Outcomes in patients waiting for antiretroviral treatment in the Free State Province, South Africa: prospective linkage study.

Objective: In South Africa, many HIV-infected patients experience delays in accessing antiretroviral therapy (ART). We examined pretreatment mortality and access to treatment in patients waiting for ART.

Design: Cohort of HIV-infected patients assessed for ART eligibility at 36 facilities participating in the Comprehensive HIV and AIDS Management (CHAM) program in the Free State Province.

A sequential Cox approach for estimating the causal effect of treatment in the presence of time-dependent confounding applied to data from the Swiss HIV Cohort Study.

When estimating the effect of treatment on HIV using data from observational studies, standard methods may produce biased estimates due to the presence of time-dependent confounders. Such confounding can be present when a covariate, affected by past exposure, is both a predictor of the future exposure and the outcome. One example is the CD4 cell count, being a marker for disease progression for HIV patients, but also a marker for treatment initiation and influenced by treatment.

Prognosis of patients with HIV-1 infection starting antiretroviral therapy in sub-Saharan Africa: a collaborative analysis of scale-up programmes.

Background: Prognostic models have been developed for patients infected with HIV-1 who start combination antiretroviral therapy (ART) in high-income countries, but not for patients in sub-Saharan Africa. We developed two prognostic models to estimate the probability of death in patients starting ART in sub-Saharan Africa.

Methods: We analysed data for adult patients who started ART in four scale-up programmes in Côte d'Ivoire, South Africa, and Malawi from 2004 to 2007.

Strategies for multiple imputation in longitudinal studies.

Multiple imputation is increasingly recommended in epidemiology to adjust for the bias and loss of information that may occur in analyses restricted to study participants with complete data ("complete-case analyses"). However, little guidance is available on applying the method, including which variables to include in the imputation model and the number of imputations needed. Here, the authors used multiple imputation to analyze the prevalence of wheeze among 81-month-old children in the Avon Longitudinal Study of Parents and Children (Avon, United Kingdom; 1991-1999) and the association of wheeze with gender, maternal asthma, and maternal smoking.

Development of a combined database for meta-epidemiological research.

Collections of meta-analyses assembled in meta-epidemiological studies are used to study associations of trial characteristics with intervention effect estimates. However, methods and findings are not consistent across studies. To combine data from 10 meta-epidemiological studies into a single database, and derive a harmonized dataset without overlap between meta-analyses.

Systematic review: accuracy of anti-citrullinated Peptide antibodies for diagnosing rheumatoid arthritis.

Background: Early recognition and treatment of rheumatoid arthritis is important to prevent irreversible joint damage. Anti-citrullinated peptide antibodies (ACPA) have been suggested for early diagnosis.

Purpose: To compare the accuracy of ACPA and rheumatoid factor in diagnosing rheumatoid arthritis in patients with early symptoms of the disease.

The association between BMI and mortality using offspring BMI as an indicator of own BMI: large intergenerational mortality study.

Objectives: To obtain valid estimates of the association between body mass index (BMI) and mortality by using offspring BMI as an instrumental variable for own BMI.

Design: Cohort study based on record linkage, with 50 years of follow-up for mortality. Associations of offspring BMI with all cause and cause specific maternal and paternal mortality were estimated as hazard ratios per standard deviation of offspring BMI.

Colour vision testing for diabetic retinopathy: a systematic review of diagnostic accuracy and economic evaluation.

Objective: To determine the diagnostic performance and cost-effectiveness of colour vision testing (CVT) to identify and monitor the progression of diabetic retinopathy (DR).

Data Sources: Major electronic databases including MEDLINE, EMBASE, Cumulative Index to Nursing and Allied Health Literature, and Cochrane Database of Systematic Reviews were searched from inception to September 2008.

Review Methods: A systematic review of the evidence was carried out according to standard methods.

Prognosis of patients treated with cART from 36 months after initiation, according to current and previous CD4 cell count and plasma HIV-1 RNA measurements.

Objectives: CD4 cell count and plasma viral load are well known predictors of AIDS and mortality in HIV-1-infected patients treated with combination antiretroviral therapy (cART). This study investigated, in patients treated for at least 3 years, the respective prognostic importance of values measured at cART initiation, and 6 and 36 months later, for AIDS and death.

Methods: Patients from 15 HIV cohorts included in the ART Cohort Collaboration, aged at least 16 years, antiretroviral-naive when they started cART and followed for at least 36 months after start of cART were eligible.

The effect of combined antiretroviral therapy on the overall mortality of HIV-infected individuals.

Objective: To estimate the effect of combined antiretroviral therapy (cART) on mortality among HIV-infected individuals after appropriate adjustment for time-varying confounding by indication.

Design: A collaboration of 12 prospective cohort studies from Europe and the United States (the HIV-CAUSAL Collaboration) that includes 62 760 HIV-infected, therapy-naive individuals followed for an average of 3.3 years.

The double jeopardy of clustered measurement and cluster randomisation.

suggest that double clustering might explain the negative results of some cluster randomised trials and describe some strategies for avoiding the problem

Effect of baseline CD4 cell counts on the clinical significance of short-term immunologic response to antiretroviral therapy in individuals with virologic suppression.

Background: Achieving virologic suppression is a clear therapeutic goal for patients receiving combination antiretroviral therapy (cART). However, the effects of immunologic responses, whether measured as CD4 count changes from baseline or CD4 counts at follow-up, in patients with virologic suppression, have not been clearly established.

Methods: Treatment-naive individuals aged > or =16 years, who initiated cART between 1998 and 2005 in participating cohorts of the ART Cohort Collaboration and achieved viral load < or =400 copies per milliliter 6 months after cART initiation, were included.

A review of reporting of participant recruitment and retention in RCTs in six major journals.

Background: Poor recruitment and retention of participants in randomised controlled trials (RCTs) is problematic but common. Clear and detailed reporting of participant flow is essential to assess the generalisability and comparability of RCTs. Despite improved reporting since the implementation of the CONSORT statement, important problems remain.

Multiple imputation for missing data in epidemiological and clinical research: potential and pitfalls.

Most studies have some missing data. describe the appropriate use and reporting of the multiple imputation approach to dealing with them

Timing of initiation of antiretroviral therapy in AIDS-free HIV-1-infected patients: a collaborative analysis of 18 HIV cohort studies.

Background: The CD4 cell count at which combination antiretroviral therapy should be started is a central, unresolved issue in the care of HIV-1-infected patients. In the absence of randomised trials, we examined this question in prospective cohort studies.

Methods: We analysed data from 18 cohort studies of patients with HIV.

An empirical comparison of methods for meta-analysis of diagnostic accuracy showed hierarchical models are necessary.

Objective: Meta-analysis of studies of the accuracy of diagnostic tests currently uses a variety of methods. Statistically rigorous hierarchical models require expertise and sophisticated software. We assessed whether any of the simpler methods can in practice give adequately accurate and reliable results.

Prognostic importance of anaemia in HIV type-1-infected patients starting antiretroviral therapy: collaborative analysis of prospective cohort studies.

Background: In HIV type-1-infected patients starting highly active antiretroviral therapy (HAART), the prognostic value of haemoglobin when starting HAART, and of changes in haemoglobin levels, are not well defined.

Methods: We combined data from 10 prospective studies of 12,100 previously untreated individuals (25% women). A total of 4,222 patients (35%) were anaemic: 131 patients (1.