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Mixed methods in medical research

Mixed methods in medical research. Robert Pool Centre for International Health, Hospital Clinic, University of Barcelona London School of Hygiene & Tropical Medicine. THE BACKGROUND. Social science & medicine.

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Mixed methods in medical research

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  1. Mixed methods in medical research Robert Pool Centre for International Health, Hospital Clinic, University of Barcelona London School of Hygiene & Tropical Medicine

  2. THE BACKGROUND

  3. Social science & medicine • Increasing demand for qualitative social science in medical research programmes due to: • Realisation that illness is social as well as biological (adherence, acceptability, treatment seeking); the need to understand beliefs in order to change behaviour, fashionable • Better interdisciplinary communication • Consultation, collaboration, integration • Cooperation depends on suppressing/ignoring underlying differences

  4. Why mix methods? • To triangulate (get closer to the truth) • To develop (sequential use) • To complement (examine different aspects) • To broaden (discover wider context, new perspectives)

  5. THE PROJECT

  6. Microbicides Development Programme Objective: To determine the efficacy and safety of two concentrations of “PRO 2000/5 Gel” compared to placebo in preventing vaginally acquired HIV infection Primary outcome: acquisition of HIV infection Sample: 10,000 women Process: Feasibility  Pilot  Phase III

  7. Study sites

  8. Quantitative trial data • Women followed up for 12 months • Regular clinic visits (every 4 weeks) for: • condom & gel distribution • applicator returns • clinical exams • lab tests (STDs, HIV & pregnancy) • clinical & behavioural interviews (CRF)

  9. Issues Interpreting the trial result depends on the accuracy of sexual behaviour and adherence data  But self-reporting is unreliable

  10. Key questions • How do you know that participants understand the categories and questions in the way you intend? • How do you ask sexual behaviour questions across different cultures & vernaculars in a standardised way that enables meaningful comparison? • How do you know that your sexual behaviour data are accurate? • How do you know whether women have used the product (properly)?

  11. The social science • Qualitative social science integrated to address these issues • Random subsample (100 women at each site) • In-depth interviews with women & partners • Coital diaries • Focus group discussions • Ethnography

  12. Explore & clarify standard categories & questions • Almost all the central concepts in sexual behaviour research are ambiguous: • marriage, regular partner, casual partner • sex acts, condom use, etc. • Get emic meanings

  13. Interview • Comparison & probing inconsistencies Women Case Record Form Comparison Form IDI Nvivo T&T Coital Diary4 weeks before CRF Summaries Summaries • Interview • Comparison with women Male partners IDI Nvivo T&T FGDs Nvivo Women, community T&T Summaries THE TRIANGULATION PROCESS

  14. In-depth interview guide

  15. Consistency of CRF data • In 53% (254/482) some inconsistency • Mainly under-reporting of sex acts and over-reporting of gel and condom use on CRF

  16. Two main sets of reasons for the inaccuracies in the CRF: • The participant forgetting or not understanding. • The interviewer not asking, not listening, or not understanding • Confirmed by recording of CRF interviews • Training, memory aid, short recall periods, clarification of terminology

  17. Getting closer to the truth • You can get more accurate data on sexual behaviour (get closer to the truth) if you: • Clarify key concepts & categories • Need to identify and solve inconsistencies during the study • Ensure continuous feedback between different teams, methods and data sets • Engage in dialogue with participants

  18. THE ISSUES

  19. 1. How do you deal with inaccuracies once you’ve found them? • Unresolved inconsistencies (uncertainty)? • Resolved inconsistencies: • change the database? • extrapolate?

  20. 2. What do you do with key categories that remain ambiguous? Sex acts/rounds/days

  21. 3. How do you take into account the influence of the research process on the data? • On behaviour (condom use, practices) • On symptom perception (itching) • On how people categorise their experience (definition of sex acts)

  22. 4. How do you deal with “ethics”? The misplaced application of clinical trial ethics to social science research: • Flexibility of questions and “instruments” (open interviews, CD) • Flexibility of procedures (recording CRF interview, follow up women) • Observation

  23. Conclusion • Mixed models rather than mixed methods • Combine emic and etic approaches • Follow up and solve inconsistencies during the study • Reform “ethics” procedures

  24. How do we decide which data are most accurate?

  25. Opposing theoretical paradigms

  26. Different methods

  27. Also: • Continuation of the trial depends on informed consent • Success of product depends on acceptability

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