Matthew Weir

Matthew Weir

A phase 3 clinical trial evaluated whether the medication atrasentan could slow the decline of kidney function in adults with IgA nephropathy. Over a 2.5-year treatment period, patients receiving atrasentan experienced a slower decline in their estimated glomerular filtration rate and reduced protein in their urine compared to those receiving a placebo. The medication was well tolerated, and the beneficial effects on kidney function were observed both in patients taking and not taking sodium-glucose cotransporter-2 inhibitors.

Matthew WeirKyla NaylorAmit Garg

A population-based study of nearly 18,000 patients with kidney failure in Ontario, Canada, examined potential sex-based disparities across the pathway to kidney transplantation. The researchers found that female patients were significantly less likely to be referred to a transplant centre for assessment compared to male patients, a disadvantage that became more pronounced with older age. However, once referred, there were no significant differences between sexes in subsequent steps, including living donor contact, waitlisting, or receiving a transplant.

Matthew WeirAmit GargBrad UrquhartPeter Blake

A study of dialysis patients in Ontario, Canada, found that those starting low-dose methotrexate had a more than threefold higher risk of death or serious hospitalization compared to those starting hydroxychloroquine. Nearly 30 percent of patients taking methotrexate experienced severe complications such as sepsis, lung toxicity, or bone marrow suppression within 90 days. These findings suggest that methotrexate should be avoided in the dialysis population in favour of safer alternative medications.

Matthew WeirKyla NaylorAmit Garg

Researchers updated and validated a risk calculator in Ontario, Canada, designed to help patients on dialysis compare their predicted three-year survival with dialysis versus a kidney transplant. The updated tool, which removed race as a variable to avoid clinical bias, demonstrated moderate accuracy in predicting mortality for both treatment groups. This tool can support patients and healthcare providers in making more informed decisions about pursuing kidney transplantation.

Matthew WeirAndrew HousePavel Roshanov

Researchers tested a risk calculator designed to predict major bleeding complications after a kidney biopsy by applying it to a group of patients in Nova Scotia. The calculator, which uses factors like age, weight, and blood counts, accurately identified patients at higher risk for serious bleeding events such as the need for a blood transfusion. These findings suggest the tool can help doctors and patients better assess individual risks and plan for appropriate monitoring after the procedure.

Dervla ConnaughtonMatthew WeirAndrew HouseLakshman GunaratnamAmit GargPavel Roshanov

Researchers used genetic testing to identify the underlying cause of kidney failure in nearly one-quarter of transplant recipients, often leading to a reclassification of their original diagnosis. The study also found that while only four percent of healthy prospective living donors carried high-risk genetic variants, nearly twenty percent of donors who later developed kidney complications carried these variants. These findings suggest that targeted genetic testing could improve the safety of living kidney donation by better identifying high-risk donors.

Dervla ConnaughtonMatthew WeirKyla NaylorAmit Garg

Researchers in Ontario, Canada, found that men who donated a kidney through laparoscopic surgery had a significantly higher risk of requiring scrotal surgery later in life compared to men who did not donate. Over a 20-year period, nearly 14 percent of donors underwent surgery to treat fluid collection in the scrotum, most commonly a procedure called a hydrocelectomy. These findings highlight a specific long-term surgical risk for male living kidney donors that may occur several years after the initial donation.

Matthew WeirAmit Garg

This study evaluated the accuracy of international health database codes for identifying lithium toxicity in older adults admitted to hospitals in Ontario, Canada. Researchers compared diagnostic codes against actual laboratory measurements of blood lithium levels and found that the coding algorithm had moderate sensitivity and high specificity for identifying toxic lithium levels. The presence of these diagnostic codes successfully distinguished patients with high lithium levels and significant increases from baseline from those with normal levels.

Matthew WeirAmit Garg

This protocol describes the design of an ongoing study that aims to identify harmful drug-drug interactions in older adults by analyzing Ontario's administrative healthcare data. Using high-throughput computing, researchers will run thousands of population-based cohort studies to compare health outcomes in patients taking specific drug combinations against those taking only one of the medications. The goal of this project is to generate real-world evidence that can improve prescribing safety and inform regulatory decisions.

