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1.  Predictors of unstructured antiretroviral treatment interruption and resumption among HIV-positive individuals in Canada 
HIV medicine  2014;16(2):76-87.
Sustained optimal use of combination antiretroviral treatment (cART) has been shown to decrease morbidity, mortality and HIV transmission. However, incomplete adherence and treatment interruption (TI) remain challenges to the full realization of the promise of cART. We estimated trends and predictors of treatment interruption and resumption among individuals in the Canadian Observational Cohort (CANOC) collaboration.
cART-naïve individuals ≥18 years of age who initiated cART between 2000–2011 were included. We defined TIs as ≥90 consecutive days off cART. We used descriptive analyses to study TI trends over time and Cox regression to identify factors predicting time to first TI and time to treatment resumption after a first TI.
7,633 participants were eligible, of whom 1,860 (24.5%) experienced a TI. The prevalence of TI in the first calendar year of cART decreased by half over the study period. Our analyses highlighted a higher risk of TI among women (adjusted hazard ratio (aHR): 1.59, 95%CI: 1.33–1.92), younger individuals (aHR: 1.27, 95%CI: 1.15–1.37 per decade increase), earlier treatment initiators (CD4 count ≥350 versus <200 mm3, aHR: 1.46, 95%CI: 1.17–1.81), Aboriginal participants (aHR: 1.67, 95%CI: 1.27–2.20), injecting drug users (aHR: 1.43, 95%CI: 1.09–1.89), and users of zidovudine versus tenofovir in the initial cART regimen (aHR: 2.47, 95%CI: 1.92–3.20). Conversely, factors predicting treatment resumption were male sex, older age, and a CD4 cell count <200 mm3 at cART initiation.
Despite significant improvements in cART since its advent, our results demonstrate that TIs remain relatively prevalent. Strategies to support continuous HIV treatment are needed to maximize the benefits of cART.
PMCID: PMC4300259  PMID: 25174373
Treatment interruption; HIV; antiretroviral therapy; retention; Canada
2.  Antiretroviral therapy is not associated with reduced herpes simplex virus shedding in HIV coinfected adults: an observational cohort study 
BMJ Open  2014;4(1):e004210.
Herpes simplex virus types 1 and 2 (HSV-1/2) may have adverse consequences on HIV type 1 infection. We quantified the frequency of HSV reactivations in highly active antiretroviral therapy (HAART)-treated adults with HIV, and compared it with that in HAART-naïve patients.
2 academic hospital sites in Toronto, Canada.
Asymptomatic HAART-naive (n=44) or treated (with HIV RNA <50 copies/mL, n=41) adults with HSV-1 and/or 2, HIV coinfection.
Outcome measures
HSV-1 and HSV-2 shedding as measured by PCR on oral, genital and anal swabs self-collected daily for 28 days.
Of the 85 participants, 88%, 67% and 53% were coinfected with HSV-1, HSV-2 and both HSV types, respectively. Median (IQR) CD4 count was 516 (382, 655) cells/mm3. HSV (type 1 and/or 2) shedding occurred on a median (IQR) of 7.1% (0, 17.9%) of days in HAART users and 3.6% (0, 10.7%) of days in non-HAART users. No significant relationship was observed between HAART and HSV-1/2 shedding in univariable (OR=1.55, 95% CI 0.83 to 2.87) or multivariable negative binomial models adjusted for sex, baseline CD4 count, recent immigrant status and time since HIV diagnosis (adjusted OR, aOR=1.05, 95% CI 0.43 to 2.58). Similar null results were observed for HSV-2 shedding in HSV-2 seropositive participants (aOR=1.16, 95% CI 0.40 to 3.36) and HSV-1 shedding in HSV-1 seropositive participants (aOR=0.70, 95% CI 0.14 to 3.47).
HSV reactivations persist despite suppressive HAART among adults coinfected with HSV and HIV. Clinical trials of suppressive anti-HSV therapy are warranted in this population.
PMCID: PMC3902380  PMID: 24464523
Virology; Sexual Medicine
3.  Gender Differences in Clinical Outcomes among HIV-Positive Individuals on Antiretroviral Therapy in Canada: A Multisite Cohort Study 
PLoS ONE  2013;8(12):e83649.
Cohort data examining differences by gender in clinical responses to combination antiretroviral therapy (ART) remain inconsistent and have yet to be explored in a multi-province Canadian setting. This study investigates gender differences by injection drug use (IDU) history in virologic responses to ART and mortality.
