Ariel Bardach

Publications (49) View all

• Source

  Available from: Demián Glujovsky

  Article: Characteristics of randomized trials published in latin america and the Caribbean according to funding source.

  Ludovic Reveiz, Stephanie Sangalang, Demian Glujovsky, Carlos E Pinzon, Claudia Asenjo Lobos, Marcela Cortes, Martin Cañón, Ariel Bardach, Xavier Bonfill
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  ABSTRACT: Few studies have assessed the nature and quality of randomized controlled trials (RCTs) in Latin America and the Caribbean (LAC). The aims of this systematic review are to evaluate the characteristics (including the risk of bias assessment) of RCT conducted in LAC according to funding source. A review of RCTs published in 2010 in which the author's affiliation was from LAC was performed in PubMed and LILACS. Two reviewers independently extracted data and assessed the risk of bias. The primary outcomes were risk of bias assessment and funding source. A total of 1,695 references were found in PubMed and LILACS databases, of which 526 were RCTs (N = 73.513 participants). English was the dominant publication language (93%) and most of the RCTs were published in non-LAC journals (84.2%). Only five of the 19 identified countries accounted for nearly 95% of all RCTs conducted in the region (Brazil 70.9%, Mexico 10.1%, Argentina 5.9%, Colombia 3.8%, and Chile 3.4%). Few RCTs covered priority areas related with Millennium Development Goals like maternal health (6.7%) or high priority infectious diseases (3.8%). Regarding children, 3.6% and 0.4% RCT evaluated nutrition and diarrhea interventions respectively but none pneumonia. As a comparison, aesthetic and sport related interventions account for 4.6% of all trials. A random sample of RCTs (n = 358) was assessed for funding source: exclusively public (33.8%); private (e.g. pharmaceutical company) (15.3%); other (e.g. mixed, NGO) (15.1%); no funding (35.8%). Overall assessments for risk of bias showed no statistically significant differences between RCTs and type of funding source. Statistically significant differences favoring private and others type of funding was found when assessing trial registration and conflict of interest reporting. Findings of this study could be used to provide more direction for future research to facilitate innovation, improve health outcomes or address priority health problems.
  PLoS ONE 01/2013; 8(2):e56410. · 4.09 Impact Factor
• Article: Burden of influenza in Latin America and the Caribbean: a systematic review and meta-analysis.

  Vilma Savy, Agustín Ciapponi, Ariel Bardach, Demián Glujovsky, Patricia Aruj, Agustina Mazzoni, Luz Gibbons, Eduardo Ortega-Barría, Rómulo E Colindres
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  ABSTRACT: Please cite this paper as: Savy et al. (2012) Burden of influenza in Latin America and the Caribbean: a systematic review and meta-analysis. Influenza and Other Respiratory Viruses DOI: 10.1111/irv.12036. Objective  Influenza causes severe morbidity and mortality. This systematic review aimed to assess the incidence, etiology, and resource usage for influenza in Latin America and the Caribbean. Design  Meta-analytic systematic review. Arcsine transformations and DerSimonian Laird random effects model were used for meta-analyses. Setting  A literature search from 1980 to 2008 in MEDLINE, Cochrane Library, EMBASE, LILACS, Ministries of Health, PAHO, proceedings, reference lists, and consulting experts. Sample  We identified 1092 references, of which 31 were finally included, in addition to influenza surveillance reports. We also used information from the 10 reports from the collaborative group for epidemiological surveillance of influenza and other respiratory virus (GROG), and information retrieved from the WHO global flu database FLUNET. Main outcome measures  Incidence, percentage of influenza specimens out of the total received by influenza centers and resource-use outcomes. Results  A total of 483 130 specimens of patients with influenza were analyzed. Meta-analysis showed an annual rate of 36 080 (95%CI 28 550 43 610) influenza-like illness per 100 000 persons-years. The percentage of influenza out of total specimens received by influenza centers ranged between 4.66% and 15.42%, with type A the most prevalent, and A subtype H3 predominating. The mean length of stay at hospital due to influenza ranged between 5.8 12.9 days, total workdays lost due to influenza-like illnesses were 17 150 days, and the mean direct cost of hospitalization was US$575 per laboratory-confirmed influenza case. Conclusions  Our data show that seasonal influenza imposes a high morbidity and economic burden to the region. However, the vaccine-uptake rate has been low in this region. Population-based cohort studies are required to improve the knowledge about incidence and resource utilization, which would inform healthcare authorities for decision making.
  Influenza and Other Respiratory Viruses 12/2012; · 4.16 Impact Factor
• Article: Incidence and Use of Resources for Chickenpox and Herpes Zoster in Latin America and the Caribbean-A Systematic Review and Meta-analysis.

  Ariel Bardach, María Luisa Cafferata, Karen Klein, Gabriela Cormick, Luz Gibbons, Silvina Ruvinsky
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  ABSTRACT: : Varicella-zoster virus causes chickenpox and herpes zoster. More than 90% of varicella cases occur in childhood. The aim of this study was to gather all relevant information on epidemiology and resource use in Latin America and the Caribbean since 2000. : Epidemiologic studies published since 2000 with at least 50 cases of varicella or herpes zoster, or at least 10 cases of congenital disease were included. Gray literature was also searched. Outcomes included incidence, admission rate, mortality and case-fatality ratio. Use of resources and both direct and indirect costs associated were extracted. : From the 495 records identified, 23 were included in the meta-analysis to report varicella-zoster virus outcomes and 3 in the herpes zoster analysis. The global pooled varicella incidence in subjects under 15 years of age was 42.9 cases per 1000 individuals per year (95% confidence interval: 26.9-58.9); children under 5 years of age were the most affected. Pooled general admission rate was 3.5 per 100,000 population (95% confidence interval: 2.9-4.1) and median hospitalization was 5-9 days. The most common varicella complications reported in studies were skin infections (3-61%), followed by respiratory infections (0-15%) and neurologic problems (1-5%). Direct costs averaged (2011/international dollar [I$]) $2040 per admission (range, I$ 298-5369) and I$70 per clinical visit (range, 11-188 I$). : Limited information was available on the outcomes studied. Improvements in the surveillance of ambulatory cases are required to obtain a better epidemiologic picture. As of 2011, only 2 countries introduced the vaccine in national immunization programs in Latin America and the Caribbean.
  The Pediatric Infectious Disease Journal 12/2012; 31(12):1263-8. · 3.58 Impact Factor
• Article: Trial registration in Latin America and the Caribbean's: study of randomized trials published in 2010.

