Alberto Narváez

Ottawa Hospital Research Institute, Ottawa, Ontario, Canada

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Publications (7)99.1 Total impact

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    ABSTRACT: BACKGROUND: We report the main findings of the WHO Multicountry Survey on Maternal and Newborn Health (WHOMCS), which aimed to assess the burden of complications related to pregnancy, the coverage of key maternal health interventions, and use of the maternal severity index (MSI) in a global network of health facilities. METHODS: In our cross-sectional study, we included women attending health facilities in Africa, Asia, Latin America, and the Middle East that dealt with at least 1000 childbirths per year and had the capacity to provide caesarean section. We obtained data from analysis of hospital records for all women giving birth and all women who had a severe maternal outcome (SMO; ie, maternal death or maternal near miss). We regarded coverage of key maternal health interventions as the proportion of the target population who received an indicated intervention (eg, the proportion of women with eclampsia who received magnesium sulphate). We used areas under the receiver operator characteristic curves (AUROC) with 95% CI to externally validate a previously reported MSI as an indicator of severity. We assessed the overall performance of care (ie, the ability to produce a positive effect on health outcomes) through standardised mortality ratios. RESULTS: From May 1, 2010, to Dec 31, 2011, we included 314 623 women attending 357 health facilities in 29 countries (2538 had a maternal near miss and 486 maternal deaths occurred). The mean period of data collection in each health facility was 89 days (SD 21). 23 015 (7·3%) women had potentially life-threatening disorders and 3024 (1·0%) developed an SMO. 808 (26·7%) women with an SMO had post-partum haemorrhage and 784 (25·9%) had pre-eclampsia or eclampsia. Cardiovascular, respiratory, and coagulation dysfunctions were the most frequent organ dysfunctions in women who had an SMO. Reported mortality in countries with a high or very high maternal mortality ratio was two-to-three-times higher than that expected for the assessed severity despite a high coverage of essential interventions. The MSI had good accuracy for maternal death prediction in women with markers of organ dysfunction (AUROC 0·826 [95% CI 0·802-0·851]). INTERPRETATION: High coverage of essential interventions did not imply reduced maternal mortality in the health-care facilities we studied. If substantial reductions in maternal mortality are to be achieved, universal coverage of life-saving interventions need to be matched with comprehensive emergency care and overall improvements in the quality of maternal health care. The MSI could be used to assess the performance of health facilities providing care to women with complications related to pregnancy. FUNDING: UNDP-UNFPA-UNICEF-WHO-World Bank Special Programme of Research, Development and Research Training in Human Reproduction (HRP); WHO; USAID; Ministry of Health, Labour and Welfare of Japan; Gynuity Health Projects.
    The Lancet 05/2013; 381(9879):1747-1755. · 39.21 Impact Factor
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    ABSTRACT: Caesarean section rates continue to increase worldwide with uncertain medical consequences. Auditing and analysing caesarean section rates and other perinatal outcomes in a reliable and continuous manner is critical for understanding reasons caesarean section changes over time. We analyzed data on 97,095 women delivering in 120 facilities in 8 countries, collected as part of the 2004-2005 Global Survey on Maternal and Perinatal Health in Latin America. The objective of this analysis was to test if the "10-group" or "Robson" classification could help identify which groups of women are contributing most to the high caesarean section rates in Latin America, and if it could provide information useful for health care providers in monitoring and planning effective actions to reduce these rates. The overall rate of caesarean section was 35.4%. Women with single cephalic pregnancy at term without previous caesarean section who entered into labour spontaneously (groups 1 and 3) represented 60% of the total obstetric population. Although women with a term singleton cephalic pregnancy with a previous caesarean section (group 5) represented only 11.4% of the obstetric population, this group was the largest contributor to the overall caesarean section rate (26.7% of all the caesarean sections). The second and third largest contributors to the