Mourad Dahhou

McGill University Health Centre, Montréal, Quebec, Canada

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Publications (31)156.37 Total impact

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    ABSTRACT: Mortality has decreased in children with end-stage kidney disease. Decreases in mortality during dialysis and improved graft survival contributed to this improvement. However, it is unknown whether rates of death with graft function have also improved. We measured this in first transplant recipients under 21 years of age registered in the US Renal Data System. Cox models were used with a time-dependent renal replacement therapy modality variable to estimate the hazard ratios (HRs) for death with graft function associated with a 1-year increment in the calendar year of transplant. There were 157,201 person-years of observation among 17,468 recipients, with 82.2% of study time during graft function and 17.8% during dialysis after graft failure. There were 2003 deaths (12.7 deaths per 1000 person-years) overall, of which 985 occurred with graft function (7.6 deaths per 1000 person-years) and 1018 occurred during dialysis after graft failure (36.1 deaths per 1000 person-years). Each 1-year increment in calendar year of first transplant was associated with a significantly lower risk of death, both overall observation (HR 0.97 (0.96, 0.98)) and focusing on time with graft function (HR 0.98 (0.97, 0.99)). Living donation was significantly associated with better survival, whereas dialysis after graft failure was associated with a much higher mortality risk (HR 4.85 (4.40, 5.35)) compared with graft function. Thus, the risk of death with graft function has decreased in children receiving a first kidney transplant. Increasing living donation and minimizing dialysis may further improve outcomes.Kidney International advance online publication, 15 October 2014; doi:10.1038/ki.2014.342.
    Kidney international. 10/2014;
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    ABSTRACT: Several recent "developmental origins" studies have reported increased long-term risks of adiposity, especially truncal adiposity, among children born small for gestational age (SGA). We assessed the effects of SGA birth and weight gain in early infancy on adiposity at age 11.5 y. From a cluster-randomized breastfeeding promotion trial in 17,046 Belarusian children, we measured height, weight, waist and hip circumferences, triceps and subscapular skinfold thicknesses, and bioimpedance measures of percentage body fat at age 11.5 y. Children born SGA (birth weight <10th percentile) and those born large for gestational age (LGA; >90th percentile for gestational age) were compared with those born appropriate for gestational age (AGA). Weight gain from birth to 6 mo was categorized as high (>0.67-SD increase in weight-for-age), low (>0.67-SD decrease in weight-for-age), or normal. Multilevel statistical models accounted for clustered measurement and controlled for maternal and paternal height and body mass index (BMI), maternal education, geographic region, urban compared with rural residence, and the child's exact age at follow-up. Children born SGA had a significantly lower BMI, percentage body fat, and fat mass index than did those born AGA, with a dose-response effect across 2 subcategories of SGA (P < 0.001 for all comparisons). No difference was observed in waist-to-hip ratio, although the subscapular-to-triceps skinfold ratio was slightly but significantly (P < 0.001) higher in children born SGA. Differences among the study groups continued to increase since the previous follow-up at 6.5 y. SGA infants with catch-up growth in the first 3-6 mo had growth and adiposity measures intermediate between those born SGA without catch-up and those born AGA. Opposite effects of similar magnitude were observed in children born LGA. The 11.5-y-old Belarusian children born SGA were shorter, were thinner, and had less body fat than their non-SGA peers, irrespective of postnatal weight gain. The Promotion of Breastfeeding Intervention Trial is registered at www.isrctn.org as ISRCTN-37687716.
