Epidemiology and Public Health Oral Abstract Session #4
Tracks
*
Sunday, May 4, 2025 |
8:30 - 10:00 |
Room 501 & 502 |
Overview
Épidémiologie et santé publique séances de présentation orale d’abrégés #4
Details
Prevention // Prévention
Speaker
Stanley Onyegbule
St. Michael's Hospital
Developing an Educational Resource to Support Healthcare Providers Counseling Gay, Bisexual, Men Who Have Sex With Men, and Transgender and Non-binary Individuals (GBMTNB) about HIV Pre-exposure Prophylaxis (PrEP) in Ontario
Abstract
Background: Findings from a study looking at PrEP uptake and its determinants (PRIMP) were discussed among stakeholders. Better counseling was identified as a potential strategy to improve access to PrEP.
Our aim was to create a resource to assist healthcare providers in providing culturally informed HIV prevention care with a focus on HIV PrEP for GBMTNB.
Methods: We drew from relevant theories to design a framework to guide the creation of an educational resource for providers. This resource was further developed using findings from PRIMP and based on the team’s professional experience. Several iterations of this document were reviewed.
A panel of 12 experts reviewed the document and independently rated its sections using 5-point Likert scales in terms of complexity, relative advantage, appropriateness, and trialability. The material was discussed in three separate subgroups, each with at least one physician, one nurse, and one community-based organization representative.
A convenience sample of 15 providers potentially interested in such a resource (12 physicians, 2 NPs, and one public health practitioner) were asked about their preferred modality of learning.
Results: The developed framework consists of four core elements that serve as a guide/approach to discussions about HIV prevention with a focus on PrEP: exploring values, confirming the need for prep, eliciting the intention to use PrEP, and preparing to start PrEP.
The panel of experts rated the material highly: 4.5/5 for complexity and appropriateness, 4.2 for relative advantage, and 4.1/5 for trialability.
Eight of the fifteen potentially interested providers indicated they would prefer an online self-paced training modality. We created a series of online eLearning modules including case vignettes, requiring approximately 75 minutes to complete.
Discussion and Conclusion:
Iterative discussions engaging various types of providers result in culturally competent, highly rated content that has the potential to improve HIV prevention care delivery.
Our aim was to create a resource to assist healthcare providers in providing culturally informed HIV prevention care with a focus on HIV PrEP for GBMTNB.
Methods: We drew from relevant theories to design a framework to guide the creation of an educational resource for providers. This resource was further developed using findings from PRIMP and based on the team’s professional experience. Several iterations of this document were reviewed.
A panel of 12 experts reviewed the document and independently rated its sections using 5-point Likert scales in terms of complexity, relative advantage, appropriateness, and trialability. The material was discussed in three separate subgroups, each with at least one physician, one nurse, and one community-based organization representative.
A convenience sample of 15 providers potentially interested in such a resource (12 physicians, 2 NPs, and one public health practitioner) were asked about their preferred modality of learning.
Results: The developed framework consists of four core elements that serve as a guide/approach to discussions about HIV prevention with a focus on PrEP: exploring values, confirming the need for prep, eliciting the intention to use PrEP, and preparing to start PrEP.
The panel of experts rated the material highly: 4.5/5 for complexity and appropriateness, 4.2 for relative advantage, and 4.1/5 for trialability.
Eight of the fifteen potentially interested providers indicated they would prefer an online self-paced training modality. We created a series of online eLearning modules including case vignettes, requiring approximately 75 minutes to complete.
Discussion and Conclusion:
Iterative discussions engaging various types of providers result in culturally competent, highly rated content that has the potential to improve HIV prevention care delivery.
Maria Victoria Dreher Wentz
Epidemiologist
Ontario HIV Treatment Network
Understanding Physicians Pre-exposure Prophylaxis (PrEP) and Antiretroviral Therapy (ART) Prescription Patterns Across Ontario, 2023
Abstract
Pre-exposure prophylaxis is an effective tool for HIV prevention, while Antiretroviral Therapy has transformed care for people living with HIV. Understanding physicians’ prescribing patterns of PrEP and ART, in Ontario can show the availability of care across the province and can lead to targeted education efforts.