Data from the Canadian Observational Cohort (CANOC) collaboration, a multisite cohort study of HIV-positive individuals initiating ART after January 1, 2000, were included. This analysis was restricted to participants with a follow-up HIV-RNA plasma viral load measure and known IDU history. Weibull hazard regression evaluated time to virologic suppression (2 consecutive measures <50 copies/mL), rebound (>1000 copies/mL after suppression), and all-cause mortality. Sensitivity analyses explored the impact of presumed ART use in pregnancy on virologic outcomes.
At baseline, women (1120 of 5442 participants) were younger (median 36 vs. 41 years) and more frequently reported IDU history (43.5% vs. 28.8%) (both p<0.001). Irrespective of IDU history, in adjusted multivariable analyses women were significantly less likely to virologically suppress after ART initiation and were at increased risk of viral load rebound. In adjusted time to death analysis, no differences by gender were noted. After adjusting for presumed ART use in pregnancy, observed gender differences in time to virologic suppression for non-IDU, and time to virologic rebound for IDU, became insignificant.
HIV-positive women in CANOC are at heightened risk for poor clinical outcomes. Further understanding of the intersections between gender and other factors augmenting risk is needed to maximize the benefits of ART.
PMCID: PMC3877405  PMID: 24391803
4.  A Meta-Analysis of Six Placebo-Controlled Trials of Thiazolidinedione Therapy for HIV Lipoatrophy 
HIV clinical trials  2010;11(1):39-50.
PMCID: PMC3733492  PMID: 20400410
Meta-analysis; Rosiglitazone/Pioglitazone; Lipoatrophy; HIV; HAART
5.  Gender and Ethnicity Differences in HIV-related Stigma Experienced by People Living with HIV in Ontario, Canada 
PLoS ONE  2012;7(12):e48168.
This study aimed to understand gender and ethnicity differences in HIV-related stigma experienced by 1026 HIV-positive individuals living in Ontario, Canada that were enrolled in the OHTN Cohort Study. Total and subscale HIV-related stigma scores were measured using the revised HIV-related Stigma Scale. Correlates of total stigma scores were assessed in univariate and multivariate linear regression. Women had significantly higher total and subscale stigma scores than men (total, median = 56.0 vs. 48.0, p<0.0001). Among men and women, Black individuals had the highest, Aboriginal and Asian/Latin-American/Unspecified people intermediate, and White individuals the lowest total stigma scores. The gender-ethnicity interaction term was significant in multivariate analysis: Black women and Asian/Latin-American/Unspecified men reported the highest HIV-related stigma scores. Gender and ethnicity differences in HIV-related stigma were identified in our cohort. Findings suggest differing approaches may be required to address HIV-related stigma based on gender and ethnicity; and such strategies should challenge racist and sexist stereotypes.
PMCID: PMC3531426  PMID: 23300514
6.  Desires, Need, Perceptions, and Knowledge of Assisted Reproductive Technologies of HIV-Positive Women of Reproductive Age in Ontario, Canada 
ISRN Obstetrics and Gynecology  2012;2012:853503.
The purpose of this cross-sectional study is to assess the desire, need, perceptions, and knowledge of assisted reproductive technologies (ARTs) for women living with HIV (WLWHIV) and determine correlates of ART knowledge desire. WLWHIV of reproductive age were surveyed using the survey instrument “The HIV Pregnancy Planning Questionnaire” at HIV/AIDS service organizations across Ontario, Canada. Of our cohort of 500 WLWHIV, median age was 38, 88% were previously pregnant, 78% desired more information regarding ART, 59% were open to the idea of receiving ART, 39% felt they could access a sperm bank, and 17% had difficulties conceiving (self-reported). Age, African ethnicity, and residence in an urban center were correlated with desire for more ART information. Of participants, 50% wanted to speak to an obstetrician/gynecologist regarding pregnancy planning, and 74% regarded physicians as a main source of fertility service information. While the majority of participants in our cohort desire access to ART information, most do not perceive these services as readily accessible. Healthcare practitioners were viewed as main sources of information regarding fertility services and need to provide accurate information regarding access. Fertility service professionals need to be aware of the increasing demand for ART among WLWHIV.
PMCID: PMC3431126  PMID: 22957265
7.  Can herpes simplex virus type 2 suppression slow HIV disease progression: a study protocol for the VALacyclovir In Delaying Antiretroviral Treatment Entry (VALIDATE) trial 
Trials  2010;11:113.
