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Biomedical subjects

Martin T Schechter

Publications and source records attributed to Martin T Schechter.

At least 37 records · Page 2Linked to original sources
PubMed2004

Rationale for evaluating North America's first medically supervised safer-injecting facility.

Many cities throughout the world are experiencing ongoing infectious disease and overdose epidemics among illicit injection drug users (IDUs). In particular, HIV and hepatitis C virus (HCV) have become endemic in many settings and bacterial infections, such as endocarditis, have become extremely common among this population. In an effort to reduce these public health concerns, in September 2003, Vancouver, Canada, opened a pilot medically supervised safer- injecting facility (SIF), where IDUs can inject pre-obtained illicit drugs under the supervision of medical staff. Before and since the facility's opening, there has been a substantial misunderstanding about the rationale for evaluating SIF as a public-health strategy. This article outlines the evidence and rationale in support of the Canadian initiative. This rationale involves limitations in conventionally applied drug-control efforts, and gaps in current public-health policies in controlling the spread of infectious diseases, and the incidence of overdose among IDUs.

British Columbia↗
PubMed2004

Sexual risk profile of young men in Vancouver, British Columbia, who have sex with men and inject drugs.

We compared sexual risk behaviors of men who have sex with men and inject drugs (MSM/IDU) with those of other men who have sex with men (MSM). Of 910 MSM surveyed, 106 (12%) injected drugs in the previous year. MSM/IDU were younger than MSM and more likely to be HIV-seropositive, Aboriginal, economically disadvantaged, engaged in the trade of sex for money or drugs, and to report having female sexual partners. MSM/IDU reported more casual sexual partners and in multivariate analyses were twice as likely to report unprotected receptive anal intercourse with casual partners. These results, combined with those from previous analyses, suggest that the higher risk for HIV seroconversion among MSM/IDU in this cohort is attributable mainly to sexual rather than injection-related exposures. Controlled assessments are needed to identify optimal sexual risk reduction strategies for MSM/IDU.

Adult↗
PubMed2004

Implications of the age range in a population-based BRCA1 testing program with eligibility based on family history of breast and ovarian cancer.

The current options available to BRCA1 mutation carriers can be classified as either cancer risk reduction or increased disease surveillance. Risk reduction might be preferable to young women. Increased surveillance might be more attractive to women when their cancer risk is highest. The aim of this report is to estimate the sensitivity, specificity and ability to detect carriers for a population-based BRCA1 testing program with eligibility based on family history of cancer, and examine the effect of age on the program's performance. A computer model was used to simulate the incidence of breast and ovarian cancer in a woman's family, based on her BRCA1 mutation carrier status. Age-specific estimates of the sensitivity and specificity for family history as an indicator of mutation status were applied to local population figures. Sensitivity of the program increased with the age of the proband and the size of her family. Sensitivity ranged from 0.33 for 20-year-olds with small families, to 0.98 for 60-year-olds with large families. Specificity was greater than 0.95, regardless of a woman's age or family size. If 0.12% of people carry a BRCA1 mutation, a province-wide testing program for people aged 20-69 with referrals based only on family history would have a sensitivity of 0.55. Only 2% of the genetic test results would be positive. The acceptability of a genetic testing program depends on its sensitivity and specificity, and on the options available to women who are found to carry a mutation. Compared with variation due to family size, the program sensitivity and specificity does not differ substantially amongst the various age groups.

Adult↗
PubMed2004

The cost of inaction on HIV transmission among injection drug users and the potential for effective interventions.

