Diagnostic yield as an important metric for the evaluation of novel tuberculosis tests: rationale and guidance for future research.

Better access to tuberculosis testing is a key priority for fighting tuberculosis, the leading cause of infectious disease deaths in people. Despite the roll-out of molecular WHO-recommended rapid diagnostics to replace sputum smear microscopy over the past decade, a large diagnostic gap remains. Of the estimated 10·6 million people who developed tuberculosis globally in 2022, more than 3·1 million were not diagnosed. An exclusive focus on improving tuberculosis test accuracy alone will not be sufficient to close the diagnostic gap for tuberculosis. Diagnostic yield, which we define as the proportion of people in whom a diagnostic test identifies tuberculosis among all people we attempt to test for tuberculosis, is an important metric not adequately explored. Diagnostic yield is particularly relevant for subpopulations unable to produce sputum such as young children, people living with HIV, and people with subclinical tuberculosis. As more accessible non-sputum specimens (eg, urine, oral swabs, saliva, capillary blood, and breath) are being explored for point-of-care tuberculosis testing, the concept of yield will be of growing importance. Using the example of urine lipoarabinomannan testing, we illustrate how even tests with limited sensitivity can diagnose more people with tuberculosis if they enable increased diagnostic yield. Using tongue swab-based molecular tuberculosis testing as another example, we provide definitions and guidance for the design and conduct of pragmatic studies that assess diagnostic yield. Lastly, we show how diagnostic yield and other important test characteristics, such as cost and implementation feasibility, are essential for increased effective population coverage, which is required for optimal clinical care and transmission impact. We are calling for diagnostic yield to be incorporated into tuberculosis test evaluation processes, including the WHO Grading of Recommendations, Assessment, Development, and Evaluations process, providing a crucial real-life implementation metric that complements traditional accuracy measures.

Self-tests for COVID-19: What is the evidence? A living systematic review and meta-analysis (2020-2023).

COVID-19 self-testing strategy (COVIDST) can rapidly identify symptomatic and asymptomatic SARS-CoV-2-infected individuals and their contacts, potentially reducing transmission. In this living systematic review, we evaluated the evidence for real-world COVIDST performance. Two independent reviewers searched six databases (PubMed, Embase, Web of Science, World Health Organization database, Cochrane COVID-19 registry, Europe PMC) for the period April 1st, 2020, to January 18th, 2023. Data on studies evaluating COVIDST against laboratory-based conventional testing and reported on diagnostic accuracy, feasibility, acceptability, impact, and qualitative outcomes were abstracted. Bivariate random effects meta-analyses of COVIDST accuracy were performed (n = 14). Subgroup analyses (by sampling site, symptomatic/asymptomatic infection, supervised/unsupervised strategy, with/without digital supports) were conducted. Data from 70 included studies, conducted across 25 countries with a median sample size of 817 (range: 28-784,707) were pooled. Specificity and DOR was high overall, irrespective of subgroups (98.37-99.71%). Highest sensitivities were reported for: a) symptomatic individuals (73.91%, 95%CI: 68.41-78.75%; n = 9), b) mid-turbinate nasal samples (77.79%, 95%CI: 56.03-90.59%; n = 14), c) supervised strategy (86.67%, 95%CI: 59.64-96.62%; n = 13), and d) use of digital interventions (70.15%, 95%CI: 50.18-84.63%; n = 14). Lower sensitivity was attributed to absence of symptoms, errors in test conduct and absence of supervision or a digital support. We found no difference in COVIDST sensitivity between delta and omicron pre-dominant period. Digital supports increased confidence in COVIDST reporting and interpretation (n = 16). Overall acceptability was 91.0-98.7% (n = 2) with lower acceptability reported for daily self-testing (39.5-51.1%). Overall feasibility was 69.0-100.0% (n = 5) with lower feasibility (35.9-64.6%) for serial self-testing. COVIDST decreased closures in school, workplace, and social events (n = 4). COVIDST is an effective rapid screening strategy for home-, workplace- or school-based screening, for symptomatic persons, and for preventing transmission during outbreaks. These data will guide COVIDST policy. Our review demonstrates that COVIDST has paved the way for self-testing in pandemics worldwide.

