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Determinants of South African Women’s Demand for New Barrier Methods and their Distribution: Analysis of a Discrete Choice Experiment. Fern Terris-Prestholt, Lilani Kumaranayake, Catherine MacPhail, Helen Rees, Charlotte Watts London School of Hygiene & Tropical Medicine
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Determinants of South African Women’s Demand for New Barrier Methods and their Distribution: Analysis of a Discrete Choice Experiment Fern Terris-Prestholt, Lilani Kumaranayake, Catherine MacPhail, Helen Rees, Charlotte Watts London School of Hygiene & Tropical Medicine Reproductive Health and HIV Research Unit, Johannesburg IAEN August 1-2, 2008, Cuernavaca
Background 1 • Existing products for HIV prevention are failing to provide women with a means to protect themselves from HIV. • Male condom use remains subject to consent and active participation from men. • This study explores • women’s demand for new barrier methods for HIV prevention that women can initiate, and • how distribution and promotion strategies can facilitate their use.
Barrier methods for HIV prevention: • Existing methods • Male condoms • Female condoms (though not widely available) • Potential new methods • Microbicides • Diaphragm Male Condom Female Condom Microbicide applicator containing clear gel Diaphragm
Aims 1: product attributes • Policy-makers are concerned about substitution • This study explores how preferences for products vary by: • The product characteristics, • their effectiveness in preventing HIV • Women’s characteristics • women’s risk /need profiles and their ability to use male condoms
Aims 2: distribution & promotion strategies • Once an effective microbicide is found, it is critical to ensure women who need them can access them and introduce them into their relationships. • This study explores if: • new barrier methods need different distribution and promotion strategies from the existing methods • distribution strategies need to be tailored to reach different groups of women. Aim 1 & 2 → to inform the introduction and distribution strategy of new methods.
Data collection Survey • In three township communities in Johannesburg • 1017 sexually active adult women (18-45) • October 2005 • Questionnaire included: • demographics, • reproductive health histories, • directly elicited preferences, and • two discrete choice experiments
Physical attributes choice Neither option card 6 choice sets: Here are the products and this is what they do: Would you have used either of these products in your last sex act or would you have still done the same as you did the last time you had sex?
Distribution and promotion strategy choice Which of these ways would you prefer to collect your product? Other levels included: Chemist Supermarket From a shelf From a box or dispensing machine Pregnancy prevention Women’s empowerment 5 Rand 20 Rand
Not –change (C) condom or no condom Change Product profiles B A Estimation 1: physical attribute preferences • Main effects:Prob=f(Product, HIV effec, Preg effec, secrecy, price) • Plus • Interactions level 1 (Change, not-change): • Not change means use a male condom or use no condom (q104), • Having had difficulties using a male condom in the past (q103), • Cohabiting (q49) and Interactions 2 (between products profiles): • Product * used condom • Secrecy* had difficulties • Pregnancy effectiveness * cohabit • HIV effectiveness * self perceived risk (RISK) • HIV effectiveness * cohabit • Price * employment status • Nested Logit Structure:
Estimation 2: Distribution strategy preferences • MNL with interactions for: • new products (microbicide and diaphragm) • socio demographic characteristics (cohabiting, household SES, employment status)
What are women’s relative preferences for new barrier methods and how do these differ by women’s characteristics?
Probability of choosing a microbicide with different characteristics over a female condom or neither
What are women’s relative preferences for distribution strategies?
Challenges to analysis • Potential Biases: • ‘in the last sexact’: Many women responded based on best intentions in the possible future, rather than realistic and feasible option in last sexact. • Orthogonality: The trade off between a strictly orthogonal experimental design and realism: • less than efficient design • non convergence of more sophisticated models : e.g. RPL with correlations which would allow for identification of distribution strategy attributes. • HIV effectiveness very dominant attribute: 35% always chose alternative with highest HIV effectiveness • However, despite shortcomings appear to generate intuitive results.
Conclusions- physical attributes • Encouraging to see greater enthusiasm for switching to new products among women who are less able to protect themselves with existing methods: • Women who are not using condoms • Have had difficulties using condoms and • Are cohabiting. • Product effectiveness clearly played an important role in women’s choices • Hierarchical messages should work to help women choose the best options for them in their situations in this population.
Conclusions – distribution attributes • Outlet type had strongest impact on choices but did not vary much by product or women’s characteristics: • Do not need new infrastructure to distribute new products or reach different women • Advertising preferences do vary by product and women’s characteristics: • Advertising can be used to stimulate demand of different products by different women. • Suggests a social marketing approach may be successful.
Acknowledgements We thank • all the women of Ekurhuleni who participated in the survey and the formative qualitative research and • the enthusiastic research team who spent many an evening and weekend interviewing women. • This study was supported by funding from the DFID/MRC Microbicides Development Programme. UK Department for International Development (DFID). DFID supports policies, programmes and projects to promote international development. DFID provided funds for this study as part of that objective but the views and opinions expressed are those of the authors alone. • FTP, LK, HR, CW are members of the DFID Research Programme Consortium for Research and Capacity Building in Sexual and Reproductive Health and HIV in Developing Countries.