Estimated and potential medical costs of treating patients infected with human immunodeficiency virus (HIV) in urban areas of high HIV prevalence have not been well defined. We estimated the total medical cost of HIV disease among injection drug users in Vancouver, British Columbia, Canada, assuming stable and increasing HIV prevalence. Total medical costs were estimated by multiplying the average lifetime medical cost per person by the number of HIV-infected individuals. We assumed the cost of each HIV infection to be 150,000 Canadian dollars, based on empirical data, and HIV prevalence estimates were derived from the Vancouver Injection Drug Users Study (VIDUS) and external data sources. By use of Monte Carlo simulation methodology, we performed sensitivity analyses to estimate total medical cost, assuming the HIV prevalence remained stable at 31% and under a scenario in which the prevalence rose to 50%. Expected medical expenditures based on current HIV prevalence levels were estimated as 215,852,613 Canadian dollars. If prevalence rises to 50% as reported in other urban centers, the median estimated medical cost would be approximately 348,935,865 Canadian dollars. This represents a difference in the total costs between the two scenarios of 133,083,253 Canadian dollars. Health planners should consider that predicted medical expenditures related to the HIV epidemic among injection drug users in our setting may cost an estimated 215,852,613 Canadian dollars. If funding cannot be found for appropriate prevention interventions and the prevalence rises to 50%, a further 133,083,253 Canadian dollars may be required.

British Columbia↗
PubMed2004

Adherence to antiretroviral therapy and CD4 T-cell count responses among HIV-infected injection drug users.

OBJECTIVE: To evaluate the time to CD4 cell count response (> or = 50 cells/mm3) among patients initiating highly active antiretroviral therapy (HAART) with and without a history of injection drug use, and to examine the potential role of non-adherence to HAART on differential CD4 responses. METHODS: Population-based analysis of treatment-naive patients initiating HAART during the period 1 August 1996 to 31 July 2000 and who were followed until 31 March 2002. Patients were stratified based on 95% adherence and history of injection drug use, and Kaplan-Meier methods and Cox regression were used to evaluate CD4 response rates and factors associated with CD4 responses. RESULTS: Overall, the CD4 cell count response rate was slower among injection drug users in Kaplan-Meier analyses (log-rank: P<0.05). However, no differences existed when the analyses were restricted to adherent patients (log-rank: P=0.349). Similarly, the differences in the time to CD4 cell count response observed in univariate Cox regression analyses for patients with a history of injection drug use [relative hazard: 0.85 (95% CI: 0.75-0.97)] diminished after adjustment for adherence [adjusted relative hazard: 1.02 (95% CI: 0.89-1.16)]. CONCLUSION: These data demonstrate the importance of adherence on CD4 cell count responses and highlight the need for interventions to improve antiretroviral adherence among injection drug user.

Adult↗
PubMed2003

Prevalence and correlates of untreated human immunodeficiency virus type 1 infection among persons who have died in the era of modern antiretroviral therapy.

We evaluated all human immunodeficiency virus (HIV)-related deaths over the period 1 January 1995-31 December 2001 in a Canadian province in which all HIV care and antiretroviral therapy are provided free of charge. Persons who had received antiretroviral drugs before death were compared with those who had died without ever receiving HIV treatment, by fitting a logistic model. Overall, 1239 deaths were attributed to HIV infection during the study period. Of these, 406 (32.8%) occurred among persons who had never received any HIV treatment. In adjusted analyses, aboriginal ethnicity, female sex, and lower median income were negatively associated with receiving HIV treatment before death. Furthermore, among the 833 individuals who received treatment before death, only 379 (45.5%) received antiretroviral medication >or=75% of the time during their first year receiving therapy. The data demonstrate the need for novel interventions to expand HIV care to specific populations.

Anti-HIV Agents↗
PubMed2003

Adherence and plasma HIV RNA responses to highly active antiretroviral therapy among HIV-1 infected injection drug users.