    American Journal of Clinical Nutrition 04/2014; · 6.50 Impact Factor
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    ABSTRACT: Despite numerous population-based randomized intervention trials, the impact of such interventions on socioeconomic inequalities has rarely been examined. We used data from a large cluster-randomized trial to assess the impact of a breastfeeding promotion intervention on socioeconomic inequalities in breastfeeding (exclusivity and duration) and in child cognitive ability at early school age. The Promotion of Breastfeeding Intervention Trial (PROBIT) randomized 31 Belarusian maternity hospitals and their affiliated polyclinics either to receive a breastfeeding promotion intervention modelled on the WHO/UNICEF Baby-Friendly Hospital Initiative or to continue the standard practices in effect at the time of randomization. We estimated and compared inequalities in discontinuation of exclusive breastfeeding before 3 months and of any breastfeeding before 12 months and in child verbal IQ at age 6.5 years, across maternal education strata between the two intervention arms.Findings: Socioeconomic inequalities in discontinuing exclusive breastfeeding before 3 months were negligible in the control group. However, graded inequalities by maternal education emerged in the intervention group {relative risk [RR] = 1.12 [95% confidence interval (CI): 1.04, 1.20] for partial university and RR = 1.20 [95% CI: 1.11, 1.31] for secondary education or less vs complete university; risk difference [RD] = 0.06 [95% CI: 0.03, 0.09] and 0.10 [95% CI: 0.06, 0.14], respectively}. For discontinuing any breastfeeding before 12 months, small socioeconomic gradients in the control group were widened in the intervention group (RR = 1.04 and 1.16, respectively, for mothers with secondary education or less). Despite these differential effects on breastfeeding, however, we observed a small, nonsignificant reduction in socioeconomic inequalities in child verbal IQ at age 6.5 years. A population-based intervention to promote breastfeeding slightly widened socioeconomic inequalities in breastfeeding but not those in child cognitive ability.
    International Journal of Epidemiology 03/2014; · 6.98 Impact Factor
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    ABSTRACT: As HLA matching has been progressively de-emphasized in the American deceased donor (DD) kidney allocation algorithm, concerns have been raised that poor matching at first transplant may lead to greater sensitization and more difficulty finding an acceptable donor for a second transplant should the first transplant fail. We compared proportion of total observed lifetime with graft function after first transplant, and waiting times for a second transplant between individuals with different levels of HLA mismatch (MM) at first transplant. We studied patients recorded in the United States Renal Data System (1988-2009) who received a first DD transplant at age ≤21 years (n = 8433), and the subgroup who were listed for a second DD transplant following first graft failure (n = 2498). Compared with recipients of 2-3 MM first grafts, 4-6 MM graft recipients spent 12% less of their time and 0-1 MM recipients 15% more time with a functioning graft after the first transplant (both p < 0.0001); 4-6 MM recipients were significantly less likely (hazard ratio [HR] 0.87 [95% confidence interval 0.76, 0.98]; p = 0.03), and 0-1 MM recipients more likely (HR 1.26 [0.99, 1.60]; p = 0.06) to receive a second transplant after listing. The benefits of better HLA matching at first transplant on lifetime with graft function are significant, but relatively small.
    American Journal of Transplantation 02/2014; · 6.19 Impact Factor
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    ABSTRACT: MTHFD1 1958G>A, a polymorphism in folate metabolism, increases risk of pregnancy complications. A mouse model exhibited developmental defects, increased weight and decreased leukocyte counts. To examine the latter associations, we genotyped 651 women from a premature birth cohort. Prematurity and 1958G>A were not associated. Increases in the inflammatory marker CRP (logistic regression, p=0.055) and BMI (chi-square, p=0.0113) were associated with AA genotype in women with low folate. MTHFD1 1958G>A may influence immune function and obesity.
    Molecular Genetics and Metabolism 12/2013; · 2.83 Impact Factor
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    ABSTRACT: Amniotic fluid embolism (AFE) is a rare but serious cause of maternal mortality whose aetiology remains obscure. Previous population-based studies have reported associations with labour induction and caesarean delivery. We updated a previous analysis based on the US Nationwide Inpatient Sample from 1999 to 2008. We adapted a diagnostic validation algorithm to minimise false-positive diagnoses, along with statistical methods that account for the stratified random sampling design. Of the 8 571 209 deliveries recorded in the database, 276 met our case definition of AFE, of which 62 (22.9% of the 274 with known vital status) were fatal. Significant associations with AFE were observed for medical induction {adjusted odds ratio [aOR] = 1.7 [95% confidence interval (CI) 1.2, 2.5]}, caesarean delivery [aOR = 15.0; 95% CI 9.4, 23.9], instrumental vaginal delivery [aOR = 6.6; 95% CI 4.0, 11.1], and cervical/uterine trauma [aOR = 7.4; 95% CI 3.6, 14.9]. AFE was associated with increases in risk of stillbirth, hysterectomy, maternal death, and prolonged maternal length of delivery hospital stay. AFE remains an extremely serious obstetric complication with high risks of maternal and fetal mortality. The increased risks of AFE associated with labour induction and caesarean delivery have implications for elective use of these interventions.
