Background
Methods
Study design and data collection
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Personal and demographic information (e.g., level of education, sexual orientation, partnership status, country of origin)
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HIV testing history (month and year of last test)
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Knowledge about HIV (HIV epidemiology in Germany, transmission risk (“How do you assess the transmission risk in the respective situation?”) Response categories: High risk, intermediate risk, low risk, no risk, don’t know)
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Effects of anti-retroviral therapy (ART) on disease progression and infectiousness
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Sources of information about HIV (“Where did you get information about HIV?”)
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Condom use with different partners during the last six months (at the beginning of a new relationship, with primary partner, outside of primary relationship, sex with an acquaintance, sex with a person met online, anonymous sex, sex with an HIV-positive person). Response categories: always, mostly, rarely, never)
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Reasons for not using condoms at last unprotected intercourse (multiple response options e.g., ”I assumed that my partner was negative.” “We had a face-to-face conversation about serostatus before sex.”)
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Risk behaviour
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Sex during the last 6 months
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Number of sex partners within last 6 months
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Unsafe sex during the last 6 months (vaginal/anal/oral) (with persons you assumed were HIV-negative, with persons with unknown serostatus, with persons with HIV)
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History of sexually transmitted infections (STI) (syphilis, gonorrhoea, chlamydia, herpes, venereal warts)
Laboratory tests
Data analysis
Results
Study population
Cases (n = 105) | Controls (n = 105) | |
---|---|---|
Age
| ||
18-29 | 36% | 34% |
30-44 | 52% | 51% |
> 45 | 11% | 14% |
Level of education
| ||
Secondary school certificate or completed 8/9th grade | 17% | 15% |
Completed 10th grade | 30% | 27% |
High school graduate | 27% | 25% |
University degree | 23% | 33% |
Knowledge on HIV and HIV testing
High | Medium | Low | No risk | Don’t know | |
---|---|---|---|---|---|
Everyday contact
| |||||
Cases | 1% (n = 1) | 1% (n = 1) | 12% (n = 13) | 85% (n = 89) | 1% (n = 1) |
Controls | 4% (n = 4) | 1% (n = 1) | 23% (n = 24) | 71% (n = 75) | 1% (n = 1) |
Needle sharing
| |||||
Cases | 98% (n = 103) | 1% (n = 1) | 0% (n = 0) | 0% (n = 0) | 1% (n = 1) |
Controls | 98% (n = 103) | 1% (n = 1) | 0% (n = 0) | 0% (n = 0) | 1% (n = 1) |
Unprotected receptive anal sex with ejaculation
| |||||
Cases | 97% (n = 102) | 3% (n = 3) | 0% (n = 0) | 0% (n = 0) | 0% (n = 0) |
Controls | 94% (n = 99) | 5% (n = 5) | 0% (n = 0) | 0% (n = 0) | 1% (n = 1) |
Unprotected receptive anal sex without ejaculation
| |||||
Cases | 53% (n = 53) | 34% (n = 36) | 9% (n = 9) | 0% (n = 0) | 2% (n = 2) |
Controls | 51% (n = 54) | 35% (n = 35) | 11% (n = 12) | 1% (n = 1) | 1% (n = 1) |
Unprotected insertive anal sex
| |||||
Cases | 60% (n = 59) | 30% (n = 30) | 9% (n = 9) | 1% (n = 1) | 1% (n = 1) |
Controls | 58% (n = 60) | 30% (n = 29) | 8% (n = 8) | 2% (n = 2) | 2% (n = 2) |
Unprotected receptive oral sex without ejaculation
| |||||
Cases | 15% (n = 15) | 41% (n = 41) | 35% (n = 35) | 7% (n = 7) | 1% (n = 1) |
Controls | 10% (n = 10) | 23% (n = 22) | 57% (n = 55) | 8% (n = 8) | 2% (n = 2) |
Unprotected receptive oral sex with ejaculation
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Cases | 74% (n = 73) | 22% (n = 22) | 4% (n = 4) | 0% (n = 0) | 0% (n = 0) |
Controls | 56% (n = 54) | 34% (n = 33) | 9% (n = 9) | 0% (n = 0) | 1% (n = 1) |