BACKGROUND: The benefits of highly active antiretroviral therapy (HAART) for the treatment of HIV infection are well documented, but concerns regarding access and adherence to HAART are growing. We evaluated virological responses to HAART among HIV-1 infected patients who were injection drug users (IDUs) in a population-based setting where HIV/AIDS care is delivered free of charge. METHODS: We evaluated previously untreated HIV-1 infected men and women who initiated HAART between Aug. 1, 1996, and July 31, 2000, and who were followed until Mar. 31, 2002, in a province-wide HIV treatment program. We used Kaplan-Meier methods and Cox proportional hazards regression in our evaluation of time to suppression (i.e., less than 500 copies/mL) and rebound (i.e., 500 copies/mL or more) of plasma HIV-1 RNA, with patients stratified according to whether or not they had a history of injection drug use. RESULTS: Overall, 1422 patients initiated HAART during the study period, of whom 359 (25.2%) were IDUs. In Kaplan-Meier analyses, the cumulative suppression rate at 12 months after initiation of HAART was 70.8% for non-IDUs and 51.4% for IDUs (p < 0.001) (these values include people who achieved suppression before 12 months but who might not have been followed for the full 12-month period). Among patients who achieved suppression of plasma HIV-1 RNA, the cumulative rebound rate at 12 months after initial suppression was 23.8% for non-IDUs and 34.7% for IDUs (p < 0.001). However, after adjustment for adherence and other covariates, the rates of HIV-1 RNA suppression (adjusted relative hazard 0.9, 95% confidence interval [CI] 0.7-1.0) and HIV-1 RNA rebound (adjusted relative hazard 1.3, 95% CI 1.0-1.6) were similar between non-IDUs and IDUs. Differences between non-IDUs and IDUs were even less pronounced in subanalyses that considered only therapy-adherent patients (p > 0.1). INTERPRETATION: Non-IDUs and IDUs had similar rates of HIV-1 RNA suppression and rebound after the initiation of HAART, once lower levels of adherence were taken into account. Nevertheless, the lower virological response rates among IDUs suggest that, unless interventions are undertaken to improve adherence, these patients may experience elevated rates of disease progression and use of medical services in our setting.

Adult↗
PubMed2003

Intensive injection cocaine use as the primary risk factor in the Vancouver HIV-1 epidemic.

OBJECTIVES: The explosive and ongoing injecting drug use-related HIV-1 epidemic in Vancouver continues to receive international attention. This study was conducted to determine how patterns of cocaine use influence the risk of HIV infection. METHODS: The Vancouver Injection Drug Users Study is an open prospective cohort of injecting drug users that began in May 1996. At enrollment and at semi-annual follow-up visits an interviewer administers a detailed semi-structured questionnaire. Cox proportional hazards models were used to determine behavioral and drug use patterns reported in the 6 months prior to HIV seroconversion. RESULTS: One-hundred and nine incident HIV infections have been observed during a mean follow-up of 31 months, from 940 HIV-seronegative participants. During the 6 months prior to seroconversion, predictors of HIV infection were injecting cocaine use [adjusted hazards ratio (AHR), 3.72], incarceration (AHR, 2.74), unstable housing (AHR, 2.36), methadone maintenance treatment (AHR, 1.98), and Aboriginal ethnicity (AHR, 1.78). Injecting cocaine use was predictive of HIV infection in a dose-dependent fashion. Compared with infrequent cocaine users, participants who averaged more than three injections per day were seven times more likely to contract HIV. In addition, the time to HIV infection was accelerated among regular cocaine injectors independent of concurrent heroin use. CONCLUSIONS: Injecting cocaine use was a strong, dose-dependent predictor of HIV seroconversion in this poly-drug using population. Injection cocaine users remain particularly vulnerable to HIV infection and treatment options for cocaine dependency remain woefully inadequate.

Adult↗
PubMed2003

Impact of supply-side policies for control of illicit drugs in the face of the AIDS and overdose epidemics: investigation of a massive heroin seizure.