    Paediatric and Perinatal Epidemiology 09/2013; 27(5):436-41. · 2.16 Impact Factor
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    ABSTRACT: Because the diagnosis of postpartum hemorrhage (PPH) depends on the accoucheur's subjective estimate of blood loss and varies according to mode of delivery, we examined temporal trends in severe PPH, defined as PPH plus receipt of a blood transfusion, hysterectomy, and/or surgical repair of the uterus. We analyzed 8.5 million hospital deliveries in the U.S. Nationwide Inpatient Sample from 1999 to 2008 for temporal trends in, and risk factors for, severe PPH, based on ICD-9-CM diagnosis and procedure codes. Sequential logistic regression models that account for the stratified random sampling design were used to assess the extent to which changes in risk factors explain the trend in severe PPH. Of the total 8,571,209 deliveries, 25,906 (3.0 per 1000) were complicated by severe PPH. The rate rose from 1.9 to 4.2 per 1000 from 1999 to 2008 (P for yearly trend <.0001), with increases in severe atonic and nonatonic PPH, due especially to PPH with transfusion, but also PPH with hysterectomy. Significant risk factors included maternal age ≥35 years [aOR = 1.5 (1.5-1.6)], multiple pregnancy [2.8 (2.6-3.0)], fibroids [2.0 (1.8-2.2)], pre-eclampsia [3.1 (2.9-3.3)], amnionitis [2.9 (2.5-3.4)], placenta previa or abruption [7.0 (6.6-7.3)], cervical laceration [94.0 (87.3-101.2)], uterine rupture [11.6 (9.7-13.8)], instrumental vaginal delivery [1.5 (1.4-1.6)], and cesarean delivery [1.4 (1.3-1.5)]. Changes in risk factors, however, accounted for only 5.6% of the increase in severe PPH. A doubling in incidence of severe PPH over 10 years was not explained by contemporaneous changes in studied risk factors.
    American journal of obstetrics and gynecology 07/2013; · 3.28 Impact Factor
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    ABSTRACT: To compare maternal lipid and lipoprotein concentrations between small for gestational age (SGA) infants and infants with normal growth born at term. This was a case-control study nested within a large (n = 5337) prospective multicenter cohort of pregnant women followed to delivery. SGA cases (n = 323) were all term infants with birth weight below the 10th percentile for their gestational age and sex. Controls (n = 671) were selected at random from term infants with birth weight between the 25th and 75th percentiles. Plasma samples obtained at 24-26 weeks were analyzed for lipoproteins using a recently developed nuclear magnetic resonance-based procedure that distinguishes high-density lipoprotein (HDL) and low-density lipoprotein particles of different sizes. Apolipoprotein A-1 and C-II levels were analyzed using turbidimetric methods. Compared with controls, mothers of SGA cases had significantly higher mean concentrations of total HDL particles, medium and small HDL particles, and apolipoprotein A-1, with evidence of a dose-response relationship across quartiles of the control distribution. aORs for the highest quartiles were 2.8 (95% CI, 1.7-4.5) for total HDL particles and 3.1 (95% CI, 1.9-5.0) for apolipoprotein A-1. Our results suggest that the higher HDL particle and apolipoprotein A-1 concentrations in mothers of SGA cases may reflect defective placental transport of HDL, which could compromise cholesterol uptake by the developing fetus.