  Ludovic Reveiz, Xavier Bonfill, Demian Glujovsky, Carlos E Pinzon, Claudia Asenjo-Lobos, Marcela Cortes, Martin Canon, Ariel Bardach, Daniel Comandé, Andrés F Cardona
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  ABSTRACT: To determine the prevalence of trial registration in randomized controlled trials (RCTs) published in 2010 (PUBMED/LILACS) from Latin America and the Caribbean's (LAC) and to compare methodological characteristics between registered and nonregistered RCTs. A search for detecting RCTs in which at least the first/contact author had a LAC's affiliation was made. We determined if RCTs were registered in the International Clinical Trial Registry Platform (ICTRP). Data were independently extracted by two authors. The risk of bias (RoB) was assessed in all registered RCTs (n=89) and in a sample of nonregistered RCTs (n=237). The search identified 1,695 references; 526 RCTs from 19 countries were included. 16.9% (89/526) of RCTs were registered in the ICTRP; however, only 21 (4.0%) were prospectively registered. A significant difference was found in the overall assessment of the RoB between registered and nonregistered RCTs. Overall, registered RCTs were multinational, had larger sample size and longer follow-up, and reported more frequently information on funding, conflict of interests, and ethic issues. No significant differences were found when analyzing prospectively registered RCTs. This study shows that trial registration rates are still low in LAC and the quality of reporting needs to be improved.
  Journal of clinical epidemiology 01/2012; 65(5):482-7. · 2.96 Impact Factor
• Article: Cleavage stage versus blastocyst stage embryo transfer in assisted reproductive technology.

  Demián Glujovsky, Debbie Blake, Cindy Farquhar, Ariel Bardach
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  ABSTRACT: Advances in cell culture media have led to a shift in in vitro fertilization (IVF) practice from early cleavage embryo transfer to blastocyst stage transfer. The rationale for blastocyst culture is to improve both uterine and embryonic synchronicity and enable self selection of viable embryos thus resulting in higher implantation rates. To determine if blastocyst stage (Day 5 to 6) embryo transfers (ETs) improve live birth rate and other associated outcomes compared with cleavage stage (Day 2 to 3) ETs. Cochrane Menstrual Disorders and Subfertility Group Specialised Register of controlled trials, Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), MEDLINE, EMBASE and Bio extracts. The last search date was 21 February 2012. Trials were included if they were randomised and compared the effectiveness of early cleavage versus blastocyst stage transfers. Of the 50 trials that were identified, 23 randomised controlled trials (RCTs) met the inclusion criteria and were reviewed (five new studies were added in this update). The primary outcome was rate of live birth. Secondary outcomes were rates per couple of clinical pregnancy, cumulative clinical pregnancy, multiple pregnancy, high order pregnancy, miscarriage, failure to transfer embryos and cryopreservation. Quality assessment, data extraction and meta-analysis were performed following Cochrane guidelines. Twelve RCTs reported live birth rates and there was evidence of a significant difference in live birth rate per couple favouring blastocyst culture (1510 women, Peto OR 1.40, 95% CI 1.13 to 1.74) (Day 2 to 3: 31%; Day 5 to 6: 38.8%, I(2) = 40%). This means that for a typical rate of 31% in clinics that use early cleavage stage cycles, the rate of live births would increase to 32% to 42% if clinics used blastocyst transfer.There was no difference in clinical pregnancy rate between early cleavage and blastocyst transfer in the 23 RCTs (Peto OR 1.14, 95% CI 0.99 to 1.32) (Day 2 to 3: 38.6%; Day 5 to 6: 41.6%) and no difference in miscarriage rate (13 RCTs, Peto OR 1.18, 95% CI 0.86 to 1.60). The four RCTs that reported cumulative pregnancy rates (266 women, Peto OR 1.58, 95% CI 1.11 to 2.25) (Day 2 to 3: 56.8%; Day 5 to 6: 46.3%) significantly favoured early cleavage. Embryo freezing rates (11 RCTs, 1729 women, Peto OR 2.88, 95% CI 2.35 to 3.51) and failure to transfer embryos (16 RCTs, 2459 women, OR 0.35, 95% CI 0.24 to 0.51) (Day 2 to 3: 3.4%; Day 5 to 6: 8.9%) favoured cleavage stage transfer. This review provides evidence that there is a small significant difference in live birth rates in favour of blastocyst transfer (Day 5 to 6) compared to cleavage stage transfer (Day 2 to 3). However, cumulative clinical pregnancy rates from cleavage stage (derived from fresh and thaw cycles) resulted in higher clinical pregnancy rates than from blastocyst cycles. The most likely explanation for this is the higher rates of frozen embryos and lower failure to transfer rates per couple obtained from cleavage stage protocols. Future RCTs should report miscarriage, live birth and cumulative live birth rates to enable ART consumers and service providers to make well informed decisions on the best treatment option available.
  Cochrane database of systematic reviews (Online) 01/2012; 7:CD002118. · 5.72 Impact Factor