What do Dutch MSM think of preexposure prophylaxis to prevent HIV-infection? A cross-sectional study Janneke P. Bila, Udi Davidovicha, Wendy M. van der Veldta, Maria Prinsa,b, Henry J.C. de Vriesb,c,d, Gerard J.B. Sondere,f and Ineke G. Stoltea,b Objectives: Although preexposure prophylaxis (PrEP) is not registered in Europe, including the Netherlands, its approval and implementation are expected in the near future. We aimed to gain insight into PrEP awareness and the intention to use PrEP among MSM. Design: Cross-sectional study among 448 HIV-negative participants of the Amsterdam Cohort Study who completed a questionnaire concerning behavior and PrEP between 2012 and 2013. Methods: Characteristics, PrEP awareness, and intention to use PrEP were described and multinomial logistic regression was used to identify determinants of a medium and high intention to use PrEP. Results: PrEP awareness was 54%, but only 13% reported a high intention to use PrEP. High-risk MSM were more likely to have a medium [adjusted odds ratio (aOR): 1.78 (95% confidence interval [CI] 1.07–2.97)] or high [aOR: 3.92 (95% CI 1.68–9.15)] intention to use PrEP than low-risk MSM, as were MSM with higher perceptions of selfefficacy to use PrEP [high intention: aOR: 6.15 (95% CI 2.50–15.09)] and higher perceptions of relief due to PrEP [medium intention: aOR: 2.67 (95% CI 1.32–5.40); high intention: aOR: 14.87 (95% CI 5.98–37.01)] than MSM with lower perceptions. MSM with higher perceptions of shame about using PrEP [medium intention: aOR: 0.35 (95% CI 0.19–0.62); high intention: aOR: 0.22 (95% CI 0.07–0.71)] or with more worries about side-effects were less likely to have a high [aOR: 0.18 (95% CI 0.06– 0.54)] or medium [aOR: 0.29 (95% CI 0.12–0.72)] intention to use PrEP. Conclusion: The overall intention to use PrEP was relatively low, but higher among high-risk MSM. If PrEP implementation among high-risk MSM in the Netherlands becomes reality, PrEP awareness should be increased and psychosocial determinants that will influence uptake should be addressed. Copyright ß 2015 Wolters Kluwer Health, Inc. All rights reserved.
AIDS 2015, 29:955–964 Keywords: HIV, HIV prevention, MSM, preexposure prophylaxis, sexual risk behavior
a
Department of Infectious Diseases Research and Prevention, Public Health Service Amsterdam, bDepartment of Infectious Diseases, Center for Infection and Immunology Amsterdam (CINIMA), Academic Medical Center (AMC), University of Amsterdam, cSTI Outpatient Clinic, Public Health Service Amsterdam, dDepartment of Dermatology, Academic Medical Center (AMC), University of Amsterdam, eDepartment of Infectious Diseases, Public Health Service of Amsterdam, and fDivision of Infectious Diseases, Department of Internal Medicine, Academic Medical Center (AMC), University of Amsterdam, Amsterdam, The Netherlands. Correspondence to Janneke P. Bil, Department of Infectious Diseases Research and Prevention, Public Health Service Amsterdam, PO box 2200, 1000 CE Amsterdam, the Netherlands. Tel: +31 205555569; e-mail: [email protected] Received: 30 October 2014; revised: 20 February 2015; accepted: 25 February 2015. DOI:10.1097/QAD.0000000000000639
ISSN 0269-9370 Copyright Q 2015 Wolters Kluwer Health, Inc. All rights reserved.
Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
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Introduction Despite widespread implementation of behavioral interventions to prevent transmission of HIVand high coverage of antiretroviral therapy (ART) among HIV-infected MSM, HIV continues to spread among this group in the Netherlands and other countries [1]. Annually, about 1100 newly diagnosed HIV infections are registered in the Netherlands, of which 700–750 are among MSM, whose HIV incidence has fluctuated between 2.0 and 0.6/100 person-years from 2009 through 2012 [2,3]. Preexposure prophylaxis (PrEP) is a new biomedical approach that offers HIV-negative individuals a regime of lower-intensity ART to reduce their risk of HIV infection. In 2010, the multinational preexposure prophylaxis initiative (iPrEX) study showed a 44% reduction in HIV acquisition in MSM receiving daily PrEP [tenofovir disoproxyl fumarate (TDF) and emtricitabine (FTC)] compared with placebo controls, and a 92% reduction among adherent MSM (i.e. with detectable drug levels) [4]. Although drug adherence, side-effects, and possible drug-resistance are serious challenges, the Food and Drug Administration in the United States approved PrEP in May 2012 for uninfected individuals who are at high risk of HIV infection and who engage in sexual activity with HIV-infected partners [5]. Although PrEP is not yet registered in Europe, including the Netherlands, its approval and implementation are expected in the near future. Knowledge and willingness to use PrEP among those at increased risk for HIV infection, such as MSM, are necessary for PrEP uptake and will determine the success of PrEP implementation. However, knowledge and willingness to use PrEP have not been studied yet in the Netherlands. This study aims to gain insight into PrEP awareness, the intention to use PrEP, and to identify sociodemographic and psychosocial determinants of a higher intention to use PrEP among Dutch MSM. We hypothesized that MSM at higher risk for HIV infection will be more aware of PrEP and will have a higher intention to use PrEP than MSM at lower risk. Although behavioral intentions do not absolutely predict actual PrEP uptake, they provide a good indication of the general willingness to use PrEP [6,7]. In this study, we additionally explored the anticipated condom use if men would decide to use PrEP because PrEP use might affect sexual behavior. Finally, we explored the influence of PrEP characteristics (cost, duration, and efficacy) on the willingness to use PrEP.
