The research team, led by Leonard D. Browne and Austin G. Stack of the University of Limerick, together with colleagues at University College Cork, the University of Bristol and partner hospitals, performed a retrospective cross-sectional study of every hospital discharge in the Republic of Ireland recorded in 2022. They used the Hospital In-Patient Enquiry database, known as HIPE, which captures demographic, clinical and administrative information on all admissions to Irish public hospitals. To isolate the specific contribution of chronic kidney disease, the researchers excluded infant admissions and cases in which dialysis or kidney transplantation were the principal reason for the stay, since those represent the treatment of established kidney failure rather than the broader disease spectrum.

The headline figures are striking. A total of 35,409 hospitalisations involving 24,110 individual patients were linked to chronic kidney disease, accounting for 422,738 bed-days and €320.3 million in expenditure. The mean length of stay was 11.9 days, far longer than the typical acute admission, which reflects the complexity of patients whose failing kidneys interact with heart disease, diabetes, infection and other organ dysfunction. Men accounted for the majority of admissions at 58.9 percent and a similar share of costs at 59.9 percent, while patients aged 75 to 84 years represented the largest single group, responsible for 30.0 percent of admissions and 30.8 percent of total expenditure.

Perhaps the most consequential finding for health service planners is the dominance of emergency admissions. Some 71.2 percent of kidney disease-related hospitalisations arrived through emergency departments rather than planned pathways, and 69 percent of the patients held medical cards, an Irish means-tested entitlement that signals substantial socioeconomic disadvantage. Emergency-driven care is inherently more expensive and less efficient than scheduled management, and its predominance suggests that many patients are reaching hospital only after their condition has deteriorated to a crisis point, rather than being stabilised through earlier outpatient intervention.

The study also mapped the clinical company that chronic kidney disease keeps. Among patients whose records carried a CKD code, diabetic nephropathy was the most common accompanying diagnosis at 49.5 percent, followed by tubulo-interstitial diseases at 9.1 percent, other disorders of the kidney and ureter at 6.7 percent, and glomerular diseases at 4.3 percent. That nearly half of these hospitalised patients had diabetes-related kidney damage underscores the entanglement of two of the fastest-growing chronic disease epidemics, and it points directly at prevention opportunities in diabetes management.

When chronic kidney disease appeared as a secondary diagnosis rather than the principal reason for admission, the pattern of primary conditions was revealing. Standardised to rates per 100,000 population, the leading principal diagnoses were disorders of the urinary system at 6,442, acute kidney failure at 3,764, type 1 diabetes at 2,540, type 2 diabetes at 2,489, heart failure at 2,362, other sepsis at 2,199, acute lower respiratory infections at 1,831, and unspecified pneumonia at 1,710. In other words, kidney disease shadows the conditions that fill acute medical wards: infections, cardiac decompensation and metabolic crises. This is the clinical signature of a multisystem disease, one in which declining renal function amplifies risk across the cardiovascular, immune and metabolic systems.

To move beyond simple description, the researchers applied formal statistical modelling. They used generalised linear models to examine associations between patient characteristics and continuous outcomes such as length of stay and cost, and multivariate logistic regression to probe the odds of inpatient death. Three factors emerged as independent drivers of worse outcomes across the board: increasing age, higher scores on the Elixhauser comorbidity index, a widely used weighted measure that tallies the burden of coexisting conditions, and the presence of acute kidney injury, the abrupt deterioration of renal function that frequently complicates hospital stays in patients with pre-existing chronic disease.

The independent association of acute kidney injury with longer stays, higher costs and greater mortality carries a specific clinical message. Acute kidney injury is often preventable through careful medication management, adequate hydration and vigilant monitoring during illness, and patients with chronic kidney disease are particularly vulnerable to it. The finding suggests that inpatient care pathways specifically designed to protect vulnerable kidneys, sometimes called kidney-sparing protocols, could yield measurable savings in both bed-days and lives. It also reinforces the idea that chronic kidney disease should not be managed in isolation but integrated within broader chronic disease programmes that address diabetes, cardiovascular risk and infection prevention together.

The financial arithmetic gives the findings their policy weight. At €320.3 million for a single year, kidney disease-related hospitalisation represents a substantial slice of Irish acute hospital spending, and the concentration of that spending in older, multimorbid patients means the burden is likely to grow as the population ages. The authors argue that integrating chronic kidney disease management within existing chronic disease programmes, alongside preventive strategies and optimised inpatient care pathways, offers realistic opportunities to ease the broader healthcare burden and improve patient outcomes. Earlier detection and management in primary care, they suggest, could shift care away from expensive emergency admissions.

The study was supported with funding from the Health Research Board under a grant examining disparities in health outcomes of chronic kidney disease between men and women in the Irish health system, and it used strictly controlled anonymised files provided by the Healthcare Pricing Office through the National Kidney Disease Surveillance System. Ethical approval was granted by the University Hospital Limerick Research Ethics Committee, with the requirement for explicit consent waived because the dataset was fully anonymised. The authors declare no competing interests. For a country grappling with hospital overcrowding and rising chronic disease, the message of this analysis is unambiguous: the kidneys may be small organs, but the cost of ignoring their failure is written in hundreds of thousands of bed-days and hundreds of millions of euro every year.

Subject of Research: Hospitalisation burden, mortality and costs of chronic kidney disease in Ireland

Article Title: The Hospital Burden of Chronic Kidney Disease in Ireland: A National Analysis of Healthcare Utilisation, Mortality and Costs

Article References: Browne, L. D., O’Keeffe, L. M., Buckley, C. M., Eustace, J. A., & Stack, A. G. (2026). The Hospital Burden of Chronic Kidney Disease in Ireland: A National Analysis of Healthcare Utilisation, Mortality and Costs. BMC Health Services Research. https://doi.org/10.1186/s12913-026-15681-x

Image Credits: AI Generated

DOI: 10.1186/s12913-026-15681-x

Keywords: chronic kidney disease, hospitalisation, healthcare costs, acute kidney injury, Ireland, HIPE database, diabetic nephropathy, inpatient mortality, length of stay, multimorbidity, health services research, emergency admissions