Real world outcomes of distributing Lucira Check-It® COVID self-tests in Ontario, Canada: the GetaKit COVID study.

BACKGROUND: In Ontario, Canada we developed and implemented an online screening algorithm for the distribution of HIV self-tests, known as GetaKit. During the COVID pandemic, we adapted the GetaKit algorithm to screen for COVID based on population and infection data and distributed COVID rt-LAMP self-tests (using the Lucira Check-It®) to eligible participants. METHODS: GetaKit/COVID was a prospective observational study that occurred over a 7-month period from September 2021 to April 2022. All potential participants completed an online registration and risk assessment, including demographic information, COVID symptoms and risk factors, and vaccination status. Bivariate comparisons were performed for three outcomes: results reporting status, vaccination status, and COVID diagnosis status. Data were analysed using Chi-Square for categorial covariates and Independent Samples T-Test and Mann-Whitney U test for continuous covariates. Bivariate logistic regression models were applied to examine associations between the covariates and outcomes. RESULTS: During the study period, we distributed 6469 COVID self-tests to 4160 eligible participants; 46% identified as Black, Indigenous or a Person of Colour (BIPOC). Nearly 70% of participants reported their COVID self-test results; 304 of which were positive. Overall, 91% also reported being vaccinated against COVID. Statistical analysis found living with five or fewer people, having tested for COVID previously, and being fully vaccinated were positive factors in results reporting. For COVID vaccination, people from large urban centers, who identified their ethnicity as white, and who reported previous COVID testing were more likely to be fully vaccinated. Finally, being identified as a contact of someone who had tested positive for COVID and the presence of COVID-related symptoms were found to be positive factors in diagnosis. CONCLUSIONS: While most participants who accessed this service were vaccinated against COVID and the majority of diagnoses were identified in participants who had symptoms of, or an exposure to, COVID, our program was able to appropriately link participants to recommended follow-up based on reported risks and results. These findings highlight the utility of online screening algorithms to provide health services, particularly for persons with historical barriers to healthcare access, such as BIPOC or lower-income groups.

How much does HIV self-testing cost in low and middle income countries? A systematic review of evidence from economic studies.

Objectives: HIV self-testing (HIVST) has been proposed as an innovative strategy to diagnose human immunodeficiency virus (HIV). While HIVST offers the potential to broaden accessibility of early HIV diagnosis and treatment initiation, this testing strategy incurs additional cost and requires confirmatory testing and treatment. We have conducted the first systematic review to summarize the current economic literature for HIVST in low- and middle-income countries (LMICs). Design: A search strategy was developed including key terms for HIV, self-testing and cost-effectiveness and was conducted in Medline and Embase databases. Studies were included that reported costs per outcome and included both cost-effectiveness and cost-utility outcome measures. The search strategy identified publications up until August 15, 2023 were included. Abstract and full text screening was conducted and a standardized data abstraction form was used for included studies. Costs are reported in USD, 2020. Results: Our search strategy identified 536 total titles from the search strategy, which were screened down to 25 relevant studies that provided both cost and outcome data on HIVST. There was significant heterogeneity in the HIVST intervention, study population, costs and outcomes reported among included studies. Cost per person tested ranged from $1.09-155. Cost per case diagnosed ranged from $20-1,277. Cost-utility estimates ranged from cost-saving to $1846 per DALY averted. Higher cost-effectiveness estimates were associated with more expensive testing algorithms with increased support for linkage to care and post-test counseling. Conclusion: All studies considered HIVST cost-effective although major drivers were identified included underlying HIV prevalence, testing cost and linkage to care. HIVST is likely to be cost-effective in a LMIC context, however policy makers should be aware of the drivers of cost-effectiveness when implementing HIVST programs as these underlying factors can impact the overall cost-effectiveness of HIVST.

Development and Evaluation of a Digital HIV Risk Assessment Tool Incorporated Within an App-Based Self-Testing Program.