Methods Study population and procedures The Amsterdam Cohort Study (ACS) among MSM is an open, prospective cohort study initiated in 1984 aiming
to investigate the epidemiology, natural history, and pathogenesis of HIV, and to evaluate the effect of interventions [8,9]. Participants visit the Public Health Service Amsterdam every 6 months to complete selfadministrated questionnaires on sexual behavior, give blood for HIV testing (two ELISAs: AxSYM; Abbot Laboratories, North Chicago, Illinois, USA; Vironostika, Organon Teknika, Boxtel, The Netherlands), storage, and since 2008 also sexually transmitted infection (STI) screening (gonorrhea: nucleic acid amplification test on pharyngeal/anal swabs and urine: Gen-Probe Aptima Combo 2 Assay, Gen-Probe Incorporated, San Diego, California, USA). The ACS was approved by the Medical Ethical Committee of the Amsterdam Medical Center of Amsterdam, the Netherlands. For our cross-sectional study, data were collected during one 6 monthly data wave (June 2012–January 2013), when the ACS questionnaire was augmented with items about PrEP awareness and intention to use PrEP. Before answering questions about PrEP, participants were given the following written information: ‘Preexposure prophylaxis (PrEP) refers to the possibility for HIV-negative individuals to take anti-HIV drugs daily for an extended period of time to reduce the risk of HIV infection. The efficacy of PrEP is still being tested, and therefore PrEP is not (yet) available in the Netherlands’. Participants were given no information about PrEP efficacy, side-effects, costs, or duration. We included HIV-negative MSM who completed questions related to PrEP awareness and the intention to use PrEP.
Variables Sociodemographic characteristics Characteristics included age, nationality (Dutch/nonDutch), educational level (no college degree/at least college degree), and net monthly income level (low: 1700 Euro/medium: 1701–2950 Euro/high: 2951 Euro). Sexual behavior Men were categorized into HIV-risk infection group based on three risk factors for HIV seroconversion identified in previous research within the ACS [3]: having receptive condomless anal sex (CAS) with casual partners; having more than five casual partners in the preceding 6 months; diagnosed gonorrhea (urethral or rectal) at ACS visit. Men reporting at least one of these factors were defined as high-risk (Hr-MSM). Those reporting none of these factors were defined as low-risk (Lr-MSM).
CAS was defined as not or not always using a condom during anal sex; condom use was measured on a fivepoint scale ranging from ‘always’ to ‘never’. Two questions concerning steady partners were combined and categorized into having no steady partner, an HIVnegative steady partner, and a steady partner with positive or unknown HIV status.
Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
Preexposure prophylaxis in the Netherlands Bil et al. Awareness of and beliefs about preexposure prophylaxis We asked participants if they had ever heard of PrEP. Those aware of PrEP were asked about their chief source of knowledge (multiple-choice question). All participants (aware or unaware of PrEP) were asked about their beliefs about PrEP; efficacy (measured on a 4-point scale ranging from ‘PrEP can reduce the risk of HIV by 100%’ to ‘PrEP does not reduce the risk of HIV’); efficacy in combination with always, sometimes, or never using condoms (measured in three questions, all on a 7-point scale ranging from ‘no protection’ to ‘100% protection’); and side-effects (’rare’, ‘sometimes reported’, ‘appear frequently’, ‘knowledge is still scarce’). Intention to use preexposure prophylaxis The intention to use PrEP was assessed in all MSM (aware or unaware of PrEP) by two questions: ‘How likely are you to use PrEP if it becomes available in the Netherlands?’ and ‘Are you planning on using PrEP if it becomes available in the Netherlands?’ (both measured on a 7-point scale from ‘very unlikely’ to ‘very likely’). Given their acceptable correlation (Spearman’s rho 0.7; P < 0.001), the mean score of these items was used to represent the ‘intention to use PrEP’. Intention to use PrEP was categorized based on tertiles, into low (score < 2), medium (score 2–4), and high intention (score >4). Psychosocial determinants concerning preexposure prophylaxis The questionnaire included 13 items measuring psychosocial determinants concerning PrEP. For analyses, items were combined if they measured the same psychosocial determinant and had acceptable reliability (>3 items: Cronbach’s a 0.6). This resulted in eight determinants. Three concerned perceived self-efficacy: to use PrEP, to use PrEP every day on time, and to pay for PrEP (four items: s50, s100, s500, or s1000 per month, Cronbach’s a 0.9). The other five concerned perceived emotional impact of PrEP: whether men would feel worried about PrEP side-effects, worried about PrEP efficacy, less worried about getting HIV-infected when using PrEP, ashamed about using PrEP, and relieved when using PrEP (three items: feeling liberated, relieved, and hopeful, Cronbach’s a 0.9). All items were measured on a seven-point scale (ranging from ‘very difficult’ to ‘very easy’ or ‘totally disagree’ to ‘totally agree’).
As determinants were not normally distributed and a linear association was absent, they were dichotomized at the logical mid-point of a seven-point scale, with scores 4 or less representing low perceptions and scores more than 4 representing higher perceptions. Anticipated condom use Anticipated condom use was measured by the item: ‘I would be less likely to use condoms when using PrEP’
(7-point scale ranging from ‘totally disagree’ to ‘totally agree’). As earlier, responses were dichotomized into ‘no anticipated decrease in condom use while using PrEP’ (score 4) or ‘anticipated decrease in condom use while using PrEP’ (score >4). Perceived self-efficacy to use condoms while using PrEP was measured with one item: ‘How easy would it be to continue using condoms while using PrEP?’ (7-point scale ranging from ‘very easy’ to ‘very difficult’), which was dichotomized into ‘high perceived self-efficacy’ (score 4) and ‘low perceived self-efficacy’ (score >4). Influence of preexposure prophylaxis characteristics among MSM with high intention to use preexposure prophylaxis We assessed willingness to use PrEP at various levels of monthly cost (s50, s100, s500, s1000), for different duration of usage (3, 6 months, 1, 5, and 10 years), and when less than 100% efficacy (two combined items because they had acceptable correlation: Spearman rho 0.6; P < 0.001). Willingness was analyzed for participants with a high intention to use PrEP only. Items were measured on a seven-point scale ranging from ‘definitely not willing’ to ‘very willing’. Responses were dichotomized at mid-point into ‘unwilling’ (score 4) and ‘willing’ (score >4).
Statistical analyses First, we described sociodemographic characteristics, sexual (risk) behavior, and PrEP awareness. We compared distributions of characteristics and potential determinants between Hr-MSM and Lr-MSM, using chi-square tests for categorical variables and Mann–Whitney U tests for all, not normally distributed, continuous variables. Second, we performed multinomial logistic regression analyses to explore whether sociodemographic characteristics, sexual (risk) behavior, and psychosocial determinants were associated with a medium or high intention (reference is low intention) to use PrEP. Due to the many variables, the multivariate model was built in three steps: sociodemographic characteristics and sexual (risk) behavior associated with a higher intention (overall P < 0.10) in univariate analysis were included in a multivariate model; psychosocial determinants associated with a higher intention (overall P < 0.10) in univariate analyses were included in a separate multivariate model; variables associated with a higher intention to use PrEP (overall P < 0.10) in one of the two multivariate models were included in a final multivariate model, and considered statistically significant if the overall P value was less than 0.05. In sensitivity analyses, the three HIV risk factors defining Hr-MSM (number of casual partners, receptive CAS with casual partners, gonorrhea diagnosis) were included separately in the final model. Third, we described anticipated condom use when using PrEP and employed chi-square tests to evaluate whether
Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
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results differed among subgroups (MSM currently vs. not currently engaging in CAS and MSM with a low vs. medium vs. high intention to use PrEP). Fourth, we described the influence of PrEP characteristics on the willingness to use PrEP among MSM with initially high intention to use PrEP. Analyses were performed using STATA Intercooled 13.1 (STATA Corporation, College Station, Texas, USA).
