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Biomedical subjects

Thomas Kerr

Publications and source records attributed to Thomas Kerr.

At least 19 recordsLinked to original sources
PubMed2007

Changes in injecting practices associated with the use of a medically supervised safer injection facility.

Injection drug users (IDUs) are vulnerable to serious health complications resulting from unsafe injection practices. We examined whether the use of a supervised safer injection facility (SIF) promoted change in injecting practices among a representative sample of 760 IDUs who use a SIF in Vancouver, Canada. Consistent SIF use was compared with inconsistent use on a number of self-reported changes in injecting practice variables. More consistent SIF use is associated with positive changes in injecting practices, including less reuse of syringes, use of sterile water, swabbing injection sites, cooking/filtering drugs, less rushed injections, safe syringe disposal and less public injecting.

Adult↗
PubMed2007

Factors associated with premature mortality among young injection drug users in Vancouver.

BACKGROUND: Young injection drug users (IDUs) may be at increased risk of premature mortality due to the health risks associated with injection drug use including overdoses and infections. However, there has been little research conducted on mortality causes, rates and associations among this population. We undertook this study to investigate patterns of premature mortality, prior to age 30 years, among young IDUs. METHODS: Since 1996, 572 young (< or = 29 years) IDUs have been enrolled in the Vancouver Injection Drug Users Study (VIDUS). Semi-annually, participants have completed an interviewer-administered questionnaire and have undergone serologic testing for HIV and hepatitis C (HCV). Mortality data have been continually updated through linkages with the Provincial Coroner's Office. Crude and age-specific mortality rates, standardized mortality ratios, and life expectancy measures were calculated using person-time methods. Predictors of mortality were identified using Cox regression analyses. FINDINGS: Twenty-two participants died prior to age 30 years during the follow-up period for an overall crude mortality rate of 1,368 per 100,000 person-years. Overall, young IDUs were 16.4 times (95% confidence interval [CI]; 9.1-27.1) more likely to die; young women IDUs were 54.1 times (95%CI; 29.6-90.8) and young men IDUs were 12.9 times (95%CI; 5.5, 25.3) more likely to die when compared to the Canadian non-IDU population of the same age. The leading observed cause of death among females was: homicide (N = 9); and among males: suicide (N = 3) and overdose (N = 3). In Cox regression analyses, factors associated with mortality were, HIV infection (Hazard Ratio [HR]: 4.55; CI: 1.92-10.80) and sex work (HR: 2.76; CI: 1.16-6.56). INTERPRETATION: Premature mortality was 13 and 54 times higher among young men and women who use injection drugs in Vancouver than among the general population in Canada. The majority of deaths among the women were attributable to homicide, suggesting that interventions should occur not only through harm reduction services but also through structural interventions at the legal and policy level.

Journal Article↗
PubMed2007

Rates of inappropriate antiretroviral prescription among injection drug users.

BACKGROUND: Although the survival benefits of antiretroviral therapy (ART) for the treatment of HIV infection are well established, the clinical management of HIV disease continues to present major challenges. There are particular concerns regarding access to appropriate HIV treatment among HIV-infected injection drug users (IDU). METHODS: In a prospective cohort study of HIV-infected IDU in Vancouver, Canada, we examined initial ART regimens vis-à-vis the provincial government's therapeutic guidelines at the time ART was initiated. Briefly, there have been four sets of guidelines: Era 1 (1992 to November 1995; double-drug (dual NRTIs) ART for patients with a CD4 cell count of 350 or less); Era 2 (December 1995 to May 1996; double-drug therapy for patients with a CD4+ cell count of 500 or less); Era 3 (June 1996 to June 1997; triple-drug therapy (dual NRTIs with a PI or NNRTI) for patients who had a plasma viral load of > 100,000 HIV-1 RNA copies/mL; dual therapy with two NRTIs for those with a plasma viral load of 5,000 to 100,000 HIV-1 RNA copies/mL); Era 4 (since July 1997; universal use of triple drug therapy as first-line treatment). RESULTS: Between May 1996 and May 2003, 431 HIV-infected individuals were enrolled into the cohort. By May 31, 2003, 291 (67.5%) individuals had initiated ART. We noted instances of inappropriate antiretroviral prescription in each guideline era, with 9 (53%) in Era 1, 3 (12%) in Era 2, 22 (28%) in Era 3, and 23 (15%) in Era 4. Of the 57 subjects who received an inappropriate ART regimen initially, 14 never received the appropriate therapy; among the remaining 43, the median time to the initiation of a guideline-appropriate ART regimen was 12 months (inter-quartile range 5-20). CONCLUSION: The present study identified measurable rates of guideline-inappropriate ART prescription for patients who were injection drug users. Rates were highest in the era of dual therapy, although high rates persisted into the triple-therapy era. As therapeutic guidelines continue to evolve, it is critical that mechanisms be put in place to ensure prescription of ART combinations for IDU that are consistent with current expert recommendations.

