Mark Gilbert

Background: Sexually transmitted and blood-borne infection (STBBI) rates have risen, disproportionately affecting equity-deserving populations who face barriers to testing. BC’s digital STBBI testing service GetCheckedOnline (GCO) expands access, however, funding constraints have stalled further expansion. As a cost-saving measure, decision-makers have considered reducing potentially unnecessary testing. Currently, GCO routinely recommends chlamydia, gonorrhea, syphilis and HIV tests for all clients, warranting exploration of over-recommendation. This thesis examined GCO utilisation by demographic and behavioural characteristics and explored the extent of potential over-recommendation based on clinical guidelines.Methods: A retrospective cohort study was conducted using GCO program data of repeat testers from September 2014 to December 2024. Self-reported demographic and behavioural characteristics, aligned with the Andersen Healthcare Utilisation model, were used to explore associations with repeat testing and potential over-recommendation. Andersen-Gill survival models estimated risks of repeat testing, and negative binomial regression estimated rates of potential over-recommendation. Positivity rates were compared across recommendation categories.Results: Among 25,728 repeat clients, repeat testing was positively associated with racialised clients, reporting no condom use, multiple partners, previous STBBI diagnosis, HCV risk, and partners reporting STBBIs. Negative associations were observed for clients under 30 and those reporting symptoms, while gender identity and client-partner gender groups showed time-varying effects. Most potential over-recommendations (96%) occurred when clients tested within three months of a previous episode. Overall, 27.8% of screening episodes were classified as potential over-recommendations, with lower rates among women, those with unknown gender identity and older adults, and higher rates among racialised clients, and those reporting no condom use, multiple partners, previous STBBI diagnosis, and HCV risk. Positivity was higher among potential over-recommendations (4.1%) than non-over-recommendations (3.5%, p 0.01).Conclusions: Repeat testing and potential over-recommendations were shaped by similar demographic and behavioural characteristics. As over-recommendation mainly reflected high-frequency testing, eliminating such episodes could reduce utilisation but pose potential testing barriers and miss diagnoses. Strategies that optimise resources while maintaining autonomy and accessibility are needed.

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Background: Globally, sexually transmitted infections (STIs) have been steadily increasing and remain a concern for sexual and reproductive health. In British Columbia (BC), infectious syphilis has remained a concern among males and gay, bisexual, and men who have sex with men (gbMSM) populations over the last 10 years, but more recently there has been an increase in infectious syphilis cases among females and heterosexual populations.2 There is a lack of knowledge on the impacts and spatial location of the infectious syphilis outbreak among females and heterosexual populations in BC. Objective: This thesis aims to identify infectious syphilis cluster neighbourhoods among gbMSM and heterosexual populations in BC. Specifically, this thesis addresses knowledge gaps by identifying infectious syphilis cases and cluster patterns in BC from 2018 to 2022. Methods: In BC, the Provincial Surveillance System is a collection of all syphilis case data retained by the British Columbia Centre for Disease Control (BCCDC). Bivariate analysis was conducted on infectious syphilis case data to determine missingness of spatial data from 2018 to 2022. Choropleth maps were created for infectious syphilis rates for male, female, and heterosexual populations and syphilis cases for gbMSM populations. Additionally, infectious syphilis clusters were mapped for gbMSM and heterosexual populations. Results: Rates of infectious syphilis were highest for male and female populations in Vancouver, Sunshine Coast, and Surrey. Additional higher rate neighbourhoods for males included Richmond, North Vancouver, New Westminster, Nanaimo, and Victoria. Additional neighbourhoods for females included Richmond, Squamish, Dawson Creek, Prince George, Thornhill, Fort St. John, Williams Lake, Nanaimo. For gbMSM syphilis cases were highest in Vancouver, Richmond, Burnaby, Surrey, and Victoria. Statistically significant clusters (p0.05) were found among gbMSM populations in New Westminster, Richmond, Burnaby, and Victoria. Statistically significant clusters were found among heterosexual populations in Vancouver, Surrey, Kelowna, Kamloops, and Prince George. Conclusions: Our findings confirm there are two different infectious syphilis outbreaks occurring in BC. One is among gbMSM populations located in the Greater Vancouver Region (GVR) neighbourhoods and one among heterosexual populations located in the GVR and extending out to interior and northern parts of the province.