Results Participant characteristics From June 2012 to January 2013, 466 HIV-negative MSM had a 6 monthly ACS visit, of whom 448 (96%) completed PrEP questions and were included in this study. Their median age was 40 years [interquartile range (IQR) 35–45] (Table 1), most were Dutch (92%; 404/ 440), college graduates (90%; 404/447), and had a medium income (41%; 163/397). In the preceding 6 months, men reported a median of 4 (IQR 0–11) casual partners and 64% (276/433) had a steady partner. Over half of participants (59%; 261/444) reported CAS in the preceding 6 months and 3% (11/434) were diagnosed with gonorrhea at their ACS visit. Overall, 47% (202/ 430) were defined as Hr-MSM, of whom 89% (179/201) had more than five casual partners; 30% (61/202) had receptive CAS with casual partners, and 6% (11/198) were diagnosed with gonorrhea. Hr-MSM were significantly older [median age 41 (IQR 36–45) vs. 39 years (IQR 34–43)] and less likely to have a steady partner (51 vs. 24%) than Lr-MSM. Awareness of and beliefs about preexposure prophylaxis Of the 448 participants, 54% (n ¼ 242) were aware of PrEP (Table 1). Hr-MSM were more likely to be aware of PrEP than Lr-MSM (60 vs. 50%, respectively; P ¼ 0.031). Almost half of MSM aware of PrEP (42%; 102/241) reported the ACS as their chief source of knowledge followed by the internet and a professional healthcare provider (both 10%). About one-third believed PrEP could significantly reduce the risk of HIV (38%; 168/448) and a comparable proportion was unaware of PrEP efficacy (38%; 169/ 448). A majority was unaware of PrEP side-effects (66%; 294/448), but of 154 men that were aware, 58% believed that side-effects appeared frequently. Beliefs about sideeffects did not differ between Hr-MSM and Lr-MSM. MSM believed that PrEP had a high protective effect if always combined with condoms [mean 5.5 (standard deviation [SD] 1.7)], but only medium effective if sometimes [mean 3.8 (SD 1.4)] or never [mean 3.2 (1.5)] combined with condoms. For the last two items,
Hr-MSM perceived PrEP to more effective than LrMSM (P 0.001).
Determinants of intention to use preexposure prophylaxis Of all participants, 27% (n ¼ 120) had a low intention, 60% (n ¼ 270) a medium intention, and 13% (n ¼ 58) a high intention to use PrEP. Multivariate multinomial regression analyses including sociodemographics and sexual (risk) behavior variables with a univariate P value less than 0.10 (Table 2) showed that Hr-MSM and MSM with no steady partner or with a steady partner with a positive or unknown HIV status were more likely to have higher intentions to use PrEP. Educational level became nonsignificant. In multivariate analyses including psychosocial determinants with a univariate P value less than 0.10 (Table 3), all perceptions, except those concerning worries about PrEP efficacy and about getting HIV-infected when using PrEP, were associated with higher intentions to use PrEP. In the final combined multivariate model (Table 4), including all variables with a P value less than 0.10 from tables 2 and 3, Hr-MSM were more likely to have a medium [adjusted odds ratio (aOR) 1.78 (95% confidence interval [CI] 1.07–2.97)] or high intention to use PrEP [aOR 3.92 (95% CI 1.68–9.15)] than Lr-MSM. Sensitivity analyses found that all three separate HIV risk factors defining Hr-MSM (number of casual partners, receptive CAS with casual partners, gonorrhea diagnosis) were associated with higher intentions to use PrEP, but only the number of casual partners was statistically significant (P ¼ 0.020, data not shown). The effect of steady partner decreased and became statistically nonsignificant. MSM that were aware of PrEP were also more likely to have a high intention to use PrEP [aOR 2.41 (95% CI 1.07–5.45)] than those unaware, but the overall effect on intention was not statistically significant (P ¼ 0.105). MSM with high perceived self-efficacy to use PrEP were more likely to have a high intention to use PrEP [aOR 6.15 (95% CI 2.50–15.09)] than MSM with low perceived self-efficacy (overall P < 0.001). Furthermore, having higher perceptions of relief when using PrEP was associated with a medium [aOR 2.67 (95% CI 1.32–5.40)] and high intention to use PrEP [aOR 14.87 (95% CI 5.98–37.01)]. Feelings of shame about using PrEP decreased the intention to use PrEP [aOR 0.35 (95% CI 0.19–0.62) for medium and aOR 0.22 (95% CI 0.07–0.71) for high intention], as did worries about sideeffects of PrEP [aOR 0.29 (95% CI 0.12–0.72) and aOR 0.18 (95% CI 0.06–0.54), respectively].