Matthew Weir

An economic evaluation using data from a multinational clinical trial linked with Canadian administrative databases assessed the cost-effectiveness of different timing strategies for starting kidney replacement therapy in critically ill patients with severe acute kidney injury. The analysis revealed that waiting for standard indications to start therapy was more expensive per patient than starting immediately, but it generated more quality-adjusted life-years. Overall, the standard initiation strategy was found to be cost-effective, though this result was highly dependent on long-term post-discharge costs and regional rates of ongoing dialysis dependence.

Matthew WeirKyla NaylorAmit GargAndrea Cowan

This is a protocol for an ongoing pilot study that will assess the feasibility of conducting a larger trial to determine if the medication denosumab can prevent bone fractures in patients receiving hemodialysis. Researchers will recruit at least 60 high-risk patients across Ontario to evaluate how well the study procedures work and whether the treatment can be safely integrated into routine care. The findings will help determine if a full-scale study is possible to test a new strategy for reducing the high rate of fragility fractures in this population.

Matthew WeirPavel Roshanov

Researchers conducted a large international trial to determine if the medication spironolactone could reduce the risk of heart failure or cardiovascular death in patients receiving long-term dialysis. The study was stopped early for futility after finding no significant difference in heart-related deaths or hospitalizations between patients taking spironolactone and those taking a placebo. These results suggest that daily use of this specific medication does not provide the expected cardiovascular benefits for the maintenance dialysis population.

Matthew WeirBrad Urquhart

A study of older adults in Ontario found that taking the antibiotic clarithromycin while also using certain blood pressure medications, known as angiotensin receptor blockers, was associated with a higher risk of hospital visits for high potassium levels and acute kidney injury compared to taking azithromycin. This risk of high potassium was even greater for individuals with pre-existing reduced kidney function. These findings suggest a significant drug interaction occurs because clarithromycin interferes with the body's ability to transport and eliminate these blood pressure medications through the liver.

Louise MoistMatthew WeirKyla NaylorAmit GargPavel RoshanovPeter Blake

Researchers in Ontario, Canada, found that deaths among people with advanced chronic kidney disease increased by eight per cent during the first 21 months of the COVID-19 pandemic. Despite this increase in mortality, hospital admissions and emergency room visits for these patients actually decreased, suggesting a significant disruption in how they accessed medical care. Interestingly, visits to kidney specialists remained stable throughout the pandemic, and there was no significant change in the number of patients needing to start urgent dialysis.

Matthew Weir

A study of older adults in Ontario, Canada, found that starting a sodium-glucose cotransporter-2 inhibitor was associated with a lower risk of developing high potassium levels, a common complication for patients taking renin-angiotensin-aldosterone system inhibitors. Additionally, patients who started the sodium-glucose cotransporter-2 inhibitor were less likely to stop taking their renin-angiotensin-aldosterone system inhibitors. These findings suggest that combining these medications in daily clinical practice may help manage potassium levels and allow patients to safely continue their prescribed therapies.

Matthew WeirKyla NaylorAmit Garg

Researchers examined the steps required to receive a kidney transplant across different regional renal programs in Ontario, Canada, and found significant geographic disparities in access. Patients in Northern Ontario were much less likely to be referred for transplant evaluation, find potential living donors, or be placed on the deceased donor waitlist compared to those in Toronto. These findings highlight that even within a publicly funded health care system, a patient's location can greatly influence their ability to receive a kidney transplant.

Louise MoistDervla ConnaughtonMatthew WeirSusan HuangAndrew HouseLakshman GunaratnamArsh JainAmit GargAndrea CowanPavel RoshanovPeter Blake

In a study of 125 adults aged 50 and older with chronic kidney disease, researchers found that genetic testing identified a specific cause of disease in 38% of patients. The highest success rate for diagnosis occurred in those aged 50 to 54, with various forms of glomerular disease being the most common findings. These genetic results led to changes in medical treatment and clinical management, suggesting that age alone should not be a barrier to accessing genetic testing for kidney disease.