BACKGROUND: Low-risk perception is an important barrier to the utilization of HIV services. In this context, offering an online platform for people to assess their risk of HIV and inform their decision to test can be impactful in increasing testing uptake. Using secondary data from the HIVSmart! quasirandomized trial, we aimed to identify predictors of HIV, develop a risk staging model for South African township populations, and validate it in combination with the HIVSmart! digital self-testing program. SETTING: Townships in Cape Town, South Africa. METHODS: Using Bayesian predictive projection, we identified predictors of HIV and constructed a risk assessment model that we validated in external data. RESULTS: Our analyses included 3095 participants from the HIVSmart! trial. We identified a model of 5 predictors (being unmarried, HIV testing history, having had sex with a partner living with HIV, dwelling situation, and education) that performed best during external validation (area under the receiver operating characteristic curve, 89% credible intervals: 0.71, 0.68 to 0.72). The sensitivity of our HIV risk staging model was 91.0% (89.1% to 92.7%) and the specificity was 13.2% (8.5% to 19.8%) but increased when combined with a digital HIV self-testing program, the specificity was 91.6% (95.9% to 96.4%) and sensitivity remained similar at 90.9% (89.1% to 92.6%). CONCLUSIONS: This is the first validated digital HIV risk assessment tool developed for South African township populations and the first study to evaluate the added value of a risk assessment tool with an app-based HIV self-testing program. Study findings are relevant for application of digital programs to improve utilization of HIV testing services.

Self-sampling strategies (with/without digital innovations) in populations at risk of Chlamydia trachomatis and Neisseria gonorrhoeae: a systematic review and meta-analyses.

BACKGROUND: Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC) resulted in over 200 million new sexually transmitted infections last year. Self-sampling strategies alone or combined with digital innovations (ie, online, mobile or computing technologies supporting self-sampling) could improve screening methods. Evidence on all outcomes has not yet been synthesised, so we conducted a systematic review and meta-analysis to address this limitation. METHODS: We searched three databases (period: 1 January 2000-6 January 2023) for reports on self-sampling for CT/GC testing. Outcomes considered for inclusion were: accuracy, feasibility, patient-centred and impact (ie, changes in linkage to care, first-time testers, uptake, turnaround time or referrals attributable to self-sampling).We used bivariate regression models to meta-analyse accuracy measures from self-sampled CT/GC tests and obtain pooled sensitivity/specificity estimates. We assessed quality with Cochrane Risk of Bias Tool-2, Newcastle-Ottawa Scale and Quality Assessment of Diagnostic Accuracy Studies-2 tool. RESULTS: We summarised results from 45 studies reporting self-sampling alone (73.3%; 33 of 45) or combined with digital innovations (26.7%; 12 of 45) conducted in 10 high-income (HICs; n=34) and 8 low/middle-income countries (LMICs; n=11). 95.6% (43 of 45) were observational, while 4.4% (2 of 45) were randomised clinical trials.We noted that pooled sensitivity (n=13) for CT/GC was higher in extragenital self-sampling (>91.6% (86.0%-95.1%)) than in vaginal self-sampling (79.6% (62.1%-90.3%)), while pooled specificity remained high (>99.0% (98.2%-99.5%)).Participants found self-sampling highly acceptable (80.0%-100.0%; n=24), but preference varied (23.1%-83.0%; n=16).Self-sampling reached 51.0%-70.0% (n=3) of first-time testers and resulted in 89.0%-100.0% (n=3) linkages to care. Digital innovations led to 65.0%-92% engagement and 43.8%-57.1% kit return rates (n=3).Quality of studies varied. DISCUSSION: Self-sampling had mixed sensitivity, reached first-time testers and was accepted with high linkages to care. We recommend self-sampling for CT/GC in HICs but additional evaluations in LMICs. Digital innovations impacted engagement and may reduce disease burden in hard-to-reach populations. PROSPERO REGISTRATION NUMBER: CRD42021262950.

Socioeconomic factors impact the risk of HIV acquisition in the township population of South Africa: A Bayesian analysis.

