of women with unmet need by introducing a discreet, woman-initiated, non-hormonal barrier method to the contraceptive method mix. METHODS: A decision model was built to estimate the impact and cost-effectiveness of the introduction of the SILCS diaphragm in Gauteng among women with unmet need for contraception in terms of unintended and mistimed pregnancies averted, assuming that the available contraceptives on the market were not a satisfying option for those women. Full costs were estimated both from a provider's and user's perspective, which also accounts for women's travel and opportunity cost of time, assuming a 5% uptake among women with unmet contraceptive need. The incremental cost-effectiveness ratio is computed at five and 10 years after introduction to allow for a distribution of fixed costs over time. A probabilistic sensitivity analysis was conducted to incorporate decision uncertainty. RESULTS: The introduction of the SILCS diaphragm in Gauteng could prevent an estimated 8,365 unintended pregnancies and 2,117 abortions over five years, at an annual estimated cost of US$55 per woman. This comes to a cost per pregnancy averted of US$153 and US$171 from a user's and provider's perspectives, respectively, with slightly lower unit costs at 10 years. Major cost drivers will be the price of the SILCS diaphragm and the contraceptive gel, given their large contribution to total costs (around 60%). CONCLUSIONS: The introduction of the SILCS diaphragm in the public sector is likely to provide protection for some women for whom current contraceptive technologies are not an option. However to realize its potential, targeting will be needed to reach women with unmet need and those with likely high adherence. Further analyses are needed among potential users to optimize the introduction strategy.

Impact of the federal contraceptive coverage guarantee on out-of-pocket payments for contraceptives: 2014 update.

BACKGROUND: The Affordable Care Act requires most private health plans to cover contraceptive methods, services and counseling, without any out-of-pocket costs to patients; that requirement took effect for millions of Americans in January 2013. STUDY DESIGN: Data for this study come from a subset of the 1842 women aged 18-39 years who responded to all four waves of a national longitudinal survey. This analysis focuses on the 892 women who had private health insurance and who used a prescription contraceptive method during any of the four study periods. Women were asked about the amount they paid out of pocket in an average month for their method of choice. RESULTS: Between fall 2012 and spring 2014, the proportion of privately insured women paying zero dollars out of pocket for oral contraceptives increased substantially, from 15% to 67%. Similar changes occurred among privately insured women using injectable contraception, the vaginal ring and the intrauterine device. CONCLUSIONS: The implementation of the federal contraceptive coverage requirement appears to have had a notable impact on the out-of-pocket costs paid by privately insured women, and that impact has increased over time. IMPLICATIONS: This study measures the out-of-pocket costs for women with private insurance prior to the federal contraceptive coverage requirement and after it took effect; in doing so, it highlights areas of progress in eliminating these costs.

Achieving cost-neutrality with long-acting reversible contraceptive methods.

OBJECTIVES: This analysis aimed to estimate the average annual cost of available reversible contraceptive methods in the United States. In line with literature suggesting long-acting reversible contraceptive (LARC) methods become increasingly cost-saving with extended duration of use, it aimed to also quantify minimum duration of use required for LARC methods to achieve cost-neutrality relative to other reversible contraceptive methods while taking into consideration discontinuation. STUDY DESIGN: A three-state economic model was developed to estimate relative costs of no method (chance), four short-acting reversible (SARC) methods (oral contraceptive, ring, patch and injection) and three LARC methods [implant, copper intrauterine device (IUD) and levonorgestrel intrauterine system (LNG-IUS) 20 mcg/24 h (total content 52 mg)]. The analysis was conducted over a 5-year time horizon in 1000 women aged 20-29 years. Method-specific failure and discontinuation rates were based on published literature. Costs associated with drug acquisition, administration and failure (defined as an unintended pregnancy) were considered. Key model outputs were annual average cost per method and minimum duration of LARC method usage to achieve cost-savings compared to SARC methods. RESULTS: The two least expensive methods were copper IUD ($304 per women, per year) and LNG-IUS 20 mcg/24 h ($308). Cost of SARC methods ranged between $432 (injection) and $730 (patch), per women, per year. A minimum of 2.1 years of LARC usage would result in cost-savings compared to SARC usage. CONCLUSIONS: This analysis finds that even if LARC methods are not used for their full durations of efficacy, they become cost-saving relative to SARC methods within 3 years of use. IMPLICATIONS: Previous economic arguments in support of using LARC methods have been criticized for not considering that LARC methods are not always used for their full duration of efficacy. This study calculated that cost-savings from LARC methods relative to SARC methods, with discontinuation rates considered, can be realized within 3 years.