Anticipated condom use About one-third of participants (39%; 174/447) anticipated a decrease in their condom use during anal sex while using PrEP (Table 5). In addition, about one-quarter (26%; 115/446) had low perceived self-efficacy to use condoms
Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
Preexposure prophylaxis in the Netherlands Bil et al. Table 1. Characteristics, preexposure prophylaxis awareness and beliefs about preexposure prophylaxis according to sexual risk behavior among 448 HIV-negative MSM participating in the Amsterdam Cohort Studies from June 2012 through January 2013, Amsterdam, the Netherlands. Risk of HIV infectiona Total (N ¼ 448) n
Lr-MSM (n ¼ 228)
%
Age (years) (Median [IQR]) 40 [34–35] Nationality Non-Dutch 36 8.2 Dutch 404 91.8 Educational level No college degree 43 9.6 At least college degree 404 90.4 Monthly income level Low (2950 Euro) 120 30.2 Steady partner None 157 36.3 HIV-negative 214 49.4 Positive or unknown HIV status 62 14.3 Number of casual sexual partners in the preceding 6 months (Median [IQR]) 4 [0–11] CAS in the preceding 6 months (insertive and/or receptive) Currently not engaging in CAS 183 41.2 CAS with steady partner 151 34.0 CAS with casual partner 82 18.5 CAS with steady and casual partner 28 6.3 Gonorrhea at ACS visit No 423 97.5 Yes 11 2.5 Awareness of PrEP Never heard of PrEP 206 46.0 Ever heard of PrEP 242 54.0 e Chief source of knowledge about PrEP Internet 23 9.5 HIV-patient organization 8 3.3 Professional healthcare provider 23 9.5 ACS 102 42.3 Newspaper/TV 17 7.1 Friends/family 21 8.7 Other 16 6.6 Unknown 31 12.9 Beliefs about efficacy of PrEP PrEP can reduce the risk of HIV by 100% 1 0.2 PrEP can significantly reduce the risk of HIV 168 37.5 PrEP could slightly reduce the risk of HIV 103 22.9 PrEP does not reduce the risk of HIV 7 1.6 I do not know 169 37.7 Beliefs about side-effects of PrEP Side-effects are rare 2 0.5 Side-effects are sometimes reported 46 10.3 Side-effects appear frequently 70 15.6 Knowledge about side-effects is still scarce 36 8.0 I do not know 294 65.6 Beliefs about efficacy of PrEP (mean [SD]) (1. no protection - 7. 100% protection for HIV) Efficacy when you always use condoms during anal sex 5.5 [1.7] Efficacy when you sometimes use condoms during anal sex 3.8 [1.4] Efficacy when you never use condoms during anal sex 3.2 [1.5]
Hr-MSM (n ¼ 202)
n
%
n
%
P value
39
[34–43]
41
[36–45]
0.006b
21 204
9.3 90.7
15 183
7.6 92.4
0.518c
23 205
10.1 89.9
18 184
8.9 91.1
0.678c
53 90 61
26.0 44.1 29.9
57 65 55
32.2 36.7 31.1
0.274c
53 132 32
24.4 60.8 14.7
101 72 25
51.0 36.4 12.6
2950 Euro)
27 44 34
Steady partner None HIV-negative Positive or unknown HIV status HIV-risk behavior group Lr-MSM Hr-MSM
High intention to use PrEP (n ¼ 58) aOR (95% CI)
OR (95% CI)
aOR (95% CI)
Overall P valuea
1b 0.35 (0.12–1.00)
0.100
n
%
1 0.98 (0.58–1.67) 0.96 (0.57–1.62)
15 22 21
10.0 14.8 14.1
1 1.54 (0.70–3.40) 1.44 (0.65–3.17)
52.8 61.4
1 1.09 (0.48–2.48)
8 48
22.2 11.9
1 0.50 (0.18–1.38)
25 245
58.1 60.6
1 0.61 (0.26–1.46)
11 47
25.6 11.6
1b 0.27 (0.10–0.73)
23.7 27.0 28.3
65 95 78
57.0 58.3 65.0
1 0.90 (0.51–1.59) 0.95 (0.52–1.74)
22 24 8
19.3 14.7 6.7
1b 0.67 (0.32–1.42) 0.29 (0.11–0.75)
30 70 14
19.1 32.7 22.6
100 128 34
63.7 59.8 54.8
1.82 (1.10–3.01) 1b 1.33 (0.67–2.64)
1.50 (0.88–2.55) 1 1.29 (0.61–2.70)
27 16 14
17.2 7.5 22.6
3.94 (1.86–8.35) 2.22 (0.99–4.95) 1d 1b 4.38 (1.75–10.96) 3.74 (1.40–9.96)
73 40
32.3 19.6
133 129
58.8 63.2
1b 1.72 (1.09–2.71)
1b 1.63 (1.01–2.66)
20 35
8.8 17.2
1c 3.19 (1.63–6.25)
1 0.75 (0.30–1.83)
1c 2.78 (1.36–5.70)
0.044
0.016
aOR, adjusted odds ratio; CI, confidence interval; Hr-MSM, men having sex with men at high risk of HIV-infection; Lr-MSM, men having sex with men at low risk of HIV-infection; OR, odds ratio; PrEP, preexposure prophylaxis. a Overall P value of higher intention in adjusted analyses. b P < 0.05. c P < 0.01. d P < 0.001.
Influence of preexposure prophylaxis characteristics among MSM with a high intention to use preexposure prophylaxis In total, 58 men had a high intention to use PrEP, of whom a majority was willing to take PrEP daily for 3 (88%), 6 months (85%), or 1 year (74%), and about half even for 5 (59%) or 10 years (52%). There were 32 MSM (55%) who were willing to use PrEP when having to pay. Willingness to use PrEP decreased with increasing costs: 55% would take PrEP at s50 per month, but only 3% remained willing at s1000 per month. Finally, 23 MSM (40%) remained willing to take PrEP even if it were less than 100% effective.
