Ayaz Hyder

Dr. Ayaz Hyder

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Research Focus & Metrics

Academic Career Length

19Years (2008-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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10 June 2011 in Critical Care
Verified
Journal Article
Open access
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OAOmar Alkandari
Omar Alkandari
KEK Allen Eddington
K Allen Eddington
AHAyaz Hyder
Ayaz Hyder
FGFrance Gauvin
France Gauvin
TDThierry Ducruet
Thierry Ducruet
MZMichael Zappitelli
Michael Zappitelli
Introduction: In adults, small (< 50%) serum creatinine (SCr) increases predict mortality. It is unclear whether different baseline serum creatinine (bSCr) estimation methods affect findings of acute kidney injury (AKI)-outcome associations. We characterized pediatric AKI, evaluated the effect of bSCr estimation approaches on AKI-outcome associations and evaluated the use of small SCr increases to predict AKI development. Methods: We conducted a retrospective cohort database study of children (excluding postoperative cardiac or renal transplant patients) admitted to two pediatric intensive care units (PICUs) for at least one night in Montreal, QC, Canada. The AKI definition was based on the Acute Kidney Injury Network staging system, excluding the requirement of SCr increase within 48 hours, which was impossible to evaluate on the basis of our data set. We estimated bSCr two ways: (1) the lowest SCr level in the three months before admission or the average age- and gender-based norms (the standard method) or (2) by using average norms in all patients. Outcomes were PICU mortality and length of stay as well as required mechanical ventilation. We used multiple logistic regression analysis to evaluate AKI risk factors and the association between AKI and mortality. We used multiple linear regression analysis to evaluate the effect of AKI on other outcomes. We calculated diagnostic characteristics for early SCr increase (< 50%) to predict AKI development. Results: Of 2,106 admissions (mean age ± SD = 5.0 ± 5.5 years; 47% female), 377 patients (17.9%) developed AKI (using the standard bSCr method) during PICU admission. Higher Pediatric Risk of Mortality score, required mechanical ventilation, documented infection and having a bSCr measurement were independent predictors of AKI development. AKI was associated with increased mortality (adjusted odds ratio (OR) = 3.7, 95% confidence interval (95% CI) = 2.1 to 6.4, using the standard bSCr method; OR = 4.5, 95% CI = 2.6 to 7.9, using normative bSCr values in all patients). AKI was independently associated with longer PICU stay and required mechanical ventilation. In children with no admission AKI, the initial percentage SCr increase predicted AKI development (area under the curve = 0.67, 95% CI = 0.60 to 0.74). Conclusions: AKI is associated with increased mortality and morbidity in critically ill children, regardless of the bSCr used. Paying attention to small early SCr increases may contribute to early AKI diagnosis in conjunction with other new AKI biomarkers.

1 October 2009 in Kidney International
Verified
Journal Article
Closed access
MZMichael Zappitelli
Michael Zappitelli
PBPierre-Luc Bernier
Pierre-Luc Bernier
RSRichard S. Saczkowski
Richard S. Saczkowski
CTChristo I. Tchervenkov
Christo I. Tchervenkov
RGRonald Gottesman
Ronald Gottesman
OAOmar Alkandari
Omar Alkandari