    The Journal of pediatrics 06/2013; · 4.02 Impact Factor
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    ABSTRACT: OBJECTIVES:The objective was to examine associations of neonatal weight gain (NWG) and head circumference gain (HCG) with IQ scores and behavior at early school age.METHODS:We used data from the Promotion of Breastfeeding Intervention Trial, involving Belarusian infants born full term and weighing ≥2500 g. NWG and HCG were measured as the percentage gain in weight and head circumference over the first 4 weeks relative to birth size. IQ and behavior were measured at 6.5 years of age by using the Wechsler Abbreviated Scales of Intelligence and the Strengths and Difficulties Questionnaire (SDQ), respectively, with SDQ collected from parents and teachers. The associations between the exposures (NWG, HCG) and children's IQ and SDQ were examined by using mixed models to account for clustering of measurements, and adjustment for potentially confounding perinatal and socioeconomic factors.RESULTS:Mean NWG was 26% (SD 10%) of birth weight. In fully adjusted models, infants in the highest versus lowest quartile of NWG had 1.5-point (95% confidence interval [CI] 0.8 to 2.2) higher IQ scores (n = 13 840). A weak negative (protective) association between NWG and SDQ total difficulties scores was observed for the teacher-reported (β = -0.39, 95% CI -0.71 to -0.08, n = 12 016), but not the parent-reported (β = -0.12, 95% CI -0.39 to 0.15, n = 13 815), SDQ. Similar associations were observed with HCG and IQ and behavior.CONCLUSIONS:Faster gains in weight or head circumference in the 4 weeks after birth may contribute to children's IQ, but reverse causality (brain function affects neonatal growth) cannot be excluded.
    PEDIATRICS 06/2013; · 4.47 Impact Factor
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    ABSTRACT: BACKGROUND: The American deceased-donor (DD) kidney allocation algorithm for children emphasizes the importance of younger donors and shorter waiting times over human leukocyte antigen (HLA) matching. We sought to compare the relative importance of donor age with that of HLA mismatching (MM) on graft survival. METHODS: We studied patients less than 21 years old recorded in the U.S. Renal Data System, who received a first transplant from a DD 5 years old or younger or from a living donor (LD). Using separate Cox proportional hazards models for DD and LD recipients, we estimated the adjusted 5-year probability of graft survival for each donor age-HLA MM combination and compared estimated graft survival across the different HLA MM-donor age combinations. RESULTS: Both donor age and HLA MM were significantly associated with DD graft survival, whereas only HLA MM had a significant association with LD graft survival. Compared with DD grafts from less than 35-year-old 4-6 MM donors, survival was not significantly different for 0-1 and 2-3 MM grafts from 35- to 44-year-old donors or for 0-1 MM grafts from donors 45 years old or older. The most poorly matched grafts from the oldest LD had survival similar to or better than any DD. CONCLUSIONS: Donor age and HLA MM both play important roles in determining DD graft survival. The advantages of younger donors offset the disadvantages of poorer HLA matching, and better HLA matching offsets the disadvantages of older donor age.
    Transplantation 06/2013; · 3.78 Impact Factor
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    ABSTRACT: IMPORTANCE Most children with end-stage kidney disease (ESKD) are treated with dialysis prior to transplant. It is not known whether their outcomes have changed in recent years. OBJECTIVE To determine if all-cause, cardiovascular, and infection-related mortality rates for children and adolescents beginning dialysis improved between 1990 and 2010. DESIGN, SETTING, AND PARTICIPANTS Retrospective cohort study of patients younger than 21 years initially treated with dialysis for ESKD, recorded in the United States Renal Data System between 1990 and 2010. Children with a prior kidney transplant were excluded. We used Cox proportional hazard models to estimate the hazard ratios (HRs) for mortality associated with a 5-year increment in year of ESKD treatment initiation. Primary analyses censored observation at kidney transplant. MAIN OUTCOMES AND MEASURES All-cause, cardiovascular, and infection-related mortality. RESULTS A total of 3450 children younger than 5 years and 19 951 children 5 years or older started dialysis from 1990-2010. Of those younger than 5 years, 705 died during dialysis treatment (98.8/1000 person-years); mortality rates were 112.2 and 83.4 per 1000 person-years in those initiating dialysis in 1990-1994 and 2005-2010, respectively. Of those 5 years and older at treatment initiation, 2270 died during dialysis treatment (38.6/1000 person-years). Their mortality rates were 44.6 and 25.9 per 1000 person-years in those initiating dialysis in 1990-1994 and 2005-2010, respectively. Each 5-year increment in calendar year of dialysis initiation was associated with an adjusted HR of 0.80 (95% CI, 0.75-0.85) among children younger than 5 years at initiation and an HR of 0.88 (95% CI, 0.85-0.92) among those 5 years and older. CONCLUSIONS AND RELEVANCE In the United States, there was a substantial decrease in mortality rates over time among children and adolescents initiating ESKD treatment with dialysis between 1990 and 2010. Further research is needed to determine the specific factors responsible for this decrease.
