Reporting of observational studies is often inadequate, hampering the assessment of their strengths and weaknesses and, consequently, the generalization of study results. The initiative named Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) developed a checklist of 22 items, the STROBE Statement, with recommendations about what should be included in a more accurate and complete description of observational studies. Between June and December 2008, a group of Brazilian researchers was dedicated to the translation and adaptation of the STROBE Statement into Portuguese. The present study aimed to show the translation into Portuguese, introduce the discussion on the context of use, the potential and limitations of the STROBE initiative. Clinical trials and observational studies in the context of modern biomedical researchRandomized clinical trials have been described as the gold standard for biomedical research as they show high internal validity and, consequently, greater accuracy in the effi cacy and effectiveness evaluation of several therapeutic and preventive health practices. 4 However, public health studies have frequently dealt with problems where this study design is not adequate and/or ethical, or, yet, for which the translation of randomized controlled trial fi ndings into concrete intervention and/or treatment conditions faces great diffi culties due to the lack of external validity of fi ndings obtained in a clinical trial context. According to Victora et al,26 randomized clinical trials frequently represent an inadequate choice to assess the performance and impact of large scale interventions, especially in contexts of heterogeneity, whether they are social, economic and/or geographic in nature. In addition, there are operational aspects that can hinder or even preclude the implementation of clinical trials: individuals may not want to be randomized for a given intervention group, randomized selection may not be possible or ethically acceptable in the research context, or, yet, only participants with certain characteristics might accept to be selected. 31 In view of the impossibility or inadequacy of implementation of randomized clinical trials, whether due to ethical or operational questions, observational studies appear as a more feasible solution and, in cohort studies, are relevant alternatives to evaluate the impact of interventions throughout time. 22Observational studies are more adequate to evaluate rare or late side effects associated with certain treatments and they often provide a more accurate indication of what can be achieved in routine clinical practice, once they take The adverse effects of non-steroidal anti-infl ammatory drugs on cardiovascular morbi-mortality has been documented in studies with large sample sizes and longterm follow-up. Until then, these side effects had been imperceptible in the context of clinical trials and even of pharmacovigilance, involving a small number of cases and/or having a relatively short follow-up period. 10Previous...

While lower than other populations-especially among users of stimulants, incarcerated DU and patients with psychiatric comorbidities-adherence to HAART among HIV-positive DU can be achieved. Better adherence was identified among those engaged in comprehensive services providing HIV and addiction treatment with psychosocial support.

We conducted a meta-analysis of studies assessing adherence to highly active antiretroviral therapy (HAART) and a qualitative systematic review of factors associated with better HAART outcomes among HIV+ drug users (DU). Thirty-eight studies were considered, which analyzed 14,960 patients (11,394 HIV+ DU, 76.2%). Overall adherence (pooled percent of DU classified as adherent in each study) was 0.60 (95% CI: 0.52-0.68), similar to levels identified by studies conducted with HIV+ patients who are not drug users. Time frame used to measure adherence was an independent predictor of inter-study heterogeneity. The systematic review identified better HAART outcomes among former DU, those with less severe psychiatric conditions, those receiving opioid substitution therapy and/or psychosocial support. Patients initiating HAART with lower viral load and higher CD4 counts, and those without co-infections also had better treatment outcomes. Our findings suggest that HIV+ DU tend to be inappropriately assumed to be less adherent and unlikely to achieve desirable treatment outcomes, when compared to their non-DU cohort.