Although highly active antiretroviral therapy (HAART) has dramatically decreased HIV-related morbidity and mortality, the associated costs, toxicities, and resistance risks make the potential delay of HAART initiation an attractive goal. Suppression of herpes simplex virus type 2 (HSV-2) may be a novel strategy for achieving this goal because HSV-2 is associated with clinically significant increases in HIV viral load, the primary driver of HIV disease progression.
The VALacyclovir In Delaying Antiretroviral Treatment Entry (VALIDATE) trial is a multicentre, randomized, fully blinded, clinical trial of twice daily valacyclovir 500 mg versus placebo for delaying the need for initiating HAART among HIV-1, HSV-2 co-infected HAART-naïve adults. 480 participants from Canada, Brazil and Argentina will undergo quarterly clinical follow-up until reaching the composite primary endpoint of having a CD4+ T-cell count ≤ 350 cells/mm3 or initiation of HAART for any reason, whichever occurs first. The primary analysis will use a proportional hazards model, stratified by site, to estimate the relative risk of progression to this endpoint associated with valacyclovir. Secondary analyses will compare the rates of change in CD4 count, median log10 HIV viral load, drug-related adverse events, frequency of HSV reactivations, rate of acyclovir-resistant HSV, and quality of life between study arms.
Although HIV treatment guidelines continue to evolve, with some authorities recommending earlier HAART among asymptomatic individuals, the potential delay of HAART remains a clinically relevant goal for many. If shown to be of benefit, implementation of the VALIDATE intervention will require careful consideration of both individual patient-level and public health implications.
Trial Registration
Current Controlled Trials ISRCTN66756285 NCT00860977
PMCID: PMC3002348  PMID: 21106086
8.  Economic Appraisal of Ontario's Universal Influenza Immunization Program: A Cost-Utility Analysis 
PLoS Medicine  2010;7(4):e1000256.
Beate Sander and colleagues assess the cost-effectiveness of the program that provides free seasonal influenza vaccines to the entire population of Ontario, Canada.
In July 2000, the province of Ontario, Canada, initiated a universal influenza immunization program (UIIP) to provide free seasonal influenza vaccines for the entire population. This is the first large-scale program of its kind worldwide. The objective of this study was to conduct an economic appraisal of Ontario's UIIP compared to a targeted influenza immunization program (TIIP).
Methods and Findings
A cost-utility analysis using Ontario health administrative data was performed. The study was informed by a companion ecological study comparing physician visits, emergency department visits, hospitalizations, and deaths between 1997 and 2004 in Ontario and nine other Canadian provinces offering targeted immunization programs. The relative change estimates from pre-2000 to post-2000 as observed in other provinces were applied to pre-UIIP Ontario event rates to calculate the expected number of events had Ontario continued to offer targeted immunization. Main outcome measures were quality-adjusted life years (QALYs), costs in 2006 Canadian dollars, and incremental cost-utility ratios (incremental cost per QALY gained). Program and other costs were drawn from Ontario sources. Utility weights were obtained from the literature. The incremental cost of the program per QALY gained was calculated from the health care payer perspective. Ontario's UIIP costs approximately twice as much as a targeted program but reduces influenza cases by 61% and mortality by 28%, saving an estimated 1,134 QALYs per season overall. Reducing influenza cases decreases health care services cost by 52%. Most cost savings can be attributed to hospitalizations avoided. The incremental cost-effectiveness ratio is Can$10,797/QALY gained. Results are most sensitive to immunization cost and number of deaths averted.
Universal immunization against seasonal influenza was estimated to be an economically attractive intervention.
Please see later in the article for the Editors' Summary
Editors' Summary
Annual outbreaks (epidemics) of influenza—a viral disease of the nose, throat, and airways—make millions of people ill and kill about 500,000 individuals every year. In doing so, they impose a considerable economic burden on society in terms of health care costs and lost productivity. Influenza epidemics occur because small but frequent changes in the viral proteins to which the immune system responds mean that an immune response produced one year by exposure to an influenza virus provides only partial protection against influenza the next year. Annual immunization with a vaccine that contains killed influenza viruses of the major circulating strains can boost this natural immunity and greatly reduce a person's chances of catching influenza. Consequently, many countries run seasonal influenza vaccine programs. These programs usually target people at high risk of complications from influenza and individuals likely to come into close contact with them, and people who provide essential community services. So, for example, in most Canadian provinces, targeted influenza immunization programs (TIIPs) offer free influenza vaccinations to people aged 65 years or older, to people with chronic medical conditions, and to health care workers.