BACKGROUND: More than 93% of the nearly $500 million spent annually on Canada's drug strategy goes toward efforts to reduce the illicit drug supply. However, little is known about the effectiveness of this strategy. On Sept. 2, 2000, Canadian police seized approximately 100 kg of heroin in one of the nation's largest-ever seizures of this drug. An ongoing prospective cohort study of injection drug users afforded an opportunity to evaluate the impact of this seizure. METHODS: The Vancouver Injection Drug User Study is a prospective cohort study of injection drug users that began in 1996. The present study relied primarily on data acquired from participants who were seen during the 30-day periods immediately before and after the seizure. We compared drug use and behavioural characteristics, heroin and cocaine prices, and participants' reports of whether law enforcement had affected their source of drugs or the types of drugs available on the street, as well as overdoses, in these 2 periods. RESULTS: The 138 participants seen before the seizure were similar to the 123 participants seen after the seizure with respect to age, sex, ethnic background, education, HIV serostatus, neighbourhood residence, instability of housing, employment status, use of methadone maintenance therapy and all other measured potential confounders (all p > 0.10). We found no difference in the extent to which participants in the 2 groups reported daily use of heroin, frequency of nonfatal overdoses, or whether law enforcement had affected their source of drugs or the types of drugs available on the street (all p > 0.10). Although we detected no difference in the price of cocaine, the median reported price of heroin went down after the seizure (p = 0.034), which suggests that other shipments compensated for the seizure. External evaluations of deaths from overdoses and heroin purity indicated that the seizure had no impact, nor was any impact seen when the periods of analysis were extended. INTERPRETATION: The massive heroin seizure appeared to have no measurable public health benefit. Closer scrutiny of enforcement efforts is warranted to ensure that resources are delivered to the most efficient and cost-effective public health programs.

Acquired Immunodeficiency Syndrome↗
PubMed2003

Risk factors for elevated HIV incidence among Aboriginal injection drug users in Vancouver.

BACKGROUND: Because of established links between entrenched poverty and risk of HIV infection, there have long been warnings that HIV/AIDS will disproportionately affect Aboriginal people in Canada. We compared HIV incidence rates among Aboriginal and non-Aboriginal injection drug users (IDUs) in Vancouver and studied factors associated with HIV seroconversion among Aboriginal participants. METHODS: This analysis was based on 941 participants (230 Aboriginal people) recruited between May 1996 and December 2000 who were seronegative at enrollment and had completed at least one follow-up visit. Incidence rates were calculated using the Kaplan-Meier method. The Cox proportional hazards regression model was used to identify independent predictors of time to HIV seroconversion among female and male Aboriginal IDUs. RESULTS: As of May 31, 2001, seroconversion had occurred in 112 (11.9%) of the participants, yielding a cumulative incidence of HIV infection at 42 months of 12.7% (95% confidence interval [CI] 10.3%-15.1%). The cumulative incidence at 42 months was significantly higher among the Aboriginal participants than among the non-Aboriginal participants (21.1% v. 10.7%, p < 0.001). This elevation in risk was present in both female and male Aboriginal IDUs. Among the female Aboriginal IDUs, frequent speedball (combined cocaine and heroin) injection (adjusted relative risk [RR] 3.1; 95% CI 1.4-7.1) and going on binges of injection drug use (adjusted RR 2.3; 95% CI 1.0-5.2) were found to be independent predictors of HIV seroconversion. Among the male Aboriginal IDUs, the independent predictors of seroconversion were frequent speedball injection (adjusted RR 2.9; 95% CI 1.0-8.5) and frequent cocaine injection (adjusted RR 2.5; 95% CI 1.0-6.5). INTERPRETATION: In Vancouver, Aboriginal IDUs are becoming HIV positive at twice the rate of non-Aboriginal IDUs. Our findings emphasize the urgent need for an appropriate and effective public health strategy--planned and implemented in partnership with Aboriginal AIDS service organizations and the Aboriginal community--to reduce the harms of injection drug use in this population.

Adolescent↗
PubMed2003

The potential public health and community impacts of safer injecting facilities: evidence from a cohort of injection drug users.