Journal Article↗
PubMed2006

HIV seroprevalence among participants at a Supervised Injection Facility in Vancouver, Canada: implications for prevention, care and treatment.

North America's first government sanctioned medically supervised injection facility (SIF) was opened during September 2003 in Vancouver, Canada. This was in response to a large open public drug scene, high rates of HIV and hepatitis C transmission, fatal drug overdoses, and poor health outcomes among the city's injection drug users. Between December 2003 and April 2005, a representative sample of 1,035 SIF participants were enrolled in a prospective cohort that required completing an interviewer-administered questionnaire and providing a blood sample for HIV testing. HIV infection was detected in 170/1007 (17%) participants and was associated with Aboriginal ethnicity (adjusted Odds Ratio [aOR], 2.70, 95% Confidence Interval [95% CI], 1.84-3.97), a history of borrowing used needles/syringes (aOR, 2.0, 95% CI, 1.37-2.93), previous incarceration (aOR, 1.87, 95% CI, 1.11-3.14), and daily injection cocaine use (aOR, 1.42, 95% CI, 1.00-2.03). The SIF has attracted a large number of marginalized injection drug users and presents an excellent opportunity to enhance HIV prevention through education, the provision of sterile injecting equipment, and a supervised environment to self-inject. In addition, the SIF is an important point of contact for HIV positive individuals who may not be participating in HIV care and treatment.

Journal Article↗
PubMed2006

Increasing use and associated harms of crystal methamphetamine injection in a Canadian setting.

BACKGROUND: There is a growing concern surrounding crystal methamphetamine use in Canada despite surprisingly little empirical data to support such claims. We evaluated the trends in crystal methamphetamine injection and factors associated with injection of the drug among a cohort of injection drug users (IDU) in Vancouver. METHODS: We conducted a prospective analysis of factors associated with crystal methamphetamine injection among participants enrolled in the Vancouver Injection Drug Users Study (VIDUS). Since serial measures for each individual were available, variables potentially associated with crystal methamphetamine injection were evaluated using generalized estimating equations (GEE) with logit link for binary outcomes. RESULTS: Overall, 1587 IDU were enrolled into the VIDUS cohort between May 1996 and December 2004. The proportion of IDU who reported injecting crystal methamphetamine during the last 6 months increased during the study period (Cochran-Armitage trend test, p<0.001). In multivariate GEE analyses, crystal methamphetamine injection was independently associated with younger age (adjusted odds ratio [AOR]: 4.77, 95% confidence interval [CI]=3.40-6.70), Caucasian ethnicity (AOR=2.21, 95% CI=1.57-3.12), syringe borrowing (AOR=1.62, 95% CI=1.22-2.13), and syringe lending (AOR=1.40, 95% CI=1.02-1.86). INTERPRETATION: There was a significant trend towards increasing crystal methamphetamine injection in this setting and elevated HIV risk behavior and younger age were independently associated with crystal methamphetamine injection. Given that banning precursor chemicals has had a limited effect on reducing methamphetamine supply in other jurisdictions, pragmatic and effective interventions are needed to address the growing use of this drug.

Adult↗
PubMed2006

Summary of findings from the evaluation of a pilot medically supervised safer injecting facility.

