Hospitalizations Among Adults With CKD in Public Renal Specialty Practices: A Retrospective Study From Queensland, Australia

Rationale & objective: Little is known about hospital admissions in nondialysis patients with chronic kidney disease (CKD) before death or starting kidney replacement therapy (KRT).

Study design: Retrospective observational cohort study.

Setting & participants: Hospitalizations among 7,201 patients with CKD from 10 public renal clinics in Queensland (QLD), enrolled in the CKD.QLD registry starting in May 2011, were followed for 25,496.34 person-years until they started receiving KRT or died, or until June 30, 2018.

Predictors: Demographic and clinical characteristics of patients with CKD.

Outcomes: Hospital admissions.

Analytical approach: We evaluated the association of demographic and clinical features with hospitalizations, length of hospital stay, and cost.