    JAMA The Journal of the American Medical Association 05/2013; · 29.98 Impact Factor
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    ABSTRACT: Although second-trimester blood corticotrophin-releasing hormone (CRH) levels are robustly associated with preterm birth, the findings with respect to cortisol have been inconsistent, as have been those relating stress hormones to measured stressors and maternal distress. We measured plasma CRH, adrenocorticotrophic hormone (ACTH), cortisol, cortisol-binding globulin, oestradiol and progesterone at 24-26 weeks in a nested case-control study of 206 women who experienced spontaneous preterm birth and 442 term controls. We also related the hormonal levels to measures of environmental stressors, perceived stress and maternal distress (also assessed at 24-26 weeks) and to placental histopathology. With the exception of an unexpectedly low oestradiol : progesterone ratio among cases (adjusted odds ratio = 0.5 [95% confidence interval 0.3, 0.8] for ratios above the median in controls), none of the hormonal measures was independently associated with spontaneous preterm birth; placental histopathological evidence of infection/inflammation, infarction or decidual vasculopathy; or measures of maternal stress or distress. CRH levels were positively associated with cortisol, but not with ACTH, whereas ACTH was also positively associated with cortisol. Our findings suggest an intact pituitary-adrenal axis and confirm the positive feedback effect of cortisol on (placental) CRH. Neither of these hormonal pathways, however, was strongly linked to maternal stress/distress or to the risk of spontaneous preterm birth.
    Paediatric and Perinatal Epidemiology 05/2013; 27(3):237-46. · 2.16 Impact Factor
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    ABSTRACT: Age at transplant and graft failure risk are associated in young kidney transplant recipients. The risk of graft failure may also vary by current age, irrespective of age at transplant. We sought to estimate age-specific graft failure rates in young kidney transplant recipients and to estimate the relative hazards of graft failure at different ages, compared with at the age of 25 to 29 years. We evaluated 90,689 patients recorded in the United States Renal Data System database who received a first transplant when younger than 40 years (1988-2009); 18,310 were younger than 21 years at transplant. Time-dependent Cox models with time-varying covariates were used to estimate the association between age (time-dependent) and death-censored graft failure risk, adjusted for time since transplant and other potential confounders. There were 31,857 graft failures over a median follow-up of 5.9 years (interquartile range, 2.5-10.5 years; maximum, 21.8 years). Crude age-specific graft failure rates were highest in 19 year olds (6.6 per 100 person-years). Compared with individuals with the same time since transplant observed at 25 to 29 years of age, death-censored graft failure rates were highest in 17 to 24 year olds (hazard ratio, 1.20; [95% confidence interval 1.13, 1.27] for 17-20 year olds and 1.20 [1.13, 1.26] for 21-24 year olds; both P<0.0001) and lowest in 5 to 12 year olds (hazard ratio, 0.60; [0.53, 0.68] for 5-9 year olds and 0.56 [0.49, 0.64] for 10-12 year olds; both P<0.0001). Among first kidney transplant recipients younger than 40 years, older adolescents and young adults (17-24 years) have the highest risk of graft failure, irrespective of age at transplant.