With a prevalence almost twice as high as the national average, people living in South African townships are particularly impacted by the HIV epidemic. Yet, it remains unclear how socioeconomic factors impact the risk of HIV infection within township populations. Our objective was to estimate the extent to which socioeconomic factors (dwelling situation, education, employment status, and monthly income) explain the risk of HIV in South African township populations, after controlling for behavioural and individual risk factors. Using Bayesian logistic regression, we analysed secondary data from a quasi-randomised trial which recruited participants (N = 3095) from townships located across three subdistricts of Cape Town. We controlled for individual factors (age, sex, marital status, testing history, HIV exposure, comorbidities, and tuberculosis infection) and behavioural factors (unprotected sex, sex with multiple partners, with sex workers, with a partner living with HIV, under the influence of alcohol or drugs), and accounted for the uncertainty due to missing data through multiple imputation. We found that residing in informal dwellings and not having post-secondary education increased the odds of HIV (aOR, 89% CrI: 1.34, 1.07-1.68 and 1.82, 1.29-2.61, respectively), after controlling for subdistrict of residence, individual, and behavioural factors. Additionally, our results suggest different pathways for how socioeconomic status (SES) affect HIV infection in males and female participants: while socioeconomic factors associated with lower SES seem to be associated with a decreased likelihood of having recently sough HIV testing among male participants, they are associated with increased sexual risk taking which, among female participants, increase the risk of HIV. Our analyses demonstrate that social determinants of health are at the root of the HIV epidemic and affect the risk of HIV in multiple ways. These findings stress the need for the deployment of programs that specifically address social determinants of health.

Multiplexed rapid technologies for sexually transmitted infections: a systematic review.

Multiplexed technologies for sexually transmitted infections offer a convenient diagnostics option to screen, confirm, and treat multiple pathogens simultaneously. Due to scarce published real-world diagnostic performance data, we did a systematic review. Two reviewers searched major databases for data published between Jan 1, 2009, and April 20, 2020, and abstracted and analysed sensitivity and specificity data from 24 studies, which assessed 17 multiplex rapid nucleic acid amplification test platforms and seven multiplex immunochromatographic devices. Overall, these studies evaluated 19 sexually transmitted infections in 26 126 individuals. High sensitivity and specificity were shown for rapid nucleic acid amplification platform tests and immunochromatographic devices, with performance varying by pathogen, device, seropositivity, and subpopulation screened. As most devices yielded more than 95% sensitivity and specificity, immunochromatographic tests and rapid nucleic acid amplification test platforms can be advised for screening and confirmatory use. These highly accurate devices are appropriate for integrated, rapid screening initiatives for sexually transmitted infections to screen and treat many of these infections simultaneously, for antimicrobial stewardship, and for disease elimination programmes.

Prioritizing gender equity and intersectionality in Canadian global health institutions and partnerships.

Despite governmental efforts to close the gender gap and global calls including Sustainable Development Goal 5 to promote gender equality, the sobering reality is that gender inequities continue to persist in Canadian global health institutions. Moreover, from health to the economy, security to social protection, COVID-19 has exposed and heightened pre-existing inequities, with women, especially marginalized women, being disproportionately impacted. Women, particularly women who face bias along multiple identity dimensions, continue to be at risk of being excluded or delegitimized as participants in the global health workforce and continue to face barriers in career advancement to leadership, management and governance positions in Canada. These inequities have downstream effects on the policies and programmes, including global health efforts intended to support equitable partnerships with colleagues in low- and middle- income countries. We review current institutional gender inequities in Canadian global health research, policy and practice and by extension, our global partnerships. Informed by this review, we offer four priority actions for institutional leaders and managers to gender-transform Canadian global health institutions to accompany both the immediate response and longer-term recovery efforts of COVID-19. In particular, we call for the need for tracking indicators of gender parity within and across our institutions and in global health research (e.g., representation and participation, pay, promotions, training opportunities, unpaid care work), accountability and progressive action.

Global Health Facility-Based Interventions to Achieve UNAIDS 90-90-90: A Systematic Review and Narrative Analysis.