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Introduction: Digital interventions for sexually transmitted and blood-borne infections (STBBI) testing are one strategy to overcome barriers to accessing provider-based testing. Despite evidence of overall effectiveness, these interventions might replicate existing health inequities. Exploring awareness of services as an implementation outcome can assist in understanding differential uptake by potential users, yet few studies have assessed service awareness. GetCheckedOnline is a digital intervention for STBBI testing in British Columbia (BC), Canada. This study evaluates awareness of GetCheckedOnline in communities where it is available outside Vancouver from a health equity perspective.Methods: From July to September 2022, a survey evaluated awareness, reported use and intention to use GetCheckedOnline in Kamloops, Kimberley, Maple Ridge, Nelson and Greater Victoria, BC, using online and in-person recruitment and oversampling of populations known to face barriers to testing. The implementation outcome of awareness was analyzed through Directed-acyclic graphs (DAG) informed logistic regression modelling to examine differences according to age, gender identity, race/ethnicity, sexual identity, educational attainment, and income. Intersections between gender and race/ethnicity and sexual identity and ethnicity were also studied. Results: The final sample included 1,658 participants, of whom a large proportion comprised members of equity-owed populations. Overall awareness was 36%, with 56% of those aware having used the service (20% of the total sample). A higher likelihood of awareness was found in participants identifying outside the man/woman gender binary, transgender participants, non-heterosexual people, Indigenous individuals and People of Color. A lower likelihood of awareness was found in the lower income group and people aged outside the range of 25 to 29 years. Discussion: This health equity analysis showed that the overall proportion of 1 in 3 people surveyed being aware of the service is not equally distributed in the communities studied. The pattern of awareness distribution in the sample, in some cases, favoured equity-owed groups, while other observed differences favoured more privileged groups. These findings can provide guidance for service promotion, including the identification of populations for whom it is necessary to evaluate the appropriateness of GetCheckedOnline to ensure the service can be used to overcome barriers and meet population testing needs.

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Background and Objectives: Transgender, non-binary and gender non-conforming (herein, “TGNC”) youth (15-24 years old) face overlapping minority stressors (e.g., gender discrimination, lack of access to gender-affirming care, rejection, violence) that contribute to mental health inequities. TGNC youth also use substances at higher rates when compared to cisgender youth, including some of the highest rates of cannabis use in Canada. This thesis will discuss how cannabis use features within the gender experiences of TGNC youth. Methods: This thesis draws on a community-based participatory research approach and photovoice methodology. We conducted in-depth, semi-structured interviews with 27 TGNC youth (15-24 years old) from across British Columbia. Interviews were designed to elicit discussions about the photos youth had taken as well as various gender and mental health experiences related to their cannabis use. Analysis and identification of emergent themes was guided by social constructivist grounded theory as well as queer and trans theorizing and informed by community-based research approaches through regular meetings with our team’s Youth Advisory Committee comprised of TGNC youth who use substances. Results: Three overarching themes pertaining to cannabis use and gender experiences amongst TGNC youth were generated. First, cannabis is purposefully and strategically used by TGNC youth to enact gender expressions and forms of embodiment. Second, cannabis supports introspective thought to mobilize the identity discovery and development of TGNC youth. Finally, cannabis offers a vehicle through which TGNC youth can access moments of gender euphoria and affirmation. Together, these results illustrate that TGNC youth use cannabis based on diverse motivations often related to their shared experience navigating a cisheteropatriarchal society.Conclusions: These findings identify how TGNC youth use cannabis to purposefully and strategically facilitate their mental health, well-being, identity development and self-expression. This research reveals critically important experiential and embodied dimensions of cannabis use that have not historically been considered in cannabis-related policy and the provision of care, including mental health and substance use-related care. Ultimately, these findings underscore the importance of advancing understandings of cannabis use that transcend the confines of the gender binary.

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Background: Criminalizing any aspect of sex work undermines the occupational health and safety of sex workers and perpetuates conditions that increase their risk of experiencing workplace violence. However, there has been very limited research conducted on violence against men and non-binary sex workers (MNBSWs) and the impacts that Canada’s current end-demand sex work criminalization and other intersecting structural conditions have on MNBSWs’ experiences with workplace violence. Therefore, the objective of this thesis is to examine how end-demand legislation and intersecting structural conditions and modes of oppression, such as online regulation, punitive policing, and gender stereotypes, shape MNBSWs’ experiences with workplace violence in British Columbia. Methods: This research draws on 21 semi-structured interviews with MNBSWs in British Columbia between 2020-2021. Data were thematically analyzed using a hybrid conceptual framework that draws on a structural determinants of health framework and intersectionality. Community partners and people with sex work experience were involved at every stage of the research, from study design to data interpretation. Findings: While the majority of participants felt that sex work is not inherently dangerous, findings showed how MNBSWs’ experiences with violence are shaped by end-demand criminalization and other intersecting structural conditions. For online-based MNBSWs, findings showed that end-demand criminalization, online regulations, and sex work stigma created barriers to accessing online platforms and limited their ability to enact safety strategies online, such as screening clients and negotiating services prior to meeting clients in-person. Concurrently, findings demonstrated that MNBSWs’ ability to report violence to the police is compromised due to intersecting sex work and substance use criminalization and stigmatization, anti-Indigenous racism, anti-poverty stigma, homophobia, transphobia, and gender stereotypes. Conclusions: These findings are some of the first empirical evidence to show how MNBSWs’ experiences with violence are shaped by Canada’s end-demand sex work criminalization and other intersecting and mutually constitutive structural conditions. In addition to decriminalizing sex work, these findings demonstrate the need to center MNBSWs’ experiences in policy and program development that target workplace violence against sex workers, including developing strategies to destigmatize sex work, creating community-based systems for reporting violence, and implementing progressive online policies that prioritize sex worker safety.

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