Unprotected insertive oral sex
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Cases | 20% (n = 21) | 26% (n = 26) | 40% (n = 40) | 9% (n = 9) | 3% (n = 3) |
Controls | 14% (n = 15) | 25% (n = 26) | 45% (n = 44) | 13% (n = 13) | 3% (n = 5) |
Relationship status and duration of partnership
Cases | Controls | OR | p-value | Confidence interval (CI) | |
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Relationship status | |||||
Single
| 46% (n = 48) | 48% (n = 50) | 0.9 | 0.8 | 0.54–1.59 |
“monogamous” homosexual relationship
| 39% (n = 39) | 32% (n = 34) | 1.23 | 0.5 | 0.70–2.18 |
Non-monogamous homosexual relationship
| 2% (n = 2) | 7% (n = 7) | 0.3 | 0.09 | 0.06–1.34 |
“monogamous” heterosexual relationship
| 0% (n = 0) | 5% (n = 5) | 0.5 | 0.02 | 0.42–0.56 |
Non-monogamous heterosexual relationship
| 0% (n = 0) | 2% (n = 2) | 0.5 | 0.15 | 0.43–0.56 |
Duration of relationship
| |||||
< 6 months
| 50% (n = 22) | 20% (n = 10) | 3.9 | 0.003 | 1.57–9.70 |
6–12 months
| 11% (n = 5) | 8% (n = 4) | 1.4 | 0.6 | 0.36–5.75 |
> 12 months
| 39% (n = 17) | 71% (n = 35) | 0.25 | 0.001 | 0.11–0.60 |
Number of sex partners
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1 partner
| 18% (n = 14) | 18% (n = 14) | 1 | 0.95 | 0.44–2.17 |
2–20 partners
| 70% (n = 53) | 78% (n = 60) | 0.7 | 0.25 | 0.40–1.26 |
> 20 partners
| 12% (n = 9) | 4% (n = 3) | 3.3 | 0.07 | 0.86–12.8 |
Number of sex partners
STIs and unprotected anal intercourse (UAI)
Unprotected anal intercourse | |||||
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Cases | Controls | OR | p-value | CI | |
UAI with person with unknown HIV status
| 62% (n = 60) | 49% (n = 36) | 3.1 | 0.001 | 1.56–6.10 |
Insertive | 57% (n = 40) | 43% (n = 29) | 1.77 | 0.21 | 0.71–4.40 |
Receptive | 43% (n = 43) | 19% (n = 18) | 3.3 | 0.005 | 1.40–7.64 |
UAI with HIV positive person
| 18% (n = 17) | 12% (n = 11) | 0.6 | 0.21 | 0.26–1.35 |
Inconsistent condom use*
| |||||
Beginning of new relationship
| 44% (n = 33) | 34% (n = 25) | 1.5 | 0.2 | 0.79–2.99 |
During a relationship
| 77% (n = 33) | 71% (n = 25) | 1.3 | 0.4 | 0.66–2.84 |
Outside of primary relationship
| 42% (n = 43) | 30% (n = 27) | 2.3 | 0.012 | 1.20–4.30 |
With strangers
| 42% (n = 36) | 30% (n = 21) | 1.71 | 0.112 | 0.88–3.34 |
With HIV-positive partner
| 26% (n = 14) | 31% (n = 14) | 0.8 | 0.61 | 0.33–1.91 |
With acquaintances
| 62% (n = 49) | 43% (n = 31) | 2.2 | 0.016 | 1.16–4.24 |
With person met online
| 55% (n = 17) | 22% (n = 8) | 4.4 | 0.005 | 1.53–12.64 |
Being always safe**
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9% (n = 9) | 29% (n = 30) | 0.23 | < 0.000 | 0.11–0.52 |
Reasons for not using condoms during last unprotected (vaginal/anal) sex
Reasons for not using condoms | Cases (n = 90) | Controls (n = 84) | OR | p-value | CI |
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No condom available | 14% (n = 13) | 7% (n = 6) | 2.1 | 0.1 | 0.79–5.88 |
Would have disturbed the mood | 13% (n = 12) | 17% (n = 14) | 0.8 | 0.5 | 0.56–2.99 |
I thought there was no risk | 38% (n = 34) | 25% (n = 21) | 1.8 | 0.7 | 0.95–3.49 |
I hoped that nothing would happen | 32% (n = 28) | 25% (n = 21) | 1.4 | 0.4 | 0.28–1.44 |
Condom caused erection problems | 11% (n = 10) | 14% (n = 12) | 0.75 | 0.5 | 0.54–3.27 |
Assumed partner was negative. | 28% (n = 25) | 10% (n = 8) | 3.6 | 0.003 | 1.54–8.33 |
Convinced partner was negative** | 10% (n = 9) | 20% (n = 17) | 0.3 | 0.06 | 0.10–1.52 |
Talked with partner about serostatus before having sex** | 3% (n = 3) | 19% (n = 16) | 0.2 | 0.001 | 0.04–0.52 |
Condom use
Results from multivariate analysis
Variable | Odds ratio | p-value | CI |
---|---|---|---|
Age
| 0.98 | 0.539 | 0.96–1.07 |
Conversation about serostatus before sex
| 0.18 | 0.014 | 0.05–0.71 |
Unprotected sex with person with unknown serostatus
| 1.47 | 0.464 | 0.24–1.90 |
Insertive UAI with person with unknown serostatus
| 0.83 | 0.785 | 0.32–4.47 |
Receptive UAI with person with unknown serostatus
| 2.13 | 0.249 | 0.59–7.69 |
“Always safe”**
| 0.23 | 0.004 | 0.08–0.625 |