To evaluate whether health facility-based HIV interventions align with UNAIDS 90-90-90 targets, we performed a systematic review through the lens of UNAIDS targets. We searched 11 databases, retrieving 5201 citations with 26 eligible studies classified by country income and UNAIDS target. We analyzed whether reporting of study outcome metrics was in line with UNAIDS targets using a standardized extraction form and results were summarized in a narrative synthesis given data heterogeneity. We also assessed the quality of randomized trials with the Cochrane Risk of Bias Tool and observational studies with the Newcastle-Ottawa Scale. Stratification of interventions by country income level revealed themes in successful interventions that provide insight for scale-up in similar resource contexts. Few studies reported outcomes using metrics according to UNAIDS targets. Standardization of reporting according to the UNAIDS framework could facilitate comparability of interventions and inform country-level progress on an international scale.

Implementation of an electronic patient-reported measure of barriers to antiretroviral therapy adherence with the Opal patient portal: Protocol for a mixed method type 3 hybrid pilot study at a large Montreal HIV clinic.

BACKGROUND: Adherence to antiretroviral therapy (ART) remains problematic. Regular monitoring of its barriers is clinically recommended, however, patient-provider communication around adherence is often inadequate. Our team thus decided to develop a new electronically administered patient-reported outcome measure (PROM) of barriers to ART adherence (the I-Score) to systematically capture this data for physician consideration in routine HIV care. To prepare for a controlled definitive trial to test the I-Score intervention, a pilot study was designed. Its primary objectives are to evaluate patient and physician perceptions of the I-Score intervention and its implementation strategy. METHODS: This one-arm, 6-month study will adopt a mixed method type 3 implementation-effectiveness hybrid design and be conducted at the Chronic Viral Illness Service of the McGill University Health Centre (Montreal, Canada). Four HIV physicians and 32 of their HIV patients with known or suspected adherence problems will participate. The intervention will involve having patients complete the I-Score through a smartphone application (Opal), before meeting with their physician. Both patients and physicians will have access to the I-Score results, for consideration during the clinic visits at Times 1, 2 (3 months), and 3 (6 months). The implementation strategy will focus on stakeholder involvement, education, and training; promoting the intervention's adaptability; and hiring an Application Manager to facilitate implementation. Implementation, patient, and service outcomes will be collected (Times 1-2-3). The primary outcome is the intervention's acceptability to patients and physicians. Qualitative data obtained, in part, through physician focus groups (Times 2-3) and patient interviews (Times 2-3) will help evaluate the implementation strategy and inform any methodological adaptations. DISCUSSION: This study will help plan a definitive trial to test the efficacy of the I-Score intervention. It will generate needed data on electronic PROM interventions in routine HIV care that will help improve understanding of conditions for their successful implementation. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT04702412; https://clinicaltrials.gov/.

Impact of a personalised, digital, HIV self-testing app-based program on linkages and new infections in the township populations of South Africa.

INTRODUCTION: Implementation data for digital unsupervised HIV self-testing (HIVST) are sparse. We evaluated the impact of an app-based, personalised, oral HIVST program offered by healthcare workers in Western Cape, South Africa. METHODS: In a quasirandomised study (n=3095), we recruited consenting adults with undiagnosed HIV infection from township clinics. To the HIVST arm participants (n=1535), we offered a choice of an offsite (home, office or kiosk based), unsupervised digital HIVST program (n=962), or an onsite, clinic-based, supervised digital HIVST program (n=573) with 24/7 linkages services.With propensity score analyses, we compared outcomes (ie, linkages, new HIV infections and test referrals) with conventional HIV testing (ConvHT) arm participants (n=1560), recruited randomly from geographically separated clinics. RESULTS: In both arms, participants were young (HIVST vs ConvHT) (mean age: 28.2 years vs 29.2 years), female (65.0% vs 76.0%) and had monthly income <3000 rand (80.8% vs 75%).Participants chose unsupervised HIVST (62.7%) versus supervised HIVST and reported multiple sex partners (10.88% vs 8.7%), exposure to sex workers (1.4% vs 0.2%) and fewer comorbidities (0.9% vs 1.9%). Almost all HIVST participants were linked (unsupervised HIVST (99.7%), supervised HIVST (99.8%) vs ConvHT (98.5%)) (adj RR 1.012; 95% CI 1.005 to 1.018) with new HIV infections: overall HIVST (9%); supervised HIVST (10.9%) and unsupervised HIVST (7.6%) versus ConvHT (6.79%) (adj RR 1.305; 95% CI 1.023 to 1.665); test referrals: 16.7% HIVST versus 3.1% ConvHT (adj RR 5.435; 95% CI 4.024 to 7.340). CONCLUSIONS: Our flexible, personalised, app-based HIVST program, offered by healthcare workers, successfully linked almost all HIV self-testers, detected new infections and increased referrals to self-test. Data are relevant for digital HIVST initiatives worldwide.