Discussion This is the first study focusing on awareness of PrEP and intention to use PrEP among Dutch MSM. About half of the MSM in the ACS were aware of PrEP; most MSM were unaware of PrEP side-effects, and only 13% had a high intention to use PrEP. High-risk sexual behavior was
independently associated with a higher intention, as were psychosocial determinants such as high perceived selfefficacy and high perceptions of relief when using PrEP. Feelings of shame about using PrEP, worries about sideeffects, and PrEP characteristics, such as increasing costs and perceived insufficient efficacy were found to decrease the intention to use PrEP. Compared with other studies from high-income countries, where proportions of a high intention to use PrEP ranged between 28 and 74% [10–18], our proportion of 13% was relatively low. These differences are unlikely to be explained by differences in behavioral characteristics as study populations seem similar. This finding suggests that acceptability of PrEP might currently be lower in the Netherlands than elsewhere, possibly explained by differences in PrEP knowledge. Previous cost-effectiveness studies show that PrEP is most likely to be beneficial when targeting Hr-MSM, but the effect depends highly on uptake, adherence, frequency of monitoring, and duration of PrEP use [19–23]. We found
Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
Preexposure prophylaxis in the Netherlands Bil et al. Table 3. Multinomial logistic regression analysis of psychosocial determinants associated with the intention to use preexposure prophylaxis among 448 HIV-negative MSM participating in the Amsterdam Cohort Studies from June 2012 through January 2013, Amsterdam, The Netherlands. Low intention to use PrEP (Ref.) n ¼ 120
n
%
PrEP awareness (aware vs. unaware) Aware of PrEP 55 22.7 Perceived self-efficacy (high vs. low) High perceived self-efficacy to 17 18.7 use PrEP High perceived self-efficacy to 34 23.9a use PrEP every day on time High perceived self-efficacy to pay 18 24.0a for PrEP (50–1000 Euro/month) Perceived emotional impact of PrEP (high vs. low) High perception of worry about 112 30.3a PrEP side-effects High perception of worry about 107 30.0a PrEP efficacy High perception of decreased 46 25.0a worry about getting HIV-infected when using PrEP High perception of shame about 35 44.3a using PrEP High perception of relief when using PrEP 15 13.3a
Medium intention to use PrEP n ¼ 270
n
%
147 60.7 b
46
50.5
87 47
High intention to use PrEP n ¼ 58
OR (95% CI)
aOR (95% CI)
1.41 (0.92–2.17)
1.39 (0.88–2.18)
1.27 (0.69–2.32)
n
1.06 (0.57–1.99)
%
40 16.5
OR (95% CI)
aOR (95% CI)
2.63 (1.36–5.09)e
2.71 (1.27–5.77)d
0.035
e
AIDS 2015, 29:955–964 Keywords: HIV, HIV prevention, MSM, preexposure prophylaxis, sexual risk behavior
a
Department of Infectious Diseases Research and Prevention, Public Health Service Amsterdam, bDepartment of Infectious Diseases, Center for Infection and Immunology Amsterdam (CINIMA), Academic Medical Center (AMC), University of Amsterdam, cSTI Outpatient Clinic, Public Health Service Amsterdam, dDepartment of Dermatology, Academic Medical Center (AMC), University of Amsterdam, eDepartment of Infectious Diseases, Public Health Service of Amsterdam, and fDivision of Infectious Diseases, Department of Internal Medicine, Academic Medical Center (AMC), University of Amsterdam, Amsterdam, The Netherlands. Correspondence to Janneke P. Bil, Department of Infectious Diseases Research and Prevention, Public Health Service Amsterdam, PO box 2200, 1000 CE Amsterdam, the Netherlands. Tel: +31 205555569; e-mail: [email protected] Received: 30 October 2014; revised: 20 February 2015; accepted: 25 February 2015. DOI:10.1097/QAD.0000000000000639
ISSN 0269-9370 Copyright Q 2015 Wolters Kluwer Health, Inc. All rights reserved.
Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
955
956
AIDS
2015, Vol 29 No 8
Introduction Despite widespread implementation of behavioral interventions to prevent transmission of HIVand high coverage of antiretroviral therapy (ART) among HIV-infected MSM, HIV continues to spread among this group in the Netherlands and other countries [1]. Annually, about 1100 newly diagnosed HIV infections are registered in the Netherlands, of which 700–750 are among MSM, whose HIV incidence has fluctuated between 2.0 and 0.6/100 person-years from 2009 through 2012 [2,3]. Preexposure prophylaxis (PrEP) is a new biomedical approach that offers HIV-negative individuals a regime of lower-intensity ART to reduce their risk of HIV infection. In 2010, the multinational preexposure prophylaxis initiative (iPrEX) study showed a 44% reduction in HIV acquisition in MSM receiving daily PrEP [tenofovir disoproxyl fumarate (TDF) and emtricitabine (FTC)] compared with placebo controls, and a 92% reduction among adherent MSM (i.e. with detectable drug levels) [4]. Although drug adherence, side-effects, and possible drug-resistance are serious challenges, the Food and Drug Administration in the United States approved PrEP in May 2012 for uninfected individuals who are at high risk of HIV infection and who engage in sexual activity with HIV-infected partners [5]. Although PrEP is not yet registered in Europe, including the Netherlands, its approval and implementation are expected in the near future. Knowledge and willingness to use PrEP among those at increased risk for HIV infection, such as MSM, are necessary for PrEP uptake and will determine the success of PrEP implementation. However, knowledge and willingness to use PrEP have not been studied yet in the Netherlands. This study aims to gain insight into PrEP awareness, the intention to use PrEP, and to identify sociodemographic and psychosocial determinants of a higher intention to use PrEP among Dutch MSM. We hypothesized that MSM at higher risk for HIV infection will be more aware of PrEP and will have a higher intention to use PrEP than MSM at lower risk. Although behavioral intentions do not absolutely predict actual PrEP uptake, they provide a good indication of the general willingness to use PrEP [6,7]. In this study, we additionally explored the anticipated condom use if men would decide to use PrEP because PrEP use might affect sexual behavior. Finally, we explored the influence of PrEP characteristics (cost, duration, and efficacy) on the willingness to use PrEP.
Methods Study population and procedures The Amsterdam Cohort Study (ACS) among MSM is an open, prospective cohort study initiated in 1984 aiming
to investigate the epidemiology, natural history, and pathogenesis of HIV, and to evaluate the effect of interventions [8,9]. Participants visit the Public Health Service Amsterdam every 6 months to complete selfadministrated questionnaires on sexual behavior, give blood for HIV testing (two ELISAs: AxSYM; Abbot Laboratories, North Chicago, Illinois, USA; Vironostika, Organon Teknika, Boxtel, The Netherlands), storage, and since 2008 also sexually transmitted infection (STI) screening (gonorrhea: nucleic acid amplification test on pharyngeal/anal swabs and urine: Gen-Probe Aptima Combo 2 Assay, Gen-Probe Incorporated, San Diego, California, USA). The ACS was approved by the Medical Ethical Committee of the Amsterdam Medical Center of Amsterdam, the Netherlands. For our cross-sectional study, data were collected during one 6 monthly data wave (June 2012–January 2013), when the ACS questionnaire was augmented with items about PrEP awareness and intention to use PrEP. Before answering questions about PrEP, participants were given the following written information: ‘Preexposure prophylaxis (PrEP) refers to the possibility for HIV-negative individuals to take anti-HIV drugs daily for an extended period of time to reduce the risk of HIV infection. The efficacy of PrEP is still being tested, and therefore PrEP is not (yet) available in the Netherlands’. Participants were given no information about PrEP efficacy, side-effects, costs, or duration. We included HIV-negative MSM who completed questions related to PrEP awareness and the intention to use PrEP.