BACKGROUND: Although medically supervised safer injecting facilities (SIFs) remain untested in North America, their implementation is currently being debated. Reluctance of health policy makers to initiate a pilot study of SIFs may in part be hindered by outstanding questions regarding the potential community and public health impact of the intervention. Specifically, it is presently unknown if those at greatest risk of overdose and HIV transmission or those responsible for community impact of injection drug use will be willing to attend. METHODS: The current study was conducted to evaluate the proportion of injection drug users (IDU) willing to attend medically supervised SIFs, if they were available, among participants enrolled in the Vancouver Injection Drug User Study (VIDUS). The authors also evaluated factors associated with willingness to use a SIF using univariate and logistic regression analyses. Participants who were followed from June 2001 to June 2002 were eligible for the present analyses. RESULTS: Overall, 587 active IDU responded to a questionnaire during the study period. Among respondents, 215 (36.6%) expressed willingness to attend a SIF. Variables that were independently associated with willingness to attend a SIF in multivariate analyses included having difficulty accessing sterile syringes (adjusted odds ratio [AOR] = 2.07), requiring help injecting (AOR = 1.52), frequently injecting heroin (AOR = 1.81), sex trade work (AOR = 2.02), and injecting in public spaces (AOR = 2.00). CONCLUSIONS: Several variables that have recently been associated with overdose, syringe sharing, HIV and HCV incidence, and community impact of illicit drug use in this setting were associated with willingness to attend medically supervised SIFs. Although the impact of SIFs in North America can only be quantified by scientific evaluation, these data indicate a high potential for immediate community and public health benefits if SIFs were presently available.

Adult↗
PubMed2003

An open-label randomized clinical trial of novel therapeutic strategies for HIV-infected patients in whom antiretroviral therapy has failed: rationale and design of the OPTIMA Trial.

OPTIMA (OPTions In Management with Antiretrovirals) is a clinical trial with a factorial randomization to evaluate the hypotheses that mega-antiretroviral therapy (ART) consisting of five or more anti-HIV drugs compared to standard-ART consisting of four or fewer anti-HIV drugs and a 3-month antiretroviral drug-free period (ARDFP) compared to no ARDFP will delay the occurrence of new or recurrent acquired immunodeficiency syndrome events or death, and prove to be more cost-effective in treating human immunodeficiency virus-infected individuals previously exposed to ART drugs from the current three main classes. The aim is to randomize 1,700 participants to four treatment strategy arms: (1) ARDFP+standard-ART; (2) ARDFP+mega-ART; (3) no ARDFP+standard-ART; (4) no ARDFP+mega-ART. The planned study duration is 3.5 years with 2.5 years of intake and a minimum 1 year of follow-up. The OPTIMA Trial was initiated in June 2001 at 30 U.S. Department of Veterans' Affairs hospitals, 22 hospitals in Canada, and 25 hospitals in the United Kingdom. This is the first large-scale, multicenter, randomized controlled trial to compare the relative efficacy of these different therapeutic strategies. We discuss the rationale behind the OPTIMA Trial design as well as the issues arising from the conduct of a trial that involves three national clinical trial agencies.

Adult↗
PubMed2003

Sexual violence among a cohort of injection drug users.

The objective of this study was to determine the prevalence of, and factors associated with, sexual violence in childhood, adolescence and adulthood, among injection drug using men and women. The Vancouver Injection Drug User Study is a prospective cohort of injection drug users (IDU) begun in 1996. The analysis included all individuals who completed the baseline questionnaire who responded to a question about sexual assault. Multivariate modeling was used to determine and to what extent a history of sexual violence at different ages is predictive of HIV risk and other health risk behaviors. HIV prevalence was calculated as the total current number of HIV-positive individuals in the cohort. Of the 1437 eligible individuals, 36% reported a lifetime history of sexual violence; 68% of women, and 19% of men (p<0.001). After adjusting for fixed sociodemographics, these individuals were more likely to have ever been in the sex trade, to knowingly share needles/rigs with HIV-positive people, to have attempted suicide, to have ever accidentally overdosed, to binge on alcohol, and to have been diagnosed with a mental disorder/disability. The prevalence of child sexual abuse in this cohort is 21%; 33% for women, and 13% for men. The data show a dose-response relationship between age at first sexual violence and most risk behaviors examined. These relationships are further mediated by gender. The prevalence of HIV among individuals who ever experienced sexual violence was 25%, compared to 19% among those who never experienced sexual violence (p=0.006). Sexual violence, and especially child sexual abuse, is highly prevalent among this cohort, particularly among women. Child sexual abuse has worse consequences for both genders than sexual violence later in life. Nevertheless, women and men are affected differently by sexual violence at different ages, and this has significant implications for health promotion programs, and specifically HIV prevention.

Adolescent↗
PubMed2003

Predictors of early hospital readmission in HIV-infected patients with pneumonia.