HIV self-testing with digital supports as the new paradigm: A systematic review of global evidence (2010-2021).

BACKGROUND: HIV self-testing (HIVST) is recommended by the WHO as an innovative strategy to reach UNAIDS targets to end HIV by 2030. HIVST with digital supports is defined as the use of digital interventions (e.g., website-based, social media, mobile HIVST applications (apps), text messaging (SMS), digital vending machines (digital VMs)) to improve the efficiency and impact of HIVST. HIVST deployment and integration in health services is an emerging priority. We conducted a systematic review aiming to close the gap in evidence that summarizes the impact of digitally supported HIVST and to inform policy recommendations. METHODS: We searched PubMed and Embase for articles and abstracts on HIVST with digital supports published during the period February 1st, 2010 to June 15th, 2021, following Cochrane guidelines and PRISMA methodology. We assessed feasibility, acceptability, preference, and impact outcomes across all populations and study designs. Metrics reported were willingness to use HIVST, preferences for HIVST delivery, proportion of first-time testers, HIVST uptake, HIVST kit return rate, and linkage to care. Heterogeneity of the interventions and reported metrics precluded us from conducting a meta-analysis. FINDINGS: 46 studies were narratively synthesized, of which 72% were observational and 28% were RCTs. Half of all studies (54%, 25/46) assessed web-based innovations (e.g., study websites, videos, chatbots), followed by social media (26%, 12/46), HIVST-specific apps (7%, 3/46), SMS (9%, 4/46), and digital VMs (4%, 2/46). Web-based innovations were found to be acceptable (77-97%), preferred over in-person and hybrid options by more first-time testers (47-48%), highly feasible (93-95%), and were overall effective in supporting linkage to care (53-100%). Social media and app-based innovations also had high acceptability (87-95%) and linkage to care proportions (80-100%). SMS innovations increased kit return rates (54-94%) and HIVST uptake among hard-to-reach groups. Finally, digital VMs were highly acceptable (54-93%), and HIVST uptake was six times greater when using digital VMs compared to distribution by community workers. INTERPRETATION: HIVST with digital supports was deemed feasible, acceptable, preferable, and was shown to increase uptake, engage first-time testers and hard-to-reach populations, and successfully link participants to treatment. Findings pave the way for greater use of HIVST interventions with digital supports globally.

Multiplexed technologies for sexually transmitted infections: global evidence on patient-centered and clinical health outcomes.