Does switching contraceptive from oral to a patch or vaginal ring change the likelihood of timely prescription refill?

OBJECTIVE: This study evaluated contraceptive refill patterns of women insured commercially in the US who switched from oral contraceptives (OCs) to the patch or vaginal ring and assessed if switching contraceptive methods changes refill patterns. STUDY DESIGN: Women aged 15-44 with ≥2 patch or ring prescriptions and ≥2 OC prescriptions before the first patch/ring prescription were identified from the MarketScan® Commercial database (1/1/2002-6/30/2011). Refill patterns 1-year pre- and postindex date (first patch/ring prescription) were evaluated, and women were categorized as timely or delayed refillers on OCs and patch/ring. Regression modeling was used to investigate the association between refill patterns and contraceptive methods and switching effects on refill patterns. RESULTS: Of 17,814 women identified, 7901 switched to the patch, and 9913 switched to the ring. Among timely OC refillers, the percentage of timely refills decreased (patch: 95.6% to 79.4%, p<.001; ring: 96.5% to 74.3%, p<.001). However, among delayed OC refillers, the percentage of timely refills improved (patch: 47.9% to 72.2%, p<.001; ring: 50.4% to 64.0%, p<.001) during patch/ring use. Nonetheless, compared to timely OC refillers, women who were delayed OC refillers had 1.68-fold [95% confidence interval (CI): 1.52-1.84, p<.001] and 1.85-fold greater odds (CI: 1.69-2.02, p<.001) of being a delayed refiller while on the patch and ring, respectively. CONCLUSION: Switching to the patch or ring may improve refill behavior for women who have problems refilling OCs timely; however, the magnitude of the improvement may fail to improve ultimate contraceptive efficacy by simply switching to the patch or ring. IMPLICATIONS: The impact on timely refills of switching from OCs to either the patch or ring is complex and varies depending on the pattern of timely refills on OCs.

Changes in out-of-pocket payments for contraception by privately insured women during implementation of the federal contraceptive coverage requirement.

BACKGROUND: As part of the Affordable Care Act, a federal requirement for private health plans to cover contraceptive methods, services and counseling, without any out-of-pocket costs to patients, took effect for millions of Americans in January 2013. STUDY DESIGN: Data for this study come from a subset of the 3207 women aged 18-39 years who responded to two waves of a national longitudinal survey. This analysis focused on the 889 women who were using hormonal contraceptive methods in both the fall 2012 and spring 2013 waves and the 343 women who used the intrauterine device at either wave. Women were asked about the amount they paid out of pocket in an average month for their method of choice. RESULTS: Between Wave 1 and Wave 2, the proportion of privately insured women paying zero dollars out of pocket for oral contraceptives increased substantially, from 15% to 40%; by contrast, there was no significant change among publicly insured or uninsured women (whose coverage was not affected by the new federal requirement). Similar changes were seen among privately insured women using the vaginal ring. CONCLUSIONS: The initial implementation of the federal contraceptive coverage requirement appears to have had a notable impact on the out-of-pocket costs paid by privately insured women. Additional progress is likely as the requirement phases in to apply to more private plans, but with evidence that not all methods are being treated equally, policymakers should consider stepped-up oversight and enforcement of the provision. IMPLICATIONS: This study measures the out-of-pocket costs for women with private, public and no insurance prior to the federal contraceptive coverage requirement and after it took effect; in doing so, it highlights areas of progress in eliminating these costs and areas that need further progress.

Budget impact analysis of 8 hormonal contraceptive options.

