Pre-exposure Prophylaxis: A Miracle Drug or a Moral Hazard

Study Overview
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Brief Summary
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The investigators study the behavioral consequences of Pre-exposure Prophylaxis or PrEP on sexual health behaviors, sexual health outcomes, and partner selection preferences. The study collects observational, self-reported data on PrEP status, PrEP taking-history, PrEP adherence over the last 30 days, STD diagnosis history dating back to January 2015 up to December 2019, sexual health behaviors (e.g., positioning, number of lifetime/recent partners, condom adherence etc.), and various demographic characteristics. The survey finishes with a conjoint experiment which asks respondents to select between two potential partners, and follow-up question about each profiles. Potential partners' characteristics include recreational drug use and condom adherence. Recruitment is conducted via running an ad on Facebook in New York, London, Toronto and Sydney for comparative purposes, as these metro areas have varying levels of PrEP use and accessibility.

Detailed Description
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See statistical analysis plan.

Official Title
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Pre-exposure Prophylaxis: A Miracle Drug or a Moral Hazard

Conditions
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Syphilis, Chlamydia, Gonorrhea, Sexually Transmitted Diseases

Intervention / Treatment
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* Drug: PrEP


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 18 years or above living in the London, New York, Toronto or Sydney metro area self-reported sex at birth is male reported ever having sex with a male Exclusion Criteria: not meeting the inclusion criteria

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Respondents on PrEP<br>On PrEP status will be operationalized in multiple ways, and sensitivity analyses will be conducted using multiple definitions as a result of the self-reported nature of the study. Respondents on PrEP are respondents who reported that they are currently on PrEP Respondents on PrEP are respondents who reported to have ever been on PrEP When respondents are used as their own controls, years on PrEP will be those in which they reported to have been on PrEP for at lest 6 months, and PrEP initiation will be the first such year A comparison group will be constructed by matching on a variety of characteristics, when this method is applied. Most importantly, age, and STD testing frequency among others, which influence the likelihood of being on PrEP and via that avenue sexual practices, as well as the likelihood of detecting STDs (i.e., ascertainment bias). In other models adjustments will be made for these factors. | Drug: PrEP<br>* The investigators measure self-reported PrEP status as exposure, i.e., PrEP status is not confirmed via matched medical records or any other type of information directly collected form subjects.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Syphilis diagnosis | Self-reported diagnosis of syphilis | All diagnosis data is collected in a time-stamped fashion between January 2015 and December 2019; diagnosis is reported within the year, but not in a specific month/day | 
| Chlamydia diagnosis | Self-reported diagnosis of chlamydia | All diagnosis data is collected in a time-stamped fashion between January 2015 and December 2019; diagnosis is reported within the year, but not in a specific month/day | 
| Gonorrhea diagnosis | Self-reported diagnosis of gonorrhea | All diagnosis data is collected in a time-stamped fashion between January 2015 and December 2019; diagnosis is reported within the year, but not in a specific month/day | 
| Sexually transmitted diseases | Self-reported diagnosis of any STD | All diagnosis data is collected in a time-stamped fashion between January 2015 and December 2019; diagnosis is reported within the year, but not in a specific month/day | 
| Percent of time that condoms were used in sexual intercourse | Self-reported condom adherence | 12 months | 
| Number of ongoing sexual relationships | Self-reported number of concurrent sexual partners | Through study completion, approximately 2 months | 
| Number of sexual partners over the past 12 months | Self-reported number of sexual partners over the past 12 months | 12 months | 
| Selecting a potential date with many recent partners | The likelihood of selecting a potential date with 6 or more recent sexual partners in the conjoint experiment. Both AMCEs (average marginal component effects) and marginal means will be computed, see statistical analysis plan. As part of a conjoint experiment the investigators expose participants to a partner selection task. The attributes in the experiment and possible attribute values can be seen below: Race/ethnicity: White/Black/Asian Education: High school/Undergraduate degree/Graduate degree Number of sexual partners (past 3 months): 1/2-5 partners/6 or more Recreational drug use: Never/Sometimes/Often Seeking a...: Committed relationship/Casual relationship Use of condoms: Occasional/Frequent | Through study completion, approximately 2 months | 
| Selecting a potential date with frequent recreational drug use | The likelihood of selecting a potential date with frequent recreational drug use in the conjoint experiment. Both AMCEs (average marginal component effects) and marginal means will be computed, see statistical analysis plan. As part of a conjoint experiment the investigators expose participants to a partner selection task. The attributes in the experiment and possible attribute values can be seen below: Race/ethnicity: White/Black/Asian Education: High school/Undergraduate degree/Graduate degree Number of sexual partners (past 3 months): 1/2-5 partners/6 or more Recreational drug use: Never/Sometimes/Often Seeking a...: Committed relationship/Casual relationship Use of condoms: Occasional/Frequent | Through study completion, approximately 2 months | 
| Selecting a potential date with occasional condom adherence | The likelihood of selecting a potential date with occasional condom use in the conjoint experiment. Both AMCEs (average marginal component effects) and marginal means will be computed, see statistical analysis plan. As part of a conjoint experiment the investigators expose participants to a partner selection task. The attributes in the experiment and possible attribute values can be seen below: Race/ethnicity: White/Black/Asian Education: High school/Undergraduate degree/Graduate degree Number of sexual partners (past 3 months): 1/2-5 partners/6 or more Recreational drug use: Never/Sometimes/Often Seeking a...: Committed relationship/Casual relationship Use of condoms: Occasional/Frequent | Through study completion, approximately 2 months |