Data were obtained from IQVIA, a private company whose drugs dispensation database reflects more than 70% of the retail pharmacies in Ontario. IQVIA’s algorithms classified prescriptions for TDF/FTC and TAF/FTC as being for PrEP, hepatitis B therapy, post-exposure prophylaxis, or ART. Prescribing physicians were pre-classified in a prescription ranking from Q1 (PrEP: 1016-7012 Rx; ART: 2743-6705 Rx) to Q5 (PrEP: 1-73 Rx; ART:1-540 Rx). Data are broken down by PrEP or ART, by number of physicians, and specialties.
Among 1286 PrEP prescribing physicians, the majority were in family medicine (1033,80.3%), general practice (124, 9.6%), infectious diseases (62, 4.8%), or residents (30, 2.3%). Most PrEP prescribers were in Toronto (592), Ottawa (147), Hamilton (59) and York (55). Only 10 physicians were ranked Q1 (located in Halton, Hamilton, Peel, Ottawa and Toronto) with 91.1% (1276) of the physicians ranked Q5.
Among 843 ART prescribers, family medicine (480, 56.9%) and infectious diseases (104, 12.3%) were the leading specialties, followed by residents (49, 5.8%) and internal medicine (30, 3.5%). Prescribers ranked Q1 were located in the GTA (6), Ottawa (1), Windsor (2) Thunder Bay (1) and Sudbury (1). 91.2% of the prescribers ranked as Q5. Toronto (320), Ottawa (98), Hamilton (56), Middlesex-London (44) and Peel (42) had the highest ART prescribers counts.
Based on drug dispensing in Ontario, the majority of PrEP and ART prescriptions were driven by a small proportion of physicians (Q1s). These findings highlight gaps in prescribing patterns, providing an opportunity for targeted programs aiming to strengthen physicians’ capacity in prescribing PrEP and ART.
Data were obtained from IQVIA, a private company whose drugs dispensation database reflects more than 70% of the retail pharmacies in Ontario. IQVIA’s algorithms classified prescriptions for TDF/FTC and TAF/FTC as being for PrEP, hepatitis B therapy, post-exposure prophylaxis, or ART. Prescribing physicians were pre-classified in a prescription ranking from Q1 (PrEP: 1016-7012 Rx; ART: 2743-6705 Rx) to Q5 (PrEP: 1-73 Rx; ART:1-540 Rx). Data are broken down by PrEP or ART, by number of physicians, and specialties.
Among 1286 PrEP prescribing physicians, the majority were in family medicine (1033,80.3%), general practice (124, 9.6%), infectious diseases (62, 4.8%), or residents (30, 2.3%). Most PrEP prescribers were in Toronto (592), Ottawa (147), Hamilton (59) and York (55). Only 10 physicians were ranked Q1 (located in Halton, Hamilton, Peel, Ottawa and Toronto) with 91.1% (1276) of the physicians ranked Q5.
Among 843 ART prescribers, family medicine (480, 56.9%) and infectious diseases (104, 12.3%) were the leading specialties, followed by residents (49, 5.8%) and internal medicine (30, 3.5%). Prescribers ranked Q1 were located in the GTA (6), Ottawa (1), Windsor (2) Thunder Bay (1) and Sudbury (1). 91.2% of the prescribers ranked as Q5. Toronto (320), Ottawa (98), Hamilton (56), Middlesex-London (44) and Peel (42) had the highest ART prescribers counts.
Based on drug dispensing in Ontario, the majority of PrEP and ART prescriptions were driven by a small proportion of physicians (Q1s). These findings highlight gaps in prescribing patterns, providing an opportunity for targeted programs aiming to strengthen physicians’ capacity in prescribing PrEP and ART.
Roseline Dzekem Dine
Student
McMaster University
Sexually Transmitted Infections Risk Compensation in the Context of Dapivirine Vaginal Ring Use for HIV Prevention among Women in Africa: A Scoping Review
Abstract
Background
Sexually transmitted infections (STIs) remain a critical public health challenge globally, with Africa facing the highest incidence and mortality rates. The Dapivirine Vaginal Ring (DPV-VR) is a discreet HIV prevention tool for women but does not protect against other non-HIV STIs. Its use may inadvertently lead to complacency around other STI transmissions, contributing to their spread. This scoping review aimed to assess the prevalence of STI acquisition and the sociocultural, economic, and demographic factors influencing STI risk among African women using DPV-VR. The review also examines proposed policies and interventions to reduce STI risk for these women.