1 January 2014 in Epidemiology
Verified
Journal Article
Closed access
AHAyaz Hyder
Ayaz Hyder
Hyung LeeHyung Lee
Hyung Lee
KEKeita Ebisu
Keita Ebisu
PKPetros Koutrakis
Petros Koutrakis
KBKathleen Belanger
Kathleen Belanger
Michelle BellMichelle Bell
Michelle Bell
Background: Air pollution may be related to adverse birth outcomes. Exposure information from land-based monitoring stations often suffers from limited spatial coverage. Satellite data offer an alternative data source for exposure assessment. Methods: We used birth certificate data for births in Connecticut and Massachusetts, United States (2000–2006). Gestational exposure to PM2.5 was estimated from US Environmental Protection Agency monitoring data and from satellite data. Satellite data were processed and modeled by using two methods—denoted satellite (1) and satellite (2)—before exposure assessment. Regression models related PM2.5 exposure to birth outcomes while controlling for several confounders. Birth outcomes were mean birth weight at term birth, low birth weight at term (<2500 g), small for gestational age (SGA, <10th percentile for gestational age and sex), and preterm birth (<37 weeks). Results: Overall, the exposure assessment method modified the magnitude of the effect estimates of PM2.5 on birth outcomes. Change in birth weight per interquartile range (2.41 μg/m3) increase in PM2.5 was −6 g (95% confidence interval = −8 to −5), −16 g (−21 to −11), and −19 g (−23 to −15), using the monitor, satellite (1), and satellite (2) methods, respectively. Adjusted odds ratios, based on the same three exposure methods, for term low birth weight were 1.01 (0.98–1.04), 1.06 (0.97–1.16), and 1.08 (1.01–1.16); for SGA, 1.03 (1.01–1.04), 1.06 (1.03–1.10), and 1.08 (1.04–1.11); and for preterm birth, 1.00 (0.99–1.02), 0.98 (0.94–1.03), and 0.99 (0.95–1.03). Conclusions: Under exposure assessment methods, we found associations between PM2.5 exposure and adverse birth outcomes particularly for birth weight among term births and for SGA. These results add to the growing concerns that air pollution adversely affects infant health and suggest that analysis of health consequences based on satellite-based exposure assessment can provide additional useful information.

29 June 2010 in Nephrology Dialysis Transplantation
Verified
Journal Article
Closed access
MZM. Zappitelli
M. Zappitelli
BMB. S. Moffett
B. S. Moffett
AHAyaz Hyder
Ayaz Hyder
SGS. L. Goldstein
S. L. Goldstein
Aminoglycosides (AG) cause acute kidney injury (AKI), but the incidence and severity distribution are unclear, particularly in non-critically ill children. We determined the incidence, severity and risk factors of AG-associated AKI and assessed for associations with longer hospitalization and higher costs. At Texas Children's Hospital, we conducted a retrospective cohort study of children treated with AG for ≥ 5 days in 2005, excluding children with admission primary renal diagnoses. AKI was defined by the paediatric Risk, Injury, Failure, Loss, End Stage Kidney Disease (pRIFLE) and Acute Kidney Injury Network (AKIN) definitions. Multiple logistic and linear regression analyses were used to assess independence of associations with outcomes. Five hundred and fifty-seven children [mean ± SD age = 8.0 ± 5.9 years, 286 (51%) male, 489 (88%) gentamicin] were studied. The AKI rate was 33% and 20% by pRIFLE and AKIN definitions, respectively. Longer treatment, higher baseline estimated glomerular filtration rate, being on a medicine (versus surgical) treatment service and prior AG treatment were independent risk factors for AKI development. AKI by pRIFLE or AKIN was independently associated with longer hospital stay and higher total hospital costs. The pRIFLE definition was more sensitive for AKI detection, but the AKIN definition was more strongly related to outcomes. AKI is common and associated with poorer outcomes in non-critically ill children treated with AG. Future research should attempt to understand how to best define AKI in the non-critical illness paediatric setting.


1 January 2018 in Journal Of Health Care For The Poor and Underserved
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RRRebecca Reno
Rebecca Reno
AHAyaz Hyder
Ayaz Hyder
The objectives of this study were to identify social determinants of health as risk factors for infant mortality, particularly among African Americans, and to determine the extent to which research has demonstrated an association between each social determinant of health and infant mortality. A systematic scoping review was conducted following PRISMA guidelines. Databases searched include: EBSCOhost, CINAHL Plus, PsycINFO, SocINDEX, Social Work Abstracts, and Sociological Collection. Following a three-step selection process conducted by two reviewers, 89 studies were included. The social ecological model was used to categorize both the search terms and the findings. Findings revealed that the majority of studies focused on the individual and public policy levels, and most failed to account for the complexity of the issue. Additional research is needed to explore the social determinants of health that are hypothesized to affect infant mortality across all levels, applying more complex, system-level approaches.