In many cities, infectious disease and overdose epidemics are occurring among illicit injection drug users (IDUs). To reduce these concerns, Vancouver opened a supervised safer injecting facility in September 2003. Within the facility, people inject pre-obtained illicit drugs under the supervision of medical staff. The program was granted a legal exemption by the Canadian government on the condition that a 3-year scientific evaluation of its impacts be conducted. In this review, we summarize the findings from evaluations in those 3 years, including characteristics of IDUs at the facility, public injection drug use and publicly discarded syringes, HIV risk behaviour, use of addiction treatment services and other community resources, and drug-related crime rates. Vancouver's safer injecting facility has been associated with an array of community and public health benefits without evidence of adverse impacts. These findings should be useful to other cities considering supervised injecting facilities and to governments considering regulating their use.

Acquired Immunodeficiency Syndrome↗
PubMed2006

Predictors of non-fatal overdose among a cohort of polysubstance-using injection drug users.

BACKGROUND: Non-fatal overdose is a major determinant of morbidity among injection drug users (IDU). We sought to evaluate factors associated with non-fatal overdose among IDU in Vancouver. METHODS: We examined non-fatal overdose among participants in the Vancouver Injection Drug Users Study. Correlates of non-fatal overdose occurring between 1996 and 2004 were identified using generalized estimating equations (GEE). RESULTS: There were 1587 participants included in this analysis, including 576 (36%) women. At baseline, 750 (47%) reported a history of non-fatal overdose. In total, 985 reports of non-fatal overdose were made during follow-up by 519 (32.7%) participants. In multivariate GEE analyses, factors independently associated with non-fatal overdose included: heroin injection (AOR=2.67), cocaine injection (AOR=2.01), benzodiazepine use (AOR=2.00), requiring help injecting (AOR=1.58), binge drug use (AOR=1.52), homelessness (AOR=1.38), alcohol use (AOR=1.32), street injecting (AOR=1.22), non-injectable opiate use (AOR=1.16), speedball use (AOR=1.15), and recent incarceration (AOR=1.14). Younger age (AOR=0.99) and methadone use (AOR=0.51) were protective. CONCLUSIONS: We found that non-fatal overdose was common among local IDU. Non-fatal overdose was associated with several factors that may be amenable to intervention, including opiate and stimulant use, and the characteristic of requiring help with injecting. These findings indicate the need for the ongoing development of structural interventions to address this common cause of morbidity among IDU.

Adolescent↗
PubMed2006

Injection drug users' perceptions regarding use of a medically supervised safer injecting facility.

BACKGROUND: In recent years, there has been increased interest in supervised safer injecting facilities (SIF) as a strategy to reduce the harms of illicit drug use; however, little work has been done to assess drug users' satisfaction with this service. This study was undertaken to explore injection drug users' experiences and opinions regarding North America's first SIF in Vancouver, Canada. METHODS: Injection drug users (IDU) were randomly recruited from within the Vancouver SIF and invited to enroll in the Scientific Evaluation of Supervised Injecting (SEOSI) cohort. For the present study, participants were then surveyed regarding their experiences and beliefs regarding the SIF. RESULTS: Of 1082 IDU surveyed, 809 (75%) reported that their injecting behavior had changed as a result of using the SIF. Among these individuals, 80% indicated that the SIF had resulted in less rushed injecting, 71% indicated that the SIF had led to less outdoor injecting and 56% reported less unsafe syringe disposal. The three most common features always or usually limiting IDU's use of the SIF were: travel to the SIF (12%), limited operating hours (7%), and waiting times to access the SIF (5%). When asked in what ways the SIF might be improved, the three most common suggestions were: longer hours of operation (53%), addition of a washroom (51%), and reduced waiting times (46%). CONCLUSIONS: Many IDU reported changes in their injecting behaviors that have important implications for community and public health. Addressing a number of programmatic issues related to operating hours and waiting times, and the provision of additional amenities within SIF, may help to further improve their impact.

Adult↗
PubMed2006

Reconsidering the public health failings of the criminal justice system: a reflection on the case of Scott Ortiz.