Variables Sociodemographic characteristics Characteristics included age, nationality (Dutch/nonDutch), educational level (no college degree/at least college degree), and net monthly income level (low: 1700 Euro/medium: 1701–2950 Euro/high: 2951 Euro). Sexual behavior Men were categorized into HIV-risk infection group based on three risk factors for HIV seroconversion identified in previous research within the ACS [3]: having receptive condomless anal sex (CAS) with casual partners; having more than five casual partners in the preceding 6 months; diagnosed gonorrhea (urethral or rectal) at ACS visit. Men reporting at least one of these factors were defined as high-risk (Hr-MSM). Those reporting none of these factors were defined as low-risk (Lr-MSM).
CAS was defined as not or not always using a condom during anal sex; condom use was measured on a fivepoint scale ranging from ‘always’ to ‘never’. Two questions concerning steady partners were combined and categorized into having no steady partner, an HIVnegative steady partner, and a steady partner with positive or unknown HIV status.
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Preexposure prophylaxis in the Netherlands Bil et al. Awareness of and beliefs about preexposure prophylaxis We asked participants if they had ever heard of PrEP. Those aware of PrEP were asked about their chief source of knowledge (multiple-choice question). All participants (aware or unaware of PrEP) were asked about their beliefs about PrEP; efficacy (measured on a 4-point scale ranging from ‘PrEP can reduce the risk of HIV by 100%’ to ‘PrEP does not reduce the risk of HIV’); efficacy in combination with always, sometimes, or never using condoms (measured in three questions, all on a 7-point scale ranging from ‘no protection’ to ‘100% protection’); and side-effects (’rare’, ‘sometimes reported’, ‘appear frequently’, ‘knowledge is still scarce’). Intention to use preexposure prophylaxis The intention to use PrEP was assessed in all MSM (aware or unaware of PrEP) by two questions: ‘How likely are you to use PrEP if it becomes available in the Netherlands?’ and ‘Are you planning on using PrEP if it becomes available in the Netherlands?’ (both measured on a 7-point scale from ‘very unlikely’ to ‘very likely’). Given their acceptable correlation (Spearman’s rho 0.7; P < 0.001), the mean score of these items was used to represent the ‘intention to use PrEP’. Intention to use PrEP was categorized based on tertiles, into low (score < 2), medium (score 2–4), and high intention (score >4). Psychosocial determinants concerning preexposure prophylaxis The questionnaire included 13 items measuring psychosocial determinants concerning PrEP. For analyses, items were combined if they measured the same psychosocial determinant and had acceptable reliability (>3 items: Cronbach’s a 0.6). This resulted in eight determinants. Three concerned perceived self-efficacy: to use PrEP, to use PrEP every day on time, and to pay for PrEP (four items: s50, s100, s500, or s1000 per month, Cronbach’s a 0.9). The other five concerned perceived emotional impact of PrEP: whether men would feel worried about PrEP side-effects, worried about PrEP efficacy, less worried about getting HIV-infected when using PrEP, ashamed about using PrEP, and relieved when using PrEP (three items: feeling liberated, relieved, and hopeful, Cronbach’s a 0.9). All items were measured on a seven-point scale (ranging from ‘very difficult’ to ‘very easy’ or ‘totally disagree’ to ‘totally agree’).
As determinants were not normally distributed and a linear association was absent, they were dichotomized at the logical mid-point of a seven-point scale, with scores 4 or less representing low perceptions and scores more than 4 representing higher perceptions. Anticipated condom use Anticipated condom use was measured by the item: ‘I would be less likely to use condoms when using PrEP’
(7-point scale ranging from ‘totally disagree’ to ‘totally agree’). As earlier, responses were dichotomized into ‘no anticipated decrease in condom use while using PrEP’ (score 4) or ‘anticipated decrease in condom use while using PrEP’ (score >4). Perceived self-efficacy to use condoms while using PrEP was measured with one item: ‘How easy would it be to continue using condoms while using PrEP?’ (7-point scale ranging from ‘very easy’ to ‘very difficult’), which was dichotomized into ‘high perceived self-efficacy’ (score 4) and ‘low perceived self-efficacy’ (score >4). Influence of preexposure prophylaxis characteristics among MSM with high intention to use preexposure prophylaxis We assessed willingness to use PrEP at various levels of monthly cost (s50, s100, s500, s1000), for different duration of usage (3, 6 months, 1, 5, and 10 years), and when less than 100% efficacy (two combined items because they had acceptable correlation: Spearman rho 0.6; P < 0.001). Willingness was analyzed for participants with a high intention to use PrEP only. Items were measured on a seven-point scale ranging from ‘definitely not willing’ to ‘very willing’. Responses were dichotomized at mid-point into ‘unwilling’ (score 4) and ‘willing’ (score >4).
Statistical analyses First, we described sociodemographic characteristics, sexual (risk) behavior, and PrEP awareness. We compared distributions of characteristics and potential determinants between Hr-MSM and Lr-MSM, using chi-square tests for categorical variables and Mann–Whitney U tests for all, not normally distributed, continuous variables. Second, we performed multinomial logistic regression analyses to explore whether sociodemographic characteristics, sexual (risk) behavior, and psychosocial determinants were associated with a medium or high intention (reference is low intention) to use PrEP. Due to the many variables, the multivariate model was built in three steps: sociodemographic characteristics and sexual (risk) behavior associated with a higher intention (overall P < 0.10) in univariate analysis were included in a multivariate model; psychosocial determinants associated with a higher intention (overall P < 0.10) in univariate analyses were included in a separate multivariate model; variables associated with a higher intention to use PrEP (overall P < 0.10) in one of the two multivariate models were included in a final multivariate model, and considered statistically significant if the overall P value was less than 0.05. In sensitivity analyses, the three HIV risk factors defining Hr-MSM (number of casual partners, receptive CAS with casual partners, gonorrhea diagnosis) were included separately in the final model. Third, we described anticipated condom use when using PrEP and employed chi-square tests to evaluate whether
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results differed among subgroups (MSM currently vs. not currently engaging in CAS and MSM with a low vs. medium vs. high intention to use PrEP). Fourth, we described the influence of PrEP characteristics on the willingness to use PrEP among MSM with initially high intention to use PrEP. Analyses were performed using STATA Intercooled 13.1 (STATA Corporation, College Station, Texas, USA).