INTRODUCTION: Conventional care packages around screening for sexually transmitted infections (STIs) entail multiple clinic visits and precipitate losses to follow-up. To prevent these losses, multiplexed technologies for STIs (immunochromatographic tests/devices/assays and molecular assays that can screen multiple pathogens or multiple strains of one STI) can yield same-day results in a single visit. Research evidence of patient-centred (preference, satisfaction) and clinical health outcomes (feasibility, case positivity, uptake, impact) has not been synthesised. We conducted a systematic review to fill this gap. METHODS: For the period 2009-2020, two independent reviewers searched PubMed and Embase, retrieved 4440 citations and abstracted data from 42 relevant studies. RESULTS: Of 42 studies, 10 (23.8%) evaluated multiplexed immunochromatographic and 32 (76.2%) molecular assays. Outcomes were reported as follows: preference (n=3), satisfaction (n=2), uptake (n=1), feasibility (n=2), case positivity (n=42) and impact (n=11). Screened populations included various at-risk groups. A majority (86.1%-92.4%) of participants preferred (60.2%-97.2%) multiplexed technologies (over conventional testing). Compared with conventional lab-based testing, test uptake improved by 99.4% (hepatitis C), 99.6% (Trichomonas vaginalis), 78.6% (hepatitis B) and 42.0% (HIV). Varying case positivities were documented depending on populations screened: HIV (1.8%-29.3%), hepatitis B (1.1%-23.9%), hepatitis C (0.5%-42.2%), Chlamydia trachomatis (2.8%-30.2%), Neisseria gonorrhoeae (0.0%-30.3%) and T. vaginalis (0.0%-32.7%). Regarding impact, 70.0%-100.0% of screened participants were linked to care, with result turnaround times ranging from 14 min (immunochromatographic assays) to 300 min (molecular assays). CONCLUSIONS: Compared with conventional lab-based testing, rapid multiplexed technologies were preferred by testees and led to quicker turnaround times for many STIs yielding same-day results thereby allowing to initiate rapid linkages to care. They were further shown to be highly feasible and impactful for detection and treatment facilitation. Based on these promising results, multiplexed technologies offer potential to screen at-risk populations to reduce onward STI transmission worldwide.

An observed, prospective field study to evaluate the performance and acceptance of a blood-based HIV self-test in Canada.

BACKGROUND: Self testing for HIV is a targeted intervention with the potential to increase the access, uptake and frequency of HIV testing and more effectively reach the undiagnosed, especially in priority populations. The objectives of this study were to (1) evaluate the INSTI HIV self-test performance compared with laboratory reference testing, (2) document if intended users can perform the steps to use the HIV self-test device, and (3) document if intended users can successfully interpret contrived positive, negative, and invalid results. Study was intended to be submitted to Health Canada for review for regulatory approval purposes. METHODS: The study used a cross-sectional design and recruited consenting adults who were representative of intended users of HIV self-testing from four community sites across Ontario, Québec, and Manitoba between August 2019 and March 2020. The results of the observed HIV self-test were compared with results of the Abbott Architect HIV Ag/Ab Combo test. Usability outcomes for critical (e.g., lancing finger, blood droplet into bottle, shaking bottle four times) and noncritical self-test procedure steps were also determined. RESULTS: Overall, 77% (n = 522) of participants were between 18 and 45 years of age, 61% (n = 410) were male, 71% (n = 480) had some college or more education, and 45% (n = 307) were employed; identity for race and ethnicity: Caucasian (44%; n = 296), African, Caribbean or Black (17%; n = 113), Indigenous [First Nations, Métis or Inuit] (14%; n = 95), Asian (16%; n = 106), Latin American (7%; n = 46). Primary performance analysis on 678 completed HIV self-tests revealed a positive percent agreement of 100% (5/5, 95% CI: 43.6-97.0%) and a negative percent agreement of 99.5% (614/617, 95% CI: 98.6-99.8%) with the comparator method. The overall percent agreement of results interpretation between participant and observer was 93.5% (n = 633). For the 708 participants who took part in the usability study, the average success rate for steps determined to be "critical" for successful completion of the test was 92.4%. 97% (n = 670) of participants found the instructions easy to follow, and 95% (n = 655) of participants indicated that they would use the test again. Of the 404 participants who interpreted the strong positive, weak positive, negative, and invalid contrived results, successful interpretation ranged from 90.6% (for weak positive, n = 366) to 99.3% (for negative, n = 401). CONCLUSIONS: The addition of a regulatory-approved self-test into the Canadian HIV testing landscape could significantly increase HIV testing rates. Having a blood-based HIV self-test approved in Canada can offer an accurate, acceptable, and simple alternative to facility-based HIV testing, particularly when impacted by Coronavirus pandemic restrictions.