Method
We searched electronic databases such as Ovid platform, MEDLINE, Embase, Global Health, CINAHL, Web of Science, Cochrane Library databases, Social Sciences Citation index, and Gray literature from January 2014 to July 2024. The Rayyan tool was used to screen the title and abstract, whereas DistillerSR Version 2 was used for the full text screening. The qualitative data was analyzed for themes using QDA Miner Lite, while the numeric data was analyzed using Microsoft Excel Package. This scoping review followed the PRISMA-ScR guidelines.
Result
Out of 1,247 papers, 11 were selected. The overall prevalence of any STI was 42.4%, with specific rates for chlamydia (17%), Neisseria gonorrhoeae (9.2%), Trichomonas vaginalis (16.7%), and syphilis (0.9%). Sociocultural, economic, and demographic factors, including poverty, patriarchy, location, knowledge, and age, were found to influence STI risk among women using DPV-VR. Suggested policies include routine STI screening, education, targeted interventions, and partner treatment frameworks to effectively control STIs.
Conclusion
Holistic sexual health services are needed to support the use of DPV-VR and prevent other STIs. Further research on biomedical tools that prevent both HIV and other STIs is crucial to address this gap.
Keywords: Dapivirine Vaginal Ring, Sexually transmitted infections, Women, Africa
Sexually transmitted infections (STIs) remain a critical public health challenge globally, with Africa facing the highest incidence and mortality rates. The Dapivirine Vaginal Ring (DPV-VR) is a discreet HIV prevention tool for women but does not protect against other non-HIV STIs. Its use may inadvertently lead to complacency around other STI transmissions, contributing to their spread. This scoping review aimed to assess the prevalence of STI acquisition and the sociocultural, economic, and demographic factors influencing STI risk among African women using DPV-VR. The review also examines proposed policies and interventions to reduce STI risk for these women.
Method
We searched electronic databases such as Ovid platform, MEDLINE, Embase, Global Health, CINAHL, Web of Science, Cochrane Library databases, Social Sciences Citation index, and Gray literature from January 2014 to July 2024. The Rayyan tool was used to screen the title and abstract, whereas DistillerSR Version 2 was used for the full text screening. The qualitative data was analyzed for themes using QDA Miner Lite, while the numeric data was analyzed using Microsoft Excel Package. This scoping review followed the PRISMA-ScR guidelines.
Result
Out of 1,247 papers, 11 were selected. The overall prevalence of any STI was 42.4%, with specific rates for chlamydia (17%), Neisseria gonorrhoeae (9.2%), Trichomonas vaginalis (16.7%), and syphilis (0.9%). Sociocultural, economic, and demographic factors, including poverty, patriarchy, location, knowledge, and age, were found to influence STI risk among women using DPV-VR. Suggested policies include routine STI screening, education, targeted interventions, and partner treatment frameworks to effectively control STIs.
Conclusion
Holistic sexual health services are needed to support the use of DPV-VR and prevent other STIs. Further research on biomedical tools that prevent both HIV and other STIs is crucial to address this gap.
Keywords: Dapivirine Vaginal Ring, Sexually transmitted infections, Women, Africa
Carmen Logie
Professor
University Of Toronto
Utilizing an Ecosocial Approach to Examine Associations Between Wildfire Exposure and other Hazardous Socio-Environmental Factors with HIV Prevention Outcomes among Northern and Indigenous Adolescents in the Northwest Territories, Canada
Abstract
Background: Condom use self-efficacy (CUSE), encompassing knowledge, relational dynamics, and sexual agency, facilitates youth HIV prevention engagement. We applied an ecosocial lens to consider how hazardous environments, such as those wrought by climate change and extreme weather events (EWE), social marginalization, and socio-economic inequities, affect HIV prevention outcomes such as CUSE. We examined associations between ecosocial factors, including EWE exposure to the 2023 wildfires, and CUSE among Northern and Indigenous adolescents in the Northwest Territories (NWT), Canada.
