Ariella Mermelstein, MA

Data Analyst

Ariella Mermelstein

Ariella joined RRI as a data analyst in 2020 while completing her master's degree in mathematics from the Katz School at Yeshiva University. As an integral part of the research division at RRI, Ariella collaborates across all teams on various projects, particularly the physiological effects of hemodialysis on a variety of patient populations. The scope of her work includes predictive modeling, outcome analysis, and data extraction and processing. She has submitted manuscripts for publication and is looking forward to her continued career at RRI.

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Recent Articles by Ariella Mermelstein, MA

  • Clinical journal of the American Society of Nephrology
    June 11, 2024
    Effects of individualized anemia therapy on hemoglobin stability: a randomized controlled pilot trial in hemodialysis patients
    Doris H Fuertinger, Lin-Chun Wang, David J Jörg, Lemuel Rivera Fuentes, Xiaoling Ye, Sabrina Casper, Hanjie Zhang, Ariella Mermelstein, Alhaji Cherif, Kevin Ho, Jochen G Raimann, Lela Tisdale, Peter Kotanko, Stephan Thijssen
    No abstract available
  • Clinical journal of the American Society of Nephrology
    April 19, 2023
    Ultrafiltration Rate Levels in Hemodialysis Patients Associated with Weight-Specific Mortality Risks
    Ariella Mermelstein, Jochen G Raimann, Yuedong Wang, Peter Kotanko, John T Daugirdas
    RESULTSIn the studied 396,358 patients, the average ultrafiltration rate in ml/h was related to postdialysis weight (W) in kg: 3W+330. Ultrafiltration rates associated with 20% or 40% higher weight-specific mortality risk were 3W+500 and 3W+630 ml/h, respectively, and were 70 ml/h higher in men than in women. Nineteen percent or 7.5% of patients exceeded ultrafiltration rates associated with a 20% or 40% higher mortality risk, respectively. Low ultrafiltration rates were associated with subsequent weight loss. Ultrafiltration rates associated with a given mortality risk were lower in high-body weight older patients and higher in patients on dialysis for more than 3 years.CONCLUSIONSUltrafiltration rates associated with various levels of higher mortality risk depend on body weight, but not in a 1:1 ratio, and are different in men versus women, in high-body weight older patients, and in high-vintage patients.BACKGROUNDWe hypothesized that the association of ultrafiltration rate with mortality in hemodialysis patients was differentially affected by weight and sex and sought to derive a sex- and weight-indexed ultrafiltration rate measure that captures the differential effects of these parameters on the association of ultrafiltration rate with mortality.METHODSData were analyzed from the US Fresenius Kidney Care (FKC) database for 1 year after patient entry into a FKC dialysis unit (baseline) and over 2 years of follow-up for patients receiving thrice-weekly in-center hemodialysis. To investigate the joint effect of baseline-year ultrafiltration rate and postdialysis weight on survival, we fit Cox proportional hazards models using bivariate tensor product spline functions and constructed contour plots of weight-specific mortality hazard ratios over the entire range of ultrafiltration rate values and postdialysis weights (W).
  • eLife
    August 9, 2022
    Modeling osteoporosis to design and optimize pharmacological therapies comprising multiple drug types
    David J Jörg, Doris H Fuertinger, Alhaji Cherif, David A Bushinsky, Ariella Mermelstein, Jochen G Raimann, Peter Kotanko
    Our bones are constantly being renewed in a fine-tuned cycle of destruction and formation that helps keep them healthy and strong. However, this process can become imbalanced and lead to osteoporosis, where the bones are weakened and have a high risk of fracturing. This is particularly common post-menopause, with one in three women over the age of 50 experiencing a broken bone due to osteoporosis. There are several drug types available for treating osteoporosis, which work in different ways to strengthen bones. These drugs can be taken individually or combined, meaning that a huge number of drug combinations and treatment strategies are theoretically possible. However, it is not practical to test the effectiveness of all of these options in human trials. This could mean that patients are not getting the maximum potential benefit from the drugs available. Jörg et al. developed a mathematical model to predict how different osteoporosis drugs affect the process of bone renewal in the human body. The model could then simulate the effect of changing the order in which the therapies were taken, which showed that the sequence had a considerable impact on the efficacy of the treatment. This occurs because different drugs can interact with each other, leading to an improved outcome when they work in the right order. These results suggest that people with osteoporosis may benefit from altered treatment schemes without changing the type or amount of medication taken. The model could suggest new treatment combinations that reduce the risk of bone fracture, potentially even developing personalised plans for individual patients based on routine clinical measurements in response to different drugs.
  • Kidney international reports
    April 22, 2022
    Ultrafiltration Rate Thresholds Associated With Increased Mortality Risk in Hemodialysis, Unscaled or Scaled to Body Size
    Jochen G Raimann, Yuedong Wang, Ariella Mermelstein, Peter Kotanko, John T Daugirdas
    RESULTSIn the studied 2542 patients, UFR not scaled to body weight was strongly associated with MHR, whereas postdialysis weight was inversely associated with MHR. MHR crossed 1.5 when unscaled UFR exceeded 1000 ml/h, and this relationship was largely independent of postdialysis weight in the range of 80 to 140 kg. A UFR warning level associated with a lower MHR of 1.3 would be 900 ml/h, whereas the UFR associated with an MHR of 1.0 was patient-size dependent. The MHR when exceeding a UFR threshold of 13 ml/h per kg was dependent on patient weight (MHR = 1.20, 1.45, and >2.0 for a 60, 80, and 100 kg patient, respectively).CONCLUSIONUFR thresholds based on unscaled UFR give more uniform risk levels for patients of different sizes than thresholds based on UFR/kg.INTRODUCTIONOne proposed threshold ultrafiltration rate (UFR) of concern in hemodialysis patients is 13 ml/h per kg. We evaluated associations among UFR, postdialysis weight, and mortality to determine whether exceeding such a threshold would result in similar levels of risk for patients of different body weights.METHODSData were analyzed in this retrospective cohort study for 1 year following dialysis initiation (baseline) and over 2 years of follow-up in incident patients receiving thrice-weekly in-center hemodialysis. Patient-level UFR was averaged over the baseline period. To investigate the joint effect of UFR and postdialysis weight on survival, we fit Cox proportional hazards models using bivariate tensor product spline functions, adjusting for sex, race, age, diabetes, and predialysis serum albumin, phosphorus, and systolic blood pressure (BP). We constructed contour plots of mortality hazard ratios (MHRs) over the entire range of UFR values and postdialysis weights.