Throughout most of the world, the primary response to the health and social impacts of illicit drug use has been to intensify the enforcement of drug laws. The consequences of this policy approach include an unprecedented growth in prison populations and increasing concerns regarding drug-related harms within prisons and without, including increased risk of HIV and hepatitis C (HCV) infection. This has led to calls from public health and prisoner advocacy groups to prison authorities to improve health services available in the community and those available to prisoners. While considerable progress has been made with respect to the growing implementation of HIV and HCV prevention measures within some nations' prisons, the case of Scott Ortiz illuminates a new set of challenges for prisoners and their advocates as judges often have a faulty understanding of public health arguments and data. In this case we see one such instance where a judge acts in ways not rooted in sound public health evidence or practice to produce a perverse outcome that violates both sound medical and judicial objectives.

Editorial↗
PubMed2006

Neighborhood and HIV infection among IDU: place of residence independently predicts HIV infection among a cohort of injection drug users.

This study was undertaken to investigate geographic residence in Vancouver's Downtown Eastside (DTES), Canada's poorest urban neighborhood, as an environmental risk factor for HIV infection among a cohort of injection drug users. HIV incidence rates were examined using Kaplan-Meier methods, and Cox proportional hazards regression was used to determine independent risk factors for HIV seroconversion. After intensive multivariate adjustment, DTES residence remained an independent predictor of HIV seroconversion (relative hazard=2.0, 95% CI: 1.4-3.0, p<0.001). These findings indicate the need for a greater recognition among policy-makers of geographic location as a risk factor for HIV incidence in urban settings and the need for further research to determine why place contributes so greatly to HIV risk. The findings also mark a need for prevention interventions to be appropriately targeted towards high-risk neighborhoods.

Adult↗
PubMed2006

Evaluating methamphetamine use and risks of injection initiation among street youth: the ARYS study.

Many Canadian cities are experiencing ongoing infectious disease and overdose epidemics among injection drug users (IDU). These health concerns have recently been exacerbated by the increasing availability and use of methamphetamine. The challenges of reducing health-related harms among IDU have led to an increased recognition that strategies to prevent initiation into injection drug use must receive renewed focus. In an effort to better explore the factors that may protect against or facilitate entry into injection drug use, the At Risk Youth Study (ARYS) has recently been initiated in Vancouver, Canada. The local setting is unique due to the significant infrastructure that has been put in place to reduce HIV transmission among active IDU. The ARYS study will seek to examine the impact of these programs, if any, on non-injection drug users. In addition, Vancouver has been the site of widespread use of methamphetamine in general and has seen a substantial increase in the use of crystal methamphetamine among street youth. Hence, the ARYS cohort is well positioned to examine the harms associated with methamphetamine use, including its potential role in facilitating initiation into injection drug use. This paper provides some background on the epidemiology of illicit drug use among street youth in North America and outlines the methodology of ARYS, a prospective cohort study of street youth in Vancouver, Canada.

Journal Article↗
PubMed2006

Aboriginal status is a prognostic factor for mortality among antiretroviral naïve HIV-positive individuals first initiating HAART.

BACKGROUND: Although the impact of Aboriginal status on HIV incidence, HIV disease progression, and access to treatment has been investigated previously, little is known about the relationship between Aboriginal ethnicity and outcomes associated with highly active antiretroviral therapy (HAART). We undertook the present analysis to determine if Aboriginal and non-Aboriginal persons respond differently to HAART by measuring HIV plasma viral load response, CD4 cell response and time to all-cause mortality. METHODS: A population-based analysis of a cohort of antiretroviral therapy naïve HIV-positive Aboriginal men and women 18 years or older in British Columbia, Canada. Participants were antiretroviral therapy naïve, initiated triple combination therapy between August 1, 1996 and September 30, 1999. Participants had to complete a baseline questionnaire as well as have at least two follow-up CD4 and HIV plasma viral load measures. The primary endpoints were CD4 and HIV plasma viral load response and all cause mortality. Cox proportional hazards models were used to determine the association between Aboriginal status and CD4 cell response, HIV plasma viral load response and all-cause mortality while controlling for several confounder variables. RESULTS: A total of 622 participants met the study criteria. Aboriginal status was significantly associated with no AIDS diagnosis at baseline (p = 0.0296), having protease inhibitor in the first therapy (p = 0.0209), lower baseline HIV plasma viral load (p < 0.001), less experienced HIV physicians (P = 0.0133), history of IDU (p < 0.001), not completing high school (p = 0.0046), and an income of less than $10,000 per year (p = 0.0115). Cox proportional hazards models controlling for clinical characteristics found that Aboriginal status had an increased hazard of mortality (HR = 3.12, 95% CI: 1.77-5.48) but did not with HIV plasma viral load response (HR = 1.15, 95% CI: 0.89-1.48) or CD4 cell response (HR = 0.95, 95% CI: 0.73-1.23). CONCLUSION: Our study demonstrates that HIV-infected Aboriginal persons accessing HAART had similar HIV treatment response as non-Aboriginal persons but have a shorter survival. This study highlights the need for continued research on medical interventions and behavioural changes among HIV-infected Aboriginal and other marginalized populations.