Methods: This community-based study collected cross-sectional survey data (2023-2024) with a purposive sample of adolescent secondary-school students aged 13-18 in 17 NWT communities. We conducted structural equation modeling (SEM) using maximum likelihood estimation to examine pathways from a latent construct of ecosocial factors (gender [cisgender girls]), sexually diverse identity, Indigenous identity, rurality, food insecurity, 2023 NWT wildfire exposure [Traumatic Exposure Severity Scale]) to CUSE. Self-esteem was tested as a mediator in this relationship.
Results: The sample comprised n=290 participants (mean age: 13.68 years, standard deviation: 1.69; cisgender girls: 57%, n=137; cisgender boys: 50.35%, n=145; gender diverse: 2.09%, n=6; sexually diverse [gay, lesbian, bisexual, queer, other]: 18.37%, n=52). Most identified as Indigenous (68.79%, n=194) and lived in rural communities outside of Yellowknife (79.10%, n=212). Over half (54.47%; n=134) reported EWE exposure to the 2023 wildfires. The final SEM model demonstrated good fit (Chi²=26.08, p=0.128; CFI=0.971; RMSEA=0.052 [90% CI = 0.001–0.681]; SRMR=0.060). Ecosocial factors were significantly associated with lower CUSE (β= -0.149, p<0.05), with self-esteem partially mediating this effect (β= -0.117, p<0.05).
Conclusion: Ecosocial factors, including EWE exposure to the 2023 NWT wildfires, socially marginalized identities (Indigeneity, sexual diversity, gender, rurality), and socio-economic disparities (food insecurity), were associated with reduced CUSE, in part via reduced self-esteem. Multi-level climate-informed strategies that centre social equity are needed to advance HIV prevention with Northern and Indigenous NWT adolescents.
Methods: This community-based study collected cross-sectional survey data (2023-2024) with a purposive sample of adolescent secondary-school students aged 13-18 in 17 NWT communities. We conducted structural equation modeling (SEM) using maximum likelihood estimation to examine pathways from a latent construct of ecosocial factors (gender [cisgender girls]), sexually diverse identity, Indigenous identity, rurality, food insecurity, 2023 NWT wildfire exposure [Traumatic Exposure Severity Scale]) to CUSE. Self-esteem was tested as a mediator in this relationship.
Results: The sample comprised n=290 participants (mean age: 13.68 years, standard deviation: 1.69; cisgender girls: 57%, n=137; cisgender boys: 50.35%, n=145; gender diverse: 2.09%, n=6; sexually diverse [gay, lesbian, bisexual, queer, other]: 18.37%, n=52). Most identified as Indigenous (68.79%, n=194) and lived in rural communities outside of Yellowknife (79.10%, n=212). Over half (54.47%; n=134) reported EWE exposure to the 2023 wildfires. The final SEM model demonstrated good fit (Chi²=26.08, p=0.128; CFI=0.971; RMSEA=0.052 [90% CI = 0.001–0.681]; SRMR=0.060). Ecosocial factors were significantly associated with lower CUSE (β= -0.149, p<0.05), with self-esteem partially mediating this effect (β= -0.117, p<0.05).
Conclusion: Ecosocial factors, including EWE exposure to the 2023 NWT wildfires, socially marginalized identities (Indigeneity, sexual diversity, gender, rurality), and socio-economic disparities (food insecurity), were associated with reduced CUSE, in part via reduced self-esteem. Multi-level climate-informed strategies that centre social equity are needed to advance HIV prevention with Northern and Indigenous NWT adolescents.
Felipe Duailibe
Epidemiologist
Bc-cfe
Changes in Sexual Behaviour Following HIV Pre-Exposure Prophylaxis Initiation Among Gay, Bisexual and Other Men Who Have Sex with Men in Canada’s Three Largest Cities
Abstract
Introduction
Gay, bisexual and other men who have sex with men (GBM) who use HIV pre-exposure prophylaxis (PrEP) reduce their likelihood of acquiring HIV, but are more likely to engage in sexual practices exposing them to other sexually transmitted infections (STIs). We examined within-person changes in sexual behaviour after PrEP initiation among GBM in Canada’s three largest cities.
