Expanded syringe exchange programs and reduced HIV infection among new injection drug users in Tallinn, Estonia

<p>Abstract</p> <p>Background</p> <p>Estonia has experienced an HIV epidemic among intravenous drug users (IDUs) with the highest per capita HIV prevalence in Eastern Europe. We assessed the effects of expanded syringe exchange programs (SEP) in the capital city, Tallinn, which has an estimated 10,000 IDUs.</p> <p>Methods</p> <p>SEP implementation was monitored with data from the Estonian National Institute for Health Development. Respondent driven sampling (RDS) interview surveys with HIV testing were conducted in Tallinn in 2005, 2007 and 2009 (involving 350, 350 and 327 IDUs respectively). HIV incidence among new injectors (those injecting for < = 3 years) was estimated by assuming (1) new injectors were HIV seronegative when they began injecting, and (2) HIV infection occurred at the midpoint between first injection and time of interview.</p> <p>Results</p> <p>SEP increased from 230,000 syringes exchanged in 2005 to 440,000 in 2007 and 770,000 in 2009. In all three surveys, IDUs were predominantly male (80%), ethnic Russians (>80%), and young adults (mean ages 24 to 27 years). The proportion of new injectors decreased significantly over the years (from 21% in 2005 to 12% in 2009, p = 0.005). HIV prevalence among all respondents stabilized at slightly over 50% (54% in 2005, 55% in 2007, 51% in 2009), and decreased among new injectors (34% in 2005, 16% in 2009, p = 0.046). Estimated HIV incidence among new injectors decreased significantly from 18/100 person-years in 2005 and 21/100 person-years in 2007 to 9/100 person-years in 2009 (p = 0.026).</p> <p>Conclusions</p> <p>In Estonia, a transitional country, a decrease in the HIV prevalence among new injectors and in the numbers of people initiating injection drug use coincided with implementation of large-scale SEPs. Further reductions in HIV transmission among IDUs are still required. Provision of 70 or more syringes per IDU per year may be needed before significant reductions in HIV incidence occur.</p

Estimating adjusted prevalence ratio in clustered cross-sectional epidemiological data

BACKGROUND: Many epidemiologic studies report the odds ratio as a measure of association for cross-sectional studies with common outcomes. In such cases, the prevalence ratios may not be inferred from the estimated odds ratios. This paper overviews the most commonly used procedures to obtain adjusted prevalence ratios and extends the discussion to the analysis of clustered cross-sectional studies. METHODS: Prevalence ratios(PR) were estimated using logistic models with random effects. Their 95% confidence intervals were obtained using delta method and clustered bootstrap. The performance of these approaches was evaluated through simulation studies. Using data from two studies with health-related outcomes in children, we discuss the interpretation of the measures of association and their implications. RESULTS: The results from data analysis highlighted major differences between estimated OR and PR. Results from simulation studies indicate an improved performance of delta method compared to bootstrap when there are small number of clusters. CONCLUSION: We recommend the use of logistic model with random effects for analysis of clustered data. The choice of method to estimate confidence intervals for PR (delta or bootstrap method) should be based on study design

Parental Immigration Status is Associated with Children’s Health Care Utilization: Findings from the 2003 New Immigrant Survey of US Legal Permanent Residents

Our objective was to examine the association between parental immigration status and child health and health care utilization. Using data from a national sample of immigrant adults who had recently become legal permanent residents (LPR), children (n = 2,170) were categorized according to their parents’ immigration status prior to LPR: legalized, mixed-status, refugee, temporary resident, or undocumented. Logistic regression with generalized estimating equations was used to compare child health and health care utilization by parental immigration status over the prior 12 months. Nearly all children in the sample were reported to be in good to excellent health. Children whose parents had been undocumented were least likely to have had an illness that was reported to have required medical attention (5.4 %). Children whose parents had been either undocumented or temporary residents were most likely to have a delayed preventive annual exam (18.2 and 18.7 %, respectively). Delayed dental care was most common among children whose parents had come to the US as refugees (29.1 %). Differences in the preventive annual exam remained significant after adjusting for socioeconomic characteristics. Parental immigration status before LPR was not associated with large differences in reported child health status. Parental immigration status before LPR was associated with the use of preventive annual exams and dental services. However, no group of children was consistently disadvantaged with respect to all measures