Journal Article↗
PubMed2006

Impact of a medically supervised safer injecting facility on drug dealing and other drug-related crime.

North America's first medically supervised safer injecting facility (SIF) recently opened in Vancouver, Canada. One of the concerns prior to the SIF's opening was that the facility might lead to a migration of drug activity and an increase in drug-related crime. Therefore, we examined crime rates in the neighborhood where the SIF is located in the year before versus the year after the SIF opened. No increases were seen with respect to drug trafficking (124 vs. 116) or assaults/robbery (174 vs. 180), although a decline in vehicle break-ins/vehicle theft was observed (302 vs. 227). The SIF was not associated with increased drug trafficking or crimes commonly linked to drug use.

British Columbia↗
PubMed2006

Service uptake and characteristics of injection drug users utilizing North America's first medically supervised safer injecting facility.

In 2003, the city of Vancouver, British Columbia, opened North America's first government-sanctioned safer injecting facility, where injection drug users (IDUs) can inject preobtained illicit drugs under the supervision of nurses. Use of the service by IDUs was followed by measurable reductions in public drug use and syringe sharing. IDUs who are frequently using the program tend to be high-intensity cocaine and heroin injectors and homeless individuals. The facility has provided high-risk IDUs a hygienic space where syringe sharing can be eliminated and the risk of fatal overdose reduced. Ongoing evaluation will be required to assess its impact on overdose rates and HIV infection levels, as well as its ability to improve IDU contact with medical care and addiction treatment.

Ambulatory Care Facilities↗
PubMed2006

Antiretroviral adherence and HIV treatment outcomes among HIV/HCV co-infected injection drug users: the role of methadone maintenance therapy.

OBJECTIVE: We examined the association of methadone maintenance therapy (MMT) with highly active antiretroviral therapy (HAART) adherence and HIV treatment outcomes among a cohort of HIV/HCV co-infected injection drug users (IDUs). METHODS: We obtained demographic, drug use, and addiction care history from the Vancouver Injection Drug User Study (VIDUS), which is an open cohort study of IDUs. The questionnaires were longitudinally linked to the British Columbia HIV/AIDS Drug Treatment Program to obtain HAART adherence and HIV treatment outcome data. There were 278 VIDUS participants who accessed HAART from August 1, 1996 to November 24, 2003. We constructed longitudinal logistic models using generalized estimating equations to examine the independent associations between methadone maintenance therapy and the following outcomes: HAART adherence; plasma HIV-1 RNA suppression; and CD4 cell rise of 100cells/mm(3). RESULTS: Among participants who reported at least weekly heroin use, MMT was independently associated with lower odds of subsequent weekly heroin use during the follow-up period (adjusted odds ratio; 95% confidence interval [AOR; 95% CI]: 0.24; 0.14-0.40). We also found that MMT was positively associated with adherence (AOR 1.52; 95% CI 1.16-2.00), HIV-1 RNA suppression (AOR 1.34; 95% CI 1.00-1.79), and CD4 cell count rise (AOR 1.58; 95% CI 1.26-1.99). CONCLUSIONS: Among HIV/HCV co-infected IDUs on HAART, enrollment in MMT was associated with reduced heroin use, and improved adherence, HIV-1 RNA suppression and CD4 cell count response. Integrating opiate addiction care and HIV care may provide improved health outcomes for this vulnerable population and should be further explored.

Adult↗