Methods
Sexually active GBM, aged ≥16 years, were recruited using respondent-driven sampling in Montreal, Toronto and Vancouver (02/2017-08/2019). Participants completed a computer-assisted self-interview and tests for STIs at enrolment and every 6–12 months until 02/2020 (pre-COVID). HIV-negative participants were included in this analysis if they (1) initiated PrEP after enrolment, and (2) had at least one visit post-PrEP initiation. We analyzed changes in sexual behaviours and HIV Incidence Risk Index (HIRI)-MSM scores after PrEP initiation using McNemar’s and Wilcoxon signed-rank tests for each city.
Results
A total of 288 GBM were included (Montreal: 119, Toronto: 39, Vancouver: 130). The proportion of participants with a HIRI-MSM score ≥10 increased across the three cities from 73.8%-84.6% prior to PrEP initiation to 77.7%-87.2% after PrEP initiation. Median HIRI-MSM scores significantly increased, from 18 to 19 in Montreal (p=0.013), from 18 to 23 in Toronto (p=0.016) and from 15.5 to 18 in Vancouver (p=0.004). The median number of partners with any condomless anal sex in the past six months increased significantly from 4 to 6 in Montreal (p<0.001), but not in Toronto (5 to 6, p=0.196) or Vancouver (3 to 4, p=0.130). Engagement in chemsex or group sex did not change after PrEP initiation in any city (ps>0.05).
Conclusions
Overall, HIV PrEP programs are reaching and supporting GBM who will benefit from this prevention intervention. PrEP is associated with changes in sexual behaviour that warrant ongoing attention to sexual health promotion.
Gay, bisexual and other men who have sex with men (GBM) who use HIV pre-exposure prophylaxis (PrEP) reduce their likelihood of acquiring HIV, but are more likely to engage in sexual practices exposing them to other sexually transmitted infections (STIs). We examined within-person changes in sexual behaviour after PrEP initiation among GBM in Canada’s three largest cities.
Methods
Sexually active GBM, aged ≥16 years, were recruited using respondent-driven sampling in Montreal, Toronto and Vancouver (02/2017-08/2019). Participants completed a computer-assisted self-interview and tests for STIs at enrolment and every 6–12 months until 02/2020 (pre-COVID). HIV-negative participants were included in this analysis if they (1) initiated PrEP after enrolment, and (2) had at least one visit post-PrEP initiation. We analyzed changes in sexual behaviours and HIV Incidence Risk Index (HIRI)-MSM scores after PrEP initiation using McNemar’s and Wilcoxon signed-rank tests for each city.
Results
A total of 288 GBM were included (Montreal: 119, Toronto: 39, Vancouver: 130). The proportion of participants with a HIRI-MSM score ≥10 increased across the three cities from 73.8%-84.6% prior to PrEP initiation to 77.7%-87.2% after PrEP initiation. Median HIRI-MSM scores significantly increased, from 18 to 19 in Montreal (p=0.013), from 18 to 23 in Toronto (p=0.016) and from 15.5 to 18 in Vancouver (p=0.004). The median number of partners with any condomless anal sex in the past six months increased significantly from 4 to 6 in Montreal (p<0.001), but not in Toronto (5 to 6, p=0.196) or Vancouver (3 to 4, p=0.130). Engagement in chemsex or group sex did not change after PrEP initiation in any city (ps>0.05).
Conclusions
Overall, HIV PrEP programs are reaching and supporting GBM who will benefit from this prevention intervention. PrEP is associated with changes in sexual behaviour that warrant ongoing attention to sexual health promotion.
Ying Wang
Post-doctoral Research Fellow
University of Toronto
HIV Prevention Outcome Trends Among Northern and Indigenous Adolescents in the Northwest Territories, Canada: A Repeated Cross-sectional Study of Arts-Based Sexual Health Workshops
Abstract
Background: Arts-based approaches hold promise for improving adolescent sexual health, yet few longitudinal studies evaluated their effectiveness. This study investigated trends in HIV prevention outcomes among adolescents in the Northwest Territories (NWT), Canada, assessing outcomes before and after arts-based sexual health workshop participation.