Why Was This Study Done?
Some experts argue, however, that universal vaccination might provide populations with better protection from influenza. In 2000, the province of Ontario in Canada decided, therefore, to introduce a universal influenza immunization program (UIIP) to provide free influenza vaccination to everyone older than 6 months, the first large program of this kind in the world. A study published in 2008 showed that, following the introduction of the UIIP, vaccination rates in Ontario increased more than in other Canadian provinces. In addition, deaths from influenza and influenza-related use of health care facilities decreased more in Ontario than in provinces that continued to offer a TIIP. But is universal influenza vaccination good value for money? In this study, the researchers evaluate the cost-effectiveness of the Ontario UIIP by comparing the health outcomes and costs associated with its introduction with the health outcomes and costs associated with a hypothetical continuation of targeted influenza immunization.
What Did the Researchers Do and Find?
The researchers used data on TIIP and UIIP vaccine uptake, physician visits, emergency department visits, hospitalizations for influenza, and deaths from influenza between 1997 and 2004 in Ontario and in nine Canadian states offering TIIPs, and Ontario cost data, in their “cost-utility” analysis. This type of analysis estimates the additional cost required to generate a year of perfect health (a quality-adjusted life-year or QALY) through the introduction of an intervention. QALYs are calculated by multiplying the time spent in a certain health state by a measure of the quality of that health state. The researchers report that the cost of Ontario's UIIP was about twice as much as the cost of a TIIP for the province. However, the introduction of the UIIP reduced the number of influenza cases by nearly two-thirds and reduced deaths from influenza by more than a quarter compared with what would have been expected had the province continued to offer a TIIP, an overall saving of 1,134 QALYs. Furthermore, the reduction in influenza cases halved influenza-related health care costs, mainly because of reductions in hospitalization. Overall, this means that the additional cost to Ontario of saving one QALY through the introduction of the UIIP was Can$10,797, an “incremental cost-effectiveness ratio” of $10,797 per QALY gained.
What Do These Findings Mean?
In Canada, an intervention is considered cost-effective from the point of view of a health care purchaser if it costs less than Canadian $50,000 to gain one QALY. These findings indicate, therefore, that for Ontario the introduction of the UIIP is economically attractive. Indeed, the researchers calculate that even if the costs of the UIIP were to double, the additional cost of saving one QALY by introducing universal immunization would remain below $50,000. Other “sensitivity” analyses undertaken by the researchers also indicate that universal immunization is likely to be effective and cost-effective in Ontario if other key assumptions and/or data included in the calculations are varied within reasonable limits. Given these findings, the researchers suggest that a UIIP might be an appealing intervention in other Canadian provinces and in other high-income countries where influenza transmission and health-care costs are broadly similar to those in Ontario.
Additional Information
Please access these Web sites via the online version of this summary at
A PLoS Medicine Research Article by Kwong and colleagues describes how the introduction of universal influenza immunization in Ontario altered influenza-related health care use and deaths in the province
Wikipedia pages are available on QALYs and on cost-utility analysis (note that Wikipedia is a free online encyclopedia that anyone can edit; available in several languages)
Bandolier, an independent online journal about evidence-based health-care, provides information about QALYs and their use in cost-utility analysis
The UK National Institute for Health and Clinical Excellence has a webpage on Measuring effectiveness and cost-effectiveness: the QALY
PMCID: PMC2850382  PMID: 20386727
9.  Regional differences in rates of HIV-1 viral load monitoring in Canada: Insights and implications for antiretroviral care in high income countries 
Viral load (VL) monitoring is an essential component of the care of HIV positive individuals. Rates of VL monitoring have been shown to vary by HIV risk factor and clinical characteristics. The objective of this study was to determine whether there are differences among regions in Canada in the rates of VL testing of HIV-positive individuals on combination antiretroviral therapy (cART), where the testing is available without financial barriers under the coverage of provincial health insurance programs.
The Canadian Observational Cohort (CANOC) is a collaboration of nine Canadian cohorts of HIV-positive individuals who initiated cART after January 1, 2000. The study included participants with at least one year of follow-up. Generalized Estimating Equation (GEE) regression models were used to determine the effect of geographic region on (1) the occurrence of an interval of 9 months or more between two consecutive recorded VL tests and (2) the number of days between VL tests, after adjusting for demographic and clinical covariates. Overall and regional annual rates of VL testing were also reported.