overall caesarean section rate were nulliparous women with single cephalic pregnancy at term either in spontaneous labour (group 1) or induced or delivered by caesarean section before labour (group 2), which were responsible for 18.3% and 15.3% of all caesarean deliveries, respectively. The 10-group classification could be easily applied to a multicountry dataset without problems of inconsistencies or misclassification. Specific groups of women were clearly identified as the main contributors to the overall caesarean section rate. This classification could help health care providers to plan practical and effective actions targeting specific groups of women to improve maternal and perinatal care.
    Reproductive Health 10/2009; 6:18. · 1.31 Impact Factor
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    ABSTRACT: An abstract is unavailable. This article is available as HTML full text and PDF.
    Obstetric Anesthesia Digest 05/2008; 28(2):86-87.
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    ABSTRACT: Cluster-based studies involving aggregate units such as hospitals or medical practices are increasingly being used in healthcare evaluation. An important characteristic of such studies is the presence of intracluster correlation, typically quantified by the intracluster correlation coefficient (ICC). Sample size calculations for cluster-based studies need to account for the ICC, or risk underestimating the sample size required to yield the desired levels of power and significance. In this article, we present values for ICCs that were obtained from data on 97,095 pregnancies and 98,072 births taking place in a representative sample of 120 hospitals in eight Latin American countries. We present ICCs for 86 variables measured on mothers and newborns from pregnancy to the time of hospital discharge, including 'process variables' representing actual medical care received for each mother and newborn. Process variables are of primary interest in the field of implementation research. We found that overall, ICCs ranged from a minimum of 0.0003 to a maximum of 0.563 (median 0.067). For maternal and newborn outcome variables, the median ICCs were 0.011 (interquartile range 0.007-0.037) and 0.054 (interquartile range 0.013-0.075) respectively; however, for process variables, the median was 0.161 (interquartile range 0.072-0.328). Thus, we confirm previous findings that process variables tend to have higher ICCs than outcome variables. We demonstrate that ICCs generally tend to increase with higher prevalences (close to 0.5). These results can help researchers calculate the required sample size for future research studies in maternal and perinatal health.
    Paediatric and Perinatal Epidemiology 04/2008; 22(2):117-25. · 2.16 Impact Factor
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    ABSTRACT: To assess the risks and benefits associated with caesarean delivery compared with vaginal delivery. Prospective cohort study within the 2005 WHO global survey on maternal and perinatal health. 410 health facilities in 24 areas in eight randomly selected Latin American countries; 123 were randomly selected and 120 participated and provided data 106,546 deliveries reported during the three month study period, with data available for 97,095 (91% coverage). Maternal, fetal, and neonatal morbidity and mortality associated with intrapartum or elective caesarean delivery, adjusted for clinical, demographic, pregnancy, and institutional characteristics. Women undergoing caesarean delivery had an increased risk of severe maternal morbidity compared with women undergoing vaginal delivery (odds ratio 2.0 (95% confidence interval 1.6 to 2.5) for intrapartum caesarean and 2.3 (1.7 to 3.1) for elective caesarean). The risk of antibiotic treatment after delivery for women having either type of caesarean was five times that of women having vaginal deliveries. With cephalic presentation, there was a trend towards a reduced odds ratio for fetal death with elective caesarean, after adjustment for possible confounding variables and gestational age (0.7, 0.4 to 1.0). With breech presentation, caesarean delivery had a large protective effect for fetal death. With cephalic presentation, however, independent of possible confounding variables and gestational age, intrapartum and elective caesarean increased the risk for a stay of seven or more days in neonatal intensive care (2.1 (1.8 to 2.6) and 1.9 (1.6 to 2.3), respectively) and the risk of neonatal mortality up to hospital discharge (1.7 (1.3 to 2.2) and 1.9 (1.5 to 2.6), respectively), which remained higher even after exclusion of all caesarean deliveries for fetal distress. Such increased risk was not seen for breech presentation. Lack of labour was a risk factor for a stay of seven or more days in neonatal intensive care and neonatal mortality up to hospital discharge for babies delivered by elective caesarean delivery, but rupturing of membranes may be protective. Caesarean delivery independently reduces overall risk in breech presentations and risk of intrapartum fetal death in cephalic presentations but increases the risk of severe maternal and neonatal morbidity and mortality in cephalic presentations.