Methods: This single-group pre- and post-test study examined sexual health workshops implemented by FOXY (Fostering Open eXpression among Youth) and SMASH (Strengths, Masculinities, and Sexual Health), a Northern and Indigenous sexual health organization, with adolescents aged 13–18 in secondary schools across 17 NWT communities between 2018-2023. Surveys measured socio-demographic characteristics, HIV knowledge, condom use self-efficacy (CUSE), and self-esteem. A repeated cross-sectional analysis using mixed-effect models across six waves assessed changes from pre- to post-workshop and explored related factors over time.
Results: Among the entire sample (N=1579; cisgender girls: n=735, 46.67%; cisgender boys: n=774, 49.14%; gender diverse: n=66, 4.19%; Two-sprite, lesbian, gay, bisexual, and queer [2SLGBQ+]: n=296, 19.33%), nearly three quarters (n=1091, 72.49%) identified as Indigenous. Most (n=1796, 73.19%) resided outside of Yellowknife in rural communities. Results suggest that attendance at the FOXY/SMASH sexual health school-based workshops was associated with increased HIV knowledge, CUSE, and self-esteem. There was a large, positive effect size association between workshop attendance and HIV knowledge (r=1.26), and small effect sizes for CUSE (r=0.11) and self-esteem (r=0.05). The difference in CUSE and self-esteem pre-post workshop remained similar over the years (Adjusted coefficient (Acoef): 0.15; 95% CI:-0.01, 0.30). The pre-post workshop changes in HIV knowledge increased over time among young women (Acoef: 0.63; 95% CI: 0.40, 0.86; p<0.001) and 2SLGBQ+ youth (Acoef: 0.35; 95% CI: 0.04, 0.66; p<0.05).
Conclusion: Arts-based HIV prevention approaches show promise in enhancing HIV knowledge, condom use self-efficacy and self-esteem among Northern and Indigenous youth in the NWT. Findings signal the continued need for such HIV prevention approaches over time.
Methods: This single-group pre- and post-test study examined sexual health workshops implemented by FOXY (Fostering Open eXpression among Youth) and SMASH (Strengths, Masculinities, and Sexual Health), a Northern and Indigenous sexual health organization, with adolescents aged 13–18 in secondary schools across 17 NWT communities between 2018-2023. Surveys measured socio-demographic characteristics, HIV knowledge, condom use self-efficacy (CUSE), and self-esteem. A repeated cross-sectional analysis using mixed-effect models across six waves assessed changes from pre- to post-workshop and explored related factors over time.
Results: Among the entire sample (N=1579; cisgender girls: n=735, 46.67%; cisgender boys: n=774, 49.14%; gender diverse: n=66, 4.19%; Two-sprite, lesbian, gay, bisexual, and queer [2SLGBQ+]: n=296, 19.33%), nearly three quarters (n=1091, 72.49%) identified as Indigenous. Most (n=1796, 73.19%) resided outside of Yellowknife in rural communities. Results suggest that attendance at the FOXY/SMASH sexual health school-based workshops was associated with increased HIV knowledge, CUSE, and self-esteem. There was a large, positive effect size association between workshop attendance and HIV knowledge (r=1.26), and small effect sizes for CUSE (r=0.11) and self-esteem (r=0.05). The difference in CUSE and self-esteem pre-post workshop remained similar over the years (Adjusted coefficient (Acoef): 0.15; 95% CI:-0.01, 0.30). The pre-post workshop changes in HIV knowledge increased over time among young women (Acoef: 0.63; 95% CI: 0.40, 0.86; p<0.001) and 2SLGBQ+ youth (Acoef: 0.35; 95% CI: 0.04, 0.66; p<0.05).
Conclusion: Arts-based HIV prevention approaches show promise in enhancing HIV knowledge, condom use self-efficacy and self-esteem among Northern and Indigenous youth in the NWT. Findings signal the continued need for such HIV prevention approaches over time.