    Transplantation 12/2011; 92(11):1237-43. · 3.78 Impact Factor
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    ABSTRACT: Smoking paradoxically increases the risk of small-for-gestational-age (SGA) birth but protects against preeclampsia. Some studies have reported a "U-shaped" distribution of fetal growth in preeclamptic pregnancies, but reasons for this are unknown. We investigated whether cigarette smoking interacts with preeclampsia to affect fetal growth, and compared levels of soluble fms-like tyrosine kinase-1 (sFlt-1), a circulating anti-angiogenic protein, in preeclamptic smokers and non-smokers. From a multicenter cohort of 5337 pregnant women, we prospectively identified 113 women who developed preeclampsia (cases) and 443 controls. Smoking exposure was assessed by self-report and maternal hair nicotine levels. Fetal growth was assessed as z-score of birthweight for gestational age (BWGA). sFlt-1 was measured in plasma samples collected at the 24-26-week visit. In linear regression, smoking and preeclampsia were each associated with lower BWGA z-scores (β = -0.29; p = 0.008, and β = -0.67; p < 0.0001), but positive interaction was observed between smoking and preeclampsia (β = +0.86; p = 0.0008) such that smoking decreased z-score by -0.29 in controls but increased it by +0.57 in preeclampsia cases. Results were robust to substituting log hair nicotine for self-reported smoking and after adjustment for confounding variables. Mean sFlt-1 levels were lower in cases with hair nicotine levels above vs. below the median (660.4 pg/ml vs. 903.5 pg/ml; p = 0.0054). Maternal smoking seems to protect against preeclampsia-associated fetal growth restriction and may account, at least partly, for the U-shaped pattern of fetal growth described in preeclamptic pregnancies. Smoking may exert this effect by reducing levels of the anti-angiogenic protein sFlt-1.
    BMC Pregnancy and Childbirth 11/2011; 11:91. · 2.52 Impact Factor
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    ABSTRACT: Observational (non-experimental) studies of the association between infant feeding and subsequent child or adult behaviour are prone to residual confounding by subtle differences in psychological attributes and interactional styles of mothers who breast feed vs. those who formula-feed. We followed up 13,889 6.5-year-old Belarusian children who participated in a large cluster-randomised trial of a breast-feeding promotion intervention. Behaviour was evaluated using the Strengths and Difficulties Questionnaire (SDQ), completed independently by the children's parents and teachers. We compared the results of experimental (intention-to-treat, ITT) and observational analyses (based on feeding actually received), both adjusted for clustering. Observational analyses were additionally adjusted for geographical region, urban vs. rural residence, child's sex, age at follow-up, birthweight, and maternal and paternal education. No differences between the randomised experimental vs. control groups were observed in ITT analyses. In contrast, small but statistically significant associations with weaning prior to 3 months were observed for parent and teacher SDQ scores on total difficulties, conduct problems and hyperactivity, even after multivariable adjustment. The absence of associations based on ITT analyses, in contrast with the significant associations based on observed breast-feeding duration, strongly suggests that the latter are biased by residual confounding.
    Paediatric and Perinatal Epidemiology 11/2011; 25(6):500-6. · 2.16 Impact Factor
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    ABSTRACT: Immaturity among individuals transferred from pediatric to adult-oriented care at a young age may leave them vulnerable to higher graft failure risks than in individuals transferred older. We sought to determine the impact of age at transfer on renal allograft failure rates. We evaluated graft failure rates among 440 kidney recipients recorded in the UNOS database (1987-2007), who had been transferred from pediatric to adult care. Transfers were identified using the center codes recorded at yearly data collection. Failure rates for those transferred early (<21 yr old) were compared with rates for those transferred late (≥21 yr old); time-dependent Cox models were used to estimate the additional risk of graft failure associated with early vs. late transfer. The age-standardized failure rate was 12.9 per 100 person-years among those transferred early, and 8.7 per 100 person-years among those transferred late. Compared with individuals the same age who had transferred late, graft failure rates were 58% higher ([95% confidence interval: 7%, 134%], p = 0.02) among those who had transferred early. Younger age at transfer to adult care is associated with higher graft failure rates. Transfer to adult-oriented care at <21 yr of age should be undertaken with caution.
    Pediatric Transplantation 08/2011; 15(7):750-9. · 1.50 Impact Factor
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    ABSTRACT: Mortality risk for kidney transplant recipients may change with increasing accumulated exposure to the "transplantation milieu." We sought to characterize changes over time in mortality rate and in age-, sex- and race-standardized mortality ratios (SMR) relative to the general population, and to estimate the association between increasing time since first transplant and mortality risk. A total of 18 911 patients who received a first transplant at <21 years old (1983-2006), and whose data were recorded in the USRDS, were studied. There were 2713 deaths over a median follow-up of 8.9 (interquartile range 4.0-14.5; maximum 23) years. Among those with graft function, mortality was highest in the first post transplant year; beyond the first year of the first transplant, age-adjusted mortality rates and SMRs decreased slightly over follow-up. Cause of death was cardiovascular for 34.6%, infection for 19.5%, malignancy for 5.8%, other for 21.4% and unknown for 18.7%. For every 1-year time increment after the end of the first post transplant year, age-adjusted all-cause and cardiovascular mortality rates fell by 1% (p = 0.06) and 16% (p = 0.007), respectively; infection-related mortality rate did not change over time (p = 0.5). These results suggest that exposure to the transplantation milieu has no cumulative negative effects on cardiovascular health over the long term.