Results Participant characteristics From June 2012 to January 2013, 466 HIV-negative MSM had a 6 monthly ACS visit, of whom 448 (96%) completed PrEP questions and were included in this study. Their median age was 40 years [interquartile range (IQR) 35–45] (Table 1), most were Dutch (92%; 404/ 440), college graduates (90%; 404/447), and had a medium income (41%; 163/397). In the preceding 6 months, men reported a median of 4 (IQR 0–11) casual partners and 64% (276/433) had a steady partner. Over half of participants (59%; 261/444) reported CAS in the preceding 6 months and 3% (11/434) were diagnosed with gonorrhea at their ACS visit. Overall, 47% (202/ 430) were defined as Hr-MSM, of whom 89% (179/201) had more than five casual partners; 30% (61/202) had receptive CAS with casual partners, and 6% (11/198) were diagnosed with gonorrhea. Hr-MSM were significantly older [median age 41 (IQR 36–45) vs. 39 years (IQR 34–43)] and less likely to have a steady partner (51 vs. 24%) than Lr-MSM. Awareness of and beliefs about preexposure prophylaxis Of the 448 participants, 54% (n ¼ 242) were aware of PrEP (Table 1). Hr-MSM were more likely to be aware of PrEP than Lr-MSM (60 vs. 50%, respectively; P ¼ 0.031). Almost half of MSM aware of PrEP (42%; 102/241) reported the ACS as their chief source of knowledge followed by the internet and a professional healthcare provider (both 10%). About one-third believed PrEP could significantly reduce the risk of HIV (38%; 168/448) and a comparable proportion was unaware of PrEP efficacy (38%; 169/ 448). A majority was unaware of PrEP side-effects (66%; 294/448), but of 154 men that were aware, 58% believed that side-effects appeared frequently. Beliefs about sideeffects did not differ between Hr-MSM and Lr-MSM. MSM believed that PrEP had a high protective effect if always combined with condoms [mean 5.5 (standard deviation [SD] 1.7)], but only medium effective if sometimes [mean 3.8 (SD 1.4)] or never [mean 3.2 (1.5)] combined with condoms. For the last two items,
Hr-MSM perceived PrEP to more effective than LrMSM (P 0.001).
Determinants of intention to use preexposure prophylaxis Of all participants, 27% (n ¼ 120) had a low intention, 60% (n ¼ 270) a medium intention, and 13% (n ¼ 58) a high intention to use PrEP. Multivariate multinomial regression analyses including sociodemographics and sexual (risk) behavior variables with a univariate P value less than 0.10 (Table 2) showed that Hr-MSM and MSM with no steady partner or with a steady partner with a positive or unknown HIV status were more likely to have higher intentions to use PrEP. Educational level became nonsignificant. In multivariate analyses including psychosocial determinants with a univariate P value less than 0.10 (Table 3), all perceptions, except those concerning worries about PrEP efficacy and about getting HIV-infected when using PrEP, were associated with higher intentions to use PrEP. In the final combined multivariate model (Table 4), including all variables with a P value less than 0.10 from tables 2 and 3, Hr-MSM were more likely to have a medium [adjusted odds ratio (aOR) 1.78 (95% confidence interval [CI] 1.07–2.97)] or high intention to use PrEP [aOR 3.92 (95% CI 1.68–9.15)] than Lr-MSM. Sensitivity analyses found that all three separate HIV risk factors defining Hr-MSM (number of casual partners, receptive CAS with casual partners, gonorrhea diagnosis) were associated with higher intentions to use PrEP, but only the number of casual partners was statistically significant (P ¼ 0.020, data not shown). The effect of steady partner decreased and became statistically nonsignificant. MSM that were aware of PrEP were also more likely to have a high intention to use PrEP [aOR 2.41 (95% CI 1.07–5.45)] than those unaware, but the overall effect on intention was not statistically significant (P ¼ 0.105). MSM with high perceived self-efficacy to use PrEP were more likely to have a high intention to use PrEP [aOR 6.15 (95% CI 2.50–15.09)] than MSM with low perceived self-efficacy (overall P < 0.001). Furthermore, having higher perceptions of relief when using PrEP was associated with a medium [aOR 2.67 (95% CI 1.32–5.40)] and high intention to use PrEP [aOR 14.87 (95% CI 5.98–37.01)]. Feelings of shame about using PrEP decreased the intention to use PrEP [aOR 0.35 (95% CI 0.19–0.62) for medium and aOR 0.22 (95% CI 0.07–0.71) for high intention], as did worries about sideeffects of PrEP [aOR 0.29 (95% CI 0.12–0.72) and aOR 0.18 (95% CI 0.06–0.54), respectively].
Anticipated condom use About one-third of participants (39%; 174/447) anticipated a decrease in their condom use during anal sex while using PrEP (Table 5). In addition, about one-quarter (26%; 115/446) had low perceived self-efficacy to use condoms
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Preexposure prophylaxis in the Netherlands Bil et al. Table 1. Characteristics, preexposure prophylaxis awareness and beliefs about preexposure prophylaxis according to sexual risk behavior among 448 HIV-negative MSM participating in the Amsterdam Cohort Studies from June 2012 through January 2013, Amsterdam, the Netherlands. Risk of HIV infectiona Total (N ¼ 448) n
Lr-MSM (n ¼ 228)
%