    BMJ (online) 12/2007; 335(7628):1025. · 17.22 Impact Factor
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    ABSTRACT: Caesarean delivery rates continue to increase worldwide. Our aim was to assess the association between caesarean delivery and pregnancy outcome at the institutional level, adjusting for the pregnant population and institutional characteristics. For the 2005 WHO global survey on maternal and perinatal health, we assessed a multistage stratified sample, comprising 24 geographic regions in eight countries in Latin America. We obtained individual data for all women admitted for delivery over 3 months to 120 institutions randomly selected from of 410 identified institutions. We also obtained institutional-level data. We obtained data for 97,095 of 106,546 deliveries (91% coverage). The median rate of caesarean delivery was 33% (quartile range 24-43), with the highest rates of caesarean delivery noted in private hospitals (51%, 43-57). Institution-specific rates of caesarean delivery were affected by primiparity, previous caesarean delivery, and institutional complexity. Rate of caesarean delivery was positively associated with postpartum antibiotic treatment and severe maternal morbidity and mortality, even after adjustment for risk factors. Increase in the rate of caesarean delivery was associated with an increase in fetal mortality rates and higher numbers of babies admitted to intensive care for 7 days or longer even after adjustment for preterm delivery. Rates of preterm delivery and neonatal mortality both rose at rates of caesarean delivery of between 10% and 20%. High rates of caesarean delivery do not necessarily indicate better perinatal care and can be associated with harm.
    The Lancet 07/2006; 367(9525):1819-29. · 39.21 Impact Factor
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    ABSTRACT: Las tasas de cesáreas continúan incrementándose en todo el mundo. Nuestro objetivo fue investigar la asociación entre frecuencia de cesáreas y resultados del embarazo en el ámbito institucional ajustado a la población de embarazadas y a las características institucionales. Métodos: para el estudio de la OMS del 2005 sobre salud materna y perinatal realizamos un estudio multiestratificado comprendiendo 24 regiones geográficas en 8 países de Latinoamérica. Se obtuvieron datos individuales de todas las mujeres admitidas para el parto durante 3 meses en 120 instituciones seleccionadas aleatoriamente de 410 instituciones identificadas. También se obtuvieron datos del nivel institucional. Conclusiones: Obtuvimos datos de 97.095 partos entre 106.546 (Cobertura del 91%). La mediana de cesáreas fue del 33% (Rango intercuartilos 24 al 43%) con las tasas mas elevadas en hospitales privados, 51% (Rango 43 al 57%). Las tasas de cesáreas especificas de cada institución fueron afectadas por primiparidad, cesárea previa y complejidad institucional. Las tasas de cesáreas fueron positivamente asociadas con tratamiento antibiótico post-parto, severa morbilidad materna y mortalidad, aun ajustándose a los factores de riesgo. El incremento en las tasas de cesáreas fue asociada con aumento en la tasa de mortalidad fetal y mayor número de bebes admitidos en la unidad de cuidados intensivos por 7 días aun después de ajustarse con prematurez. Las tasas de partos pretérminos y muerte neonatal aumentaron en la frecuencia de cesáreas de entre 10 y 20%. Interpretación: Las altas tasas de cesáreas no necesariamente indican mejor cuidado perinatal y pueden asociarse con daños.
    Revista del Hospital Materno Infantil Ramón Sardá. 01/2006;

Publication Stats

480 Citations
99.10 Total Impact Points

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  • 2008
    • Ottawa Hospital Research Institute
      Ottawa, Ontario, Canada
  • 2007
    • University of Oxford
      • Nuffield Department of Obstetrics and Gynaecology
      Oxford, ENG, United Kingdom
  • 2006
    • World Health Organization WHO
      • Department of Reproductive Health and Research (RHR)
      Genève, GE, Switzerland