    American Journal of Transplantation 08/2011; 11(11):2432-42. · 6.19 Impact Factor
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    ABSTRACT: To assess risk factors for postpartum hemorrhage (PPH) and the extent to which changes in those risk factors may explain the rising incidence of PPH recently reported from industrialized countries. We carried out a hospital-based cohort study of 103 726 consecutive deliveries from January 1, 1978, to January 31, 2007, from the computerized medical records of a tertiary-care university maternity hospital in Montreal. We examined adjusted odds ratios for any PPH (estimated blood loss > 500 mL for vaginal deliveries, > 1000 mL for Caesarean sections), severe PPH (estimated blood loss ≥ 1500 mL), and PPH accompanied by blood transfusion and/or hysterectomy. Major independent risk factors for PPH included primiparity, prior Caesarean section, placenta previa or low-lying placenta, marginal umbilical cord insertion in the placenta, transverse lie, labour induction and augmentation, uterine or cervical trauma at delivery, gestational age < 32 weeks, and birth weight ≥ 4500 g. An overall increase in rate of PPH over the study period (OR 1.029; 95% CI 1.024 to 1.034 per year) disappeared (OR 0.995; 95% CI 0.988 to 1.001 per year) after inclusion of maternal age, parity, prior Caesarean section, labour induction and augmentation, placenta previa or low-lying placenta, and abnormal placenta, with most of the reduction attributable to rises in previous Caesarean section and labour augmentation. Labour induction, augmentation of labour, and prior Caesarean section are significantly associated with the risk of PPH, and their increase over the study period largely explains the observed rise in PPH.
    Journal of obstetrics and gynaecology Canada: JOGC = Journal d'obstetrique et gynecologie du Canada: JOGC 08/2011; 33(8):810-9.
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    American journal of epidemiology 03/2011; · 5.59 Impact Factor
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    ABSTRACT: Infants who receive prolonged and exclusive breastfeeding grow more slowly during the first year of life than those who do not. However, infant feeding and growth are dynamic processes in which feeding may affect growth, and prior growth and size may also influence subsequent feeding decisions. The authors carried out an observational analysis of 17,046 Belarusian infants who were recruited between June 1996 and December 1997 and who participated in a cluster-randomized trial of a breastfeeding promotion intervention. To assess the effects of infant size on subsequent feeding, the authors restricted the analysis to infants breastfed (or exclusively breastfed) at the beginning of each follow-up interval and examined associations between weight or length at the beginning of the interval and weaning or discontinuation of exclusive breastfeeding by the end of the interval. Smaller size (especially weight for age) was strongly and statistically significantly associated with increased risks of subsequent weaning and of discontinuing exclusive breastfeeding (adjusted odds ratios = 1.2-1.6), especially between 2 and 6 months, even after adjusment for potential confounding factors and clustered measurement. The authors speculate that similar dynamic processes involving infant crying, other signs of hunger, and supplementation/weaning undermine causal inferences about the "effect" of prolonged and exclusive breastfeeding on slower infant growth.
    American journal of epidemiology 03/2011; 173(9):978-83. · 5.59 Impact Factor

Publication Stats

264 Citations
156.37 Total Impact Points

Institutions

  • 2011–2014
    • McGill University Health Centre
      Montréal, Quebec, Canada
  • 2013
    • University of Adelaide
      • School of Population Health
      Adelaide, South Australia, Australia
  • 2010–2011
    • McGill University
      • • Department of Pediatrics
      • • Department of Microbiology and Immunology
      Montréal, Quebec, Canada