Age (years) (Median [IQR]) 40 [34–35] Nationality Non-Dutch 36 8.2 Dutch 404 91.8 Educational level No college degree 43 9.6 At least college degree 404 90.4 Monthly income level Low (2950 Euro) 120 30.2 Steady partner None 157 36.3 HIV-negative 214 49.4 Positive or unknown HIV status 62 14.3 Number of casual sexual partners in the preceding 6 months (Median [IQR]) 4 [0–11] CAS in the preceding 6 months (insertive and/or receptive) Currently not engaging in CAS 183 41.2 CAS with steady partner 151 34.0 CAS with casual partner 82 18.5 CAS with steady and casual partner 28 6.3 Gonorrhea at ACS visit No 423 97.5 Yes 11 2.5 Awareness of PrEP Never heard of PrEP 206 46.0 Ever heard of PrEP 242 54.0 e Chief source of knowledge about PrEP Internet 23 9.5 HIV-patient organization 8 3.3 Professional healthcare provider 23 9.5 ACS 102 42.3 Newspaper/TV 17 7.1 Friends/family 21 8.7 Other 16 6.6 Unknown 31 12.9 Beliefs about efficacy of PrEP PrEP can reduce the risk of HIV by 100% 1 0.2 PrEP can significantly reduce the risk of HIV 168 37.5 PrEP could slightly reduce the risk of HIV 103 22.9 PrEP does not reduce the risk of HIV 7 1.6 I do not know 169 37.7 Beliefs about side-effects of PrEP Side-effects are rare 2 0.5 Side-effects are sometimes reported 46 10.3 Side-effects appear frequently 70 15.6 Knowledge about side-effects is still scarce 36 8.0 I do not know 294 65.6 Beliefs about efficacy of PrEP (mean [SD]) (1. no protection - 7. 100% protection for HIV) Efficacy when you always use condoms during anal sex 5.5 [1.7] Efficacy when you sometimes use condoms during anal sex 3.8 [1.4] Efficacy when you never use condoms during anal sex 3.2 [1.5]
Hr-MSM (n ¼ 202)
n
%
n
%
P value
39
[34–43]
41
[36–45]
0.006b
21 204
9.3 90.7
15 183
7.6 92.4
0.518c
23 205
10.1 89.9
18 184
8.9 91.1
0.678c
53 90 61
26.0 44.1 29.9
57 65 55
32.2 36.7 31.1
0.274c
53 132 32
24.4 60.8 14.7
101 72 25
51.0 36.4 12.6
2950 Euro)
27 44 34
Steady partner None HIV-negative Positive or unknown HIV status HIV-risk behavior group Lr-MSM Hr-MSM
High intention to use PrEP (n ¼ 58) aOR (95% CI)
OR (95% CI)
aOR (95% CI)
Overall P valuea
1b 0.35 (0.12–1.00)
0.100
n
%
1 0.98 (0.58–1.67) 0.96 (0.57–1.62)
15 22 21
10.0 14.8 14.1
1 1.54 (0.70–3.40) 1.44 (0.65–3.17)
52.8 61.4
1 1.09 (0.48–2.48)
8 48
22.2 11.9
1 0.50 (0.18–1.38)
25 245
58.1 60.6
1 0.61 (0.26–1.46)
11 47
25.6 11.6
1b 0.27 (0.10–0.73)
23.7 27.0 28.3
65 95 78
57.0 58.3 65.0
1 0.90 (0.51–1.59) 0.95 (0.52–1.74)
22 24 8
19.3 14.7 6.7
1b 0.67 (0.32–1.42) 0.29 (0.11–0.75)
30 70 14
19.1 32.7 22.6
100 128 34
63.7 59.8 54.8
1.82 (1.10–3.01) 1b 1.33 (0.67–2.64)
1.50 (0.88–2.55) 1 1.29 (0.61–2.70)
27 16 14
17.2 7.5 22.6
3.94 (1.86–8.35) 2.22 (0.99–4.95) 1d 1b 4.38 (1.75–10.96) 3.74 (1.40–9.96)
73 40
32.3 19.6
133 129
58.8 63.2
1b 1.72 (1.09–2.71)
1b 1.63 (1.01–2.66)
20 35
8.8 17.2
1c 3.19 (1.63–6.25)
1 0.75 (0.30–1.83)
1c 2.78 (1.36–5.70)
0.044
0.016
aOR, adjusted odds ratio; CI, confidence interval; Hr-MSM, men having sex with men at high risk of HIV-infection; Lr-MSM, men having sex with men at low risk of HIV-infection; OR, odds ratio; PrEP, preexposure prophylaxis. a Overall P value of higher intention in adjusted analyses. b P < 0.05. c P < 0.01. d P < 0.001.
Influence of preexposure prophylaxis characteristics among MSM with a high intention to use preexposure prophylaxis In total, 58 men had a high intention to use PrEP, of whom a majority was willing to take PrEP daily for 3 (88%), 6 months (85%), or 1 year (74%), and about half even for 5 (59%) or 10 years (52%). There were 32 MSM (55%) who were willing to use PrEP when having to pay. Willingness to use PrEP decreased with increasing costs: 55% would take PrEP at s50 per month, but only 3% remained willing at s1000 per month. Finally, 23 MSM (40%) remained willing to take PrEP even if it were less than 100% effective.
Discussion This is the first study focusing on awareness of PrEP and intention to use PrEP among Dutch MSM. About half of the MSM in the ACS were aware of PrEP; most MSM were unaware of PrEP side-effects, and only 13% had a high intention to use PrEP. High-risk sexual behavior was
independently associated with a higher intention, as were psychosocial determinants such as high perceived selfefficacy and high perceptions of relief when using PrEP. Feelings of shame about using PrEP, worries about sideeffects, and PrEP characteristics, such as increasing costs and perceived insufficient efficacy were found to decrease the intention to use PrEP. Compared with other studies from high-income countries, where proportions of a high intention to use PrEP ranged between 28 and 74% [10–18], our proportion of 13% was relatively low. These differences are unlikely to be explained by differences in behavioral characteristics as study populations seem similar. This finding suggests that acceptability of PrEP might currently be lower in the Netherlands than elsewhere, possibly explained by differences in PrEP knowledge. Previous cost-effectiveness studies show that PrEP is most likely to be beneficial when targeting Hr-MSM, but the effect depends highly on uptake, adherence, frequency of monitoring, and duration of PrEP use [19–23]. We found
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Preexposure prophylaxis in the Netherlands Bil et al. Table 3. Multinomial logistic regression analysis of psychosocial determinants associated with the intention to use preexposure prophylaxis among 448 HIV-negative MSM participating in the Amsterdam Cohort Studies from June 2012 through January 2013, Amsterdam, The Netherlands. Low intention to use PrEP (Ref.) n ¼ 120
n
%
PrEP awareness (aware vs. unaware) Aware of PrEP 55 22.7 Perceived self-efficacy (high vs. low) High perceived self-efficacy to 17 18.7 use PrEP High perceived self-efficacy to 34 23.9a use PrEP every day on time High perceived self-efficacy to pay 18 24.0a for PrEP (50–1000 Euro/month) Perceived emotional impact of PrEP (high vs. low) High perception of worry about 112 30.3a PrEP side-effects High perception of worry about 107 30.0a PrEP efficacy High perception of decreased 46 25.0a worry about getting HIV-infected when using PrEP High perception of shame about 35 44.3a using PrEP High perception of relief when using PrEP 15 13.3a
Medium intention to use PrEP n ¼ 270
n
%
147 60.7 b
46
50.5
87 47
High intention to use PrEP n ¼ 58
OR (95% CI)
aOR (95% CI)
1.41 (0.92–2.17)
1.39 (0.88–2.18)
1.27 (0.69–2.32)
n
1.06 (0.57–1.99)
%
40 16.5
OR (95% CI)
aOR (95% CI)
2.63 (1.36–5.09)e
2.71 (1.27–5.77)d
0.035
e