3,648 individuals were included in the analysis with a median follow-up of 42.9 months and a median of 15 VL tests. In multivariable GEE logistic regression models, gaps in VL testing >9 months were more likely in Quebec (Odds Ratio (OR) = 1.72, p < 0.0001) and Ontario (OR = 1.78, p < 0.0001) than in British Columbia and among injection drug users (OR = 1.68, p < 0.0001) and were less likely among older individuals (OR = 0.77 per 10 years, p < 0.0001), among men having sex with men (OR = 0.62, p < 0.0001), within the first year of cART (OR = 0.15, p < 0.0001), among individuals on cART at the time of the blood draw (OR = 0.34, p < 0.0001) and among individuals with VL < 50 copies/ml at the previous visit (OR = 0.56, p < .0001).
Significant variation in rates of VL testing and the probability of a significant gap in testing were related to geographic region, HIV risk factor, age, year of cART initiation, type of cART regimen, being in the first year of cART, AIDS-defining illness and whether or not the previous VL was below the limit of detection.
PMCID: PMC2844400  PMID: 20184766
10.  Fertility Desires and Intentions of HIV-Positive Women of Reproductive Age in Ontario, Canada: A Cross-Sectional Study 
PLoS ONE  2009;4(12):e7925.
Improvements in life expectancy and quality of life for HIV-positive women coupled with reduced vertical transmission will likely lead numerous HIV-positive women to consider becoming pregnant. In order to clarify the demand, and aid with appropriate health services planning for this population, our study aims to assess the fertility desires and intentions of HIV-positive women of reproductive age living in Ontario, Canada.
Methodology/Principal Findings
A cross-sectional study with recruitment stratified to match the geographic distribution of HIV-positive women of reproductive age (18–52) living in Ontario was carried out. Women were recruited from 38 sites between October 2007 and April 2009 and invited to complete a 189-item self-administered survey entitled “The HIV Pregnancy Planning Questionnaire” designed to assess fertility desires, intentions and actions. Logistic regression models were fit to calculate unadjusted and adjusted odds ratios of significant predictors of fertility intentions. The median age of the 490 participating HIV-positive women was 38 (IQR, 32–43) and 61%, 52%, 47% and 74% were born outside of Canada, living in Toronto, of African ethnicity and currently on antiretroviral therapy, respectively. Of total respondents, 69% (95% CI, 64%–73%) desired to give birth and 57% (95% CI, 53%–62%) intended to give birth in the future. In the multivariable model, the significant predictors of fertility intentions were: younger age (age<40) (p<0.0001), African ethnicity (p<0.0001), living in Toronto (p = 0.002), and a lower number of lifetime births (p = 0.02).
The proportions of HIV-positive women of reproductive age living in Ontario desiring and intending pregnancy were higher than reported in earlier North American studies. Proportions were more similar to those reported from African populations. Healthcare providers and policy makers need to consider increasing services and support for pregnancy planning for HIV-positive women. This may be particularly significant in jurisdictions with high levels of African immigration.
PMCID: PMC2785467  PMID: 19997556
11.  A study of provider-caregiver communication in paediatric ambulatory care 
Paediatrics & Child Health  2006;11(4):217-221.
Provider-caregiver communication is a key ingredient in quality health care and patient safety, and effective communication has been shown to affect compliance and outcomes.
To identify and compare communication issues among three paediatric outpatient clinics.
In this prospective, qualitative study, a questionnaire was used to survey physicians, nurse practitioners and caregivers at three different infectious diseases clinics.
There was a statistically significant preponderance of families in the tuberculosis clinic for whom English was not the mother tongue and who were not fluent in English. Patients in the HIV clinic were less likely to be at their first appointment than were patients attending the other clinics. Patients in the general clinic were less likely to have been seen by the same physician on the previous visit. Parents from all three clinics were satisfied with the care they received, with communication and with rapport with their child. There was a trend toward parents in the tuberculosis clinic being happier with their clinic visit and less likely to complain about the wait time.
Language proficiency and lack of continuity of provider care were identified as potential risks for patient safety in the ambulatory setting. Further studies are necessary to identify language and cultural issues that may affect patient care in a tertiary paediatric hospital servicing a multiethnic population.
PMCID: PMC2528606  PMID: 19030275
Ambulatory care; Communication; Patient safety

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