OBJECTIVE: Although hospitalization patterns have been studied, little is known about hospital readmission among HIV-infected patients in the era of highly active antiretroviral therapy. We explored the risk factors for early readmission to a tertiary care inner-city hospital among HIV-infected patients with pneumonia in Vancouver, Canada. DESIGN: Case-control study. SETTING: Tertiary care, university-affiliated, inner-city hospital. PARTICIPANTS: All HIV-infected patients who were hospitalized with Pneumocystis carinii pneumonia (PCP) or bacterial pneumonia (BP) between January 1997 and December 2000. Case patients included those who had early readmissions, defined as being readmitted within 2 weeks of discharge (N = 131). Control patients were randomly selected HIV-infected patients admitted during the study period who were not readmitted within 2 weeks of discharge (N = 131), matched to the cases by proportion of PCP to BP. MEASUREMENTS: Sociodemographic, HIV risk category, and clinical data were compared using chi2 test for categorical variables, and the Wilcoxon rank-sum test was used for continuous variables. Multivariable logistic regression was performed to determine the factors independently associated with early readmission. We also reviewed the medical records of 132 patients admitted to the HIV/AIDS ward during the study period and collected more detailed clinical data for a subanalysis. MAIN RESULTS: Patients were at significantly increased odds of early readmission if they left the hospital against medical advice (AMA) (adjusted odds ratio [OR], 4.26; 95% confidence interval [95% CI], 2.13 to 8.55), lived in the poorest urban neighborhood (OR, 2.03; 95% CI, 1.09 to 3.77), were hospitalized in summer season (May though October, OR, 2.36; 95% CI, 1.36 to 4.10), or had been admitted in the preceding 6 months (OR, 2.55; 95% CI, 1.46 to 4.47). Gender, age, history of AIDS-defining illness, and injection drug use status were not significantly associated with early readmission. CONCLUSIONS: Predictors of early readmission of HIV-infected patients with pneumonia included: leaving hospital AMA, living in the poorest urban neighborhood, being hospitalized in the preceding 6 months and during the summer months. Interventions involving social work may address some of the underlying reasons why these patients leave hospital AMA and should be further studied.

AIDS-Related Opportunistic Infections↗
PubMed2003

An external evaluation of a peer-run "unsanctioned" syringe exchange program.

In Vancouver, British Columbia, Canada, difficulty accessing syringes at night has been shown to be strongly associated with human immunodeficiency virus (HIV) risk behavior among the city's injection drug users (IDUs). On September 1, 2001, the Vancouver Area Network of Drug Users (VANDU) initiated an unsanctioned all-night needle-exchange program on a street corner in the heart of the neighborhood where many of the city's IDUs are concentrated. An external evaluation of the population reached by the VANDU exchange was performed through the Vancouver Injection Drug User's Study, a prospective cohort study of IDUs begun in 1996. Persons accessing syringes through the exchange were compared to those active injectors who acquired their syringes from other sources, including the city's fixed site exchange, which closes at 8:00 PM. Overall, 587 active IDUs were seen during the period September 2001 to June 2002; of these individuals, 165 (28.1%) reported using the VANDU exchange. In multivariate analyses, participants who used the VANDU table were more likely to frequently inject cocaine (adjusted odds ratio [AOR]=1.56; 95% confidence interval [CI]=1.00-2.44), inject in public (AOR=2.71; 95% CI=1.62-4.53), and require help injecting (OR=2.13; 95% CI=1.33-3.42). Interestingly, use of the table was also independently associated with safer syringe disposal (AOR=2.69; 95% CI=1.38-5.21). Results indicate that the unsanctioned exchange appears to have reached those IDUs at highest risk of HIV infection. Although the cross-sectional nature of the study design warrants caution, we also found that use of the nighttime exchange was strongly associated with higher rates of safe syringe disposal. The data suggest that drug user organizations can play a major role in reducing harm among their peers by reaching the highest risk drug users with harm reduction services. The findings also suggest that other forms of syringe-exchange programs should consider the benefits of offering fixed site nighttime service.

Adult↗