OBJECTIVES: To develop a model comparing costs of 8 hormonal contraceptives and determine whether acquisition costs for implants and intrauterine devices (IUDs) were offset by decreased pregnancy-related costs over a 3-year time horizon from a managed care perspective. STUDY DESIGN: A model was developed to assess the budget impact of branded or generic oral contraceptives (OCs), quarterly intramuscular depot medroxyprogesterone, etonogestrel/ethinyl estradiol vaginal ring, etonogestrel implant, levonorgestrel IUD, norelgestromin/ethinyl estradiol transdermal contraceptive, and ethinyl estradiol/levonorgestrel extended-cycle OC. METHODS: Major variables included drug costs, typical use failure rates, discontinuation rates, and pregnancy costs. The base case assessed costs for 1000 women initiating each of the hormonal contraceptives. RESULTS: The etonogestrel implant and levonorgestrel IUD resulted in the fewest pregnancies, 63 and 85, respectively, and the least cost, $1.75 million and $2.0 million, respectively. In comparison, generic OC users accounted for a total of 243 pregnancies and $3.4 million in costs. At the end of year 1, costs for the etonogestrel implant ($800,471) and levonorgestrel IUD ($949,721) were already lower than those for generic OCs ($1,146,890). Sensitivity analysis showed that the cost of pregnancies, not product acquisition cost, was the primary cost driver. CONCLUSIONS: Higher initial acquisition costs for the etonogestrel implant and levonorgestrel IUD were offset within 1 year by lower contraceptive failure rates and consequent pregnancy costs. Thus, after accounting for typical use failure rates of contraceptive products, the etonogestrel implant and levonorgestrel IUD emerged as the least expensive hormonal contraceptives.

Contraceptive choices of overweight and obese women in a publically funded hospital: possible clinical implications.

BACKGROUND: Despite the growing obesity epidemic in the United States, family planning for overweight and obese women has been understudied. The aim of this study was to describe the contraception methods selected by normal weight, overweight and obese women. STUDY DESIGN: We retrospectively reviewed 7262 charts of women who underwent first trimester surgical termination of pregnancy at the John H. Stroger, Jr. Hospital of Cook County between January 1, 2008, and January 1, 2010. We analyzed the relationship between body mass index (BMI) and choice of contraceptive method, after adjusting for age, race, smoking and level of education. RESULTS: When compared to patients with BMI <25 kg/m², overweight (BMI 25-29.9 kg/m²) and obese patients (BMI ≥30 kg/m²) were more likely to select the intrauterine device (OR 1.3, 95% CI 1.28-1.32 for overweight; OR 1.6, 95% CI 1.59-1.61 for obese), contraceptive ring (OR 1.4, 95% CI 1.28-1.52 for overweight; OR 1.6, 95% CI 1.57-1.63 for obese) and tubal ligation (OR 1.5 95% CI 1.44-1.62 for overweight; OR 2.9, 95% CI 2.79-3.01 for obese). They were less likely to choose injectable contraception (OR 0.7, 95% CI 0.59-0.81 for overweight; OR 0.52, 95% CI 0.48-0.56 for obese). There was no relationship between BMI and choice of condoms, oral contraceptive pills and implantable methods. CONCLUSION: In our population, the contraceptive choices of overweight and obese women differed from those of normal weight women. These differences in contraceptive selection are important to recognize in light of the potential effect of BMI on the safety and efficacy of different contraceptive methods. Further research is needed to evaluate the contraceptive preferences, risks and benefits for overweight and obese women.

Preferences for new and existing contraceptive products.

New contraceptive methods provide greater choice in terms of effectiveness, management of side-effects, convenience and frequency of administration and flexibility, but make the decisions about contraception more complex. There are limited data on the factors that determine women's choices among these alternatives, to inform providers about the factors which are most important to women, or to predict uptake of new products. This paper reports on a choice experiment designed to elicit women's preferences in relation to prescribed contraception and to forecast the impact of the introduction of two new products into the Australian market. A generalised multinomial logit model is estimated and used in the simulation exercise. The model forecasts that the hormonal patch would be well received among women, achieving a greater market share than current non-pill products, but the vaginal ring would have limited appeal.

Advances in microbicide vaginal rings.

Vaginal ring devices capable of providing sustained/controlled release of incorporated actives are already marketed for steroidal contraception and estrogen replacement therapy. In recent years, there has been considerable interest in developing similar ring devices for the administration of microbicidal compounds to prevent vaginal HIV transmission. Intended to be worn continuously, such coitally independent microbicide rings are being developed to maintain effective vaginal microbicide concentrations over many weeks or months, thereby overcoming issues around timing of product application, user compliance and acceptability associated with more conventional semi-solid formulations. In this article, an overview of vaginal ring technologies is presented, followed by a review of recent advances and issues pertaining to their application for the delivery of HIV microbicides. This article forms part of a special supplement on presentations covering intravaginal rings, based on the symposium "Trends in Microbicide Formulations", held on 25 and 26 January 2010, Arlington, VA.