Matthew WeirKyla NaylorAmit GargPeter Blake

Researchers in Ontario, Canada, compared the health outcomes of over 31,000 dialysis patients before and during the first three years of the COVID-19 pandemic. While death rates were significantly higher during specific months of the pandemic, the overall mortality rate over the entire 36-month period was not substantially higher than expected. Interestingly, hospitalizations and emergency room visits decreased during the pandemic, yet there was no corresponding increase in deaths unrelated to COVID-19.

Matthew Weir

This secondary analysis of a large clinical trial evaluated whether delaying the start of dialysis in critically ill patients with severe acute kidney injury, who did not have urgent indications for the therapy, affected their survival. Researchers found that longer delays in starting dialysis were not associated with an increased risk of death at 90 days. However, a longer delay was linked to a higher likelihood of remaining dependent on dialysis at 90 days.

Matthew Weir

This protocol describes the design of the Global Kidney Patient Trials Network, an ongoing registry of patients with chronic kidney disease, and the CAPTIVATE trial, an upcoming global adaptive platform clinical trial. The registry has already enrolled over 4,000 participants across eight countries to track clinical characteristics and identify candidates for the trial. The CAPTIVATE trial will evaluate multiple investigational treatments and combinations to determine if they can slow the decline of kidney function in people with chronic kidney disease.

Matthew WeirAmit Garg

A population-based study of older adults with chronic kidney disease in Ontario, Canada, evaluated the safety of higher versus lower doses of oral antiviral medications for herpes infections. While higher doses did not increase the overall risk of hospital visits for encephalopathy or kidney injury when using standard hospital coding, they were associated with a nearly fourfold higher risk of acute kidney injury when evaluated using actual laboratory test values. Although the absolute risk of this complication remained low at less than one percent, the findings suggest that careful dosing of these antiviral medications is important in patients with reduced kidney function.

Louise MoistDervla ConnaughtonMatthew WeirAndrew HouseLakshman GunaratnamArsh JainAndrea CowanPavel Roshanov

Researchers evaluated the impact of a specialized kidney genetics clinic in Canada by providing genetic testing to 300 patients with chronic kidney disease who met specific referral criteria. The study found that using a standardized testing process identified a genetic cause for kidney disease in one-third of the families, with results typically delivered within three months of assessment. These genetic findings frequently led to changes in clinical management, though the researchers noted a significant delay of over ten years between a patient's initial kidney disease diagnosis and their eventual genetic evaluation.

Matthew Weir

This pilot randomized trial evaluated the feasibility of conducting a larger study to determine the best anticoagulation strategy for patients with atrial fibrillation who are receiving dialysis. Researchers successfully enrolled 151 patients across 28 centres in Canada and Australia, assigning them to receive apixaban, warfarin, or no oral anticoagulation. The study demonstrated that recruiting this patient population and maintaining high treatment adherence over 26 weeks is feasible, paving the way for a definitive trial to compare the safety and effectiveness of these strategies.

Matthew Weir

An environmental scan of Canadian adult kidney transplant programs was conducted to evaluate how they manage patients experiencing transplant graft failure. The study revealed significant gaps and inconsistencies in care across the country, particularly regarding structured preparation for returning to dialysis, multidisciplinary care, and psychological support. These findings highlight key areas for quality improvement and underscore the need for standardized clinical guidelines to manage this complex patient population.

Dervla ConnaughtonMatthew WeirSusan HuangAndrew HouseLakshman GunaratnamPavel Roshanov

Researchers analyzed genetic data from patients with chronic kidney disease to investigate why many develop severe hardening of the arteries, known as vascular calcification. They identified specific mutations in the ABCC6 gene in several families, suggesting that inherited genetic factors may directly contribute to this cardiovascular complication. Identifying these genetic causes early could eventually help doctors use targeted therapies to prevent vascular damage and reduce the risk of death in kidney disease patients.

Matthew WeirAmit GargBrad Urquhart

In older adults taking digoxin, starting a course of the antibiotic trimethoprim-sulfamethoxazole was associated with a nearly sixfold higher risk of hospitalization for digoxin toxicity compared to starting amoxicillin. While the absolute risk of this complication remained low at less than one percent, the interaction is clinically significant because digoxin has a narrow safety range. Physicians should consider using alternative antibiotics or reducing the digoxin dose when these medications must be used together.

Matthew Weir

A study of adults on chronic dialysis in Ontario, Canada, evaluated the likelihood of receiving a kidney transplant for people living with HIV compared to those without the virus. Researchers found that when accounting for the competing risk of death, individuals with HIV had a significantly lower chance of receiving a kidney transplant. However, for those who did receive a transplant, having HIV was not associated with poorer long-term transplant survival outcomes.

Dervla ConnaughtonMatthew Weir

A woman who donated a kidney was later found to have a genetic mutation for Alport Syndrome that had initially been classified as a finding of uncertain significance. Five years after her donation, a re-evaluation of her genetic data and family history led to the discovery that the mutation was likely disease-causing, explaining her unexpected decline in kidney function. This case highlights the importance of periodically re-examining genetic test results, especially for potential living kidney donors, as scientific understanding of specific mutations evolves over time.

Matthew Weir

This secondary analysis of a large international trial examined regional differences in how intensive care units manage severe acute kidney injury, focusing on fluid balance and dialysis initiation. Researchers found significant variation across regions, with intensive care units in Australia and New Zealand maintaining a much lower fluid balance and using continuous dialysis far more frequently than those in North America and Europe. After adjusting for patient characteristics, these regional practice variations were associated with better survival rates and shorter hospital stays for patients in Australia and New Zealand.

Matthew WeirAndrew House

A study at a single transplant centre evaluated the outcomes of kidney transplant recipients who received expanded criteria donor organs, comparing those from donors after circulatory death to those from donors after neurologic determination of death. Researchers found that recipients of kidneys from donors after circulatory death experienced significantly higher rates of delayed graft function and lower overall graft survival at one and three years post-transplant. Despite the higher rate of graft loss, there was no significant difference in patient survival between the two groups.

Matthew WeirAmit Garg

This protocol describes an ongoing study designed to use high-throughput computing and automation to conduct over 700 drug-safety cohort studies in older adults with chronic kidney disease in Ontario, Canada. By comparing short-term health outcomes between new users of outpatient medications and similar nonusers across different levels of kidney function, the researchers aim to identify credible drug-safety signals more efficiently. This automated approach using administrative health databases has the potential to improve medication safety and prevent adverse drug reactions in this vulnerable population.

Matthew WeirAmit GargBrad UrquhartPeter Blake

A study of older adults in Ontario, Canada, found that those with chronic kidney disease who started low-dose methotrexate had double the risk of serious adverse events, such as sepsis or lung and liver toxicity, compared to those starting hydroxychloroquine. This risk was even higher for individuals with more advanced kidney impairment, particularly those with an estimated glomerular filtration rate below 45. These findings suggest that the potential for severe complications should be carefully weighed against the benefits when prescribing methotrexate to patients with reduced kidney function.

Matthew Weir

This secondary analysis of a large clinical trial compared the outcomes of critically ill patients with severe acute kidney injury who started treatment with either continuous renal replacement therapy or intermittent hemodialysis. After adjusting for baseline differences between the groups, patients who initially received continuous therapy had a lower risk of death or remaining dependent on dialysis at 90 days. This benefit was primarily driven by a lower rate of ongoing dialysis dependence among those who started with continuous treatment.

Matthew WeirAmit GargBrad Urquhart

This randomized trial investigated whether a highly absorbable form of curcumin could slow the progression of chronic kidney disease in adults with high levels of protein in their urine. Researchers found that taking 90 milligrams of micro-particle curcumin daily for six months did not significantly improve kidney function or reduce protein leakage compared to a placebo. These results suggest that this specific curcumin formulation does not provide measurable benefits for managing albuminuric chronic kidney disease over a short-term period.

Matthew WeirAmit Garg

A study of older adults in Ontario, centreing on those aged 66 and older, found that starting the antibiotic trimethoprim-sulfamethoxazole was associated with a more than threefold increased risk of hospitalization for high potassium levels compared to starting amoxicillin. This risk was particularly pronounced in individuals with pre-existing reduced kidney function. The medication was also linked to higher rates of acute kidney injury and overall hospital admission within two weeks of starting treatment.

Matthew WeirAndrew HouseAmit GargBrad Urquhart

Researchers developed a new laboratory test to measure a molecule called TMAP in the blood and evaluated its potential as a marker for kidney function across several patient groups. The study found that TMAP levels were significantly higher in patients with chronic kidney disease and those receiving dialysis compared to healthy individuals, with levels rising as the kidney's filtering capacity declined. Because TMAP was also found in other species and even in maple tree sap, it appears to be part of a biological process that is widely conserved across nature.

Matthew WeirDanielle NashAmit GargAndrea Cowan

A study of older adults in Ontario found that while the overall risk of developing low blood calcium after starting the medication denosumab is low, it increases significantly for those with advanced kidney disease or those on dialysis. For patients with the lowest kidney function, nearly one in four experienced mild low calcium and about fifteen percent experienced severe cases. These findings suggest that kidney function and baseline calcium levels are critical factors for doctors to monitor when prescribing this bone-strengthening treatment.

Matthew Weir

This study analyzed data from a large clinical trial to determine if pre-existing chronic kidney disease influenced how the timing of starting dialysis affected recovery in critically ill patients with acute kidney injury. Researchers found that starting dialysis early did not improve survival for patients with or without pre-existing kidney disease, but it did significantly increase the risk of remaining dependent on dialysis at 90 days for those who already had chronic kidney disease. These findings suggest that a more conservative, standard approach to starting dialysis may be safer for patients with pre-existing kidney disease.

Matthew Weir

A Bayesian reanalysis of the STARRT-AKI trial evaluated the timing of starting kidney-replacement therapy in critically ill patients with acute kidney injury. The analysis found a very low probability that starting therapy early provides any clinically important survival benefits compared to a standard approach. Furthermore, patients who received the accelerated strategy spent fewer days alive and free of kidney-replacement therapy, suggesting that an early initiation strategy should not be routinely adopted.

Matthew WeirAmit Garg

A study of older adults with advanced chronic kidney disease in Ontario, Canada, evaluated the safety of fluoroquinolone antibiotics prescribed at higher versus lower doses. Researchers found that patients prescribed a higher-than-recommended dose had a significantly higher risk of experiencing a hospital visit for serious adverse events, including nervous system or psychiatric disorders, low blood sugar, or collagen-associated events. Although the absolute risk of these events remained low at less than two percent, the findings highlight the importance of careful dose adjustment in patients with reduced kidney function.

Matthew WeirAmit GargPeter Blake

A study of older adults with chronic kidney disease in Ontario, Canada, found that starting the gout medication allopurinol at a dose higher than 100 milligrams per day was associated with a more than twofold increased risk of hospitalisation for severe skin reactions compared to starting at a lower dose. This higher starting dose was also linked to an increased risk of overall hospitalisation, though not to a higher risk of death. These findings support the practice of initiating allopurinol at lower doses in patients with reduced kidney function to prevent serious adverse events.

Matthew WeirKyla NaylorAmit GargAndrea Cowan

Researchers compared the risk of bone fractures between older adults in Ontario starting sodium-glucose cotransporter-2 inhibitors and those starting dipeptidyl peptidase-4 inhibitors. The study found no significant difference in fracture risk between the two medication groups over one year, regardless of the patient's baseline kidney function. These findings suggest that this class of diabetes medication does not increase the risk of skeletal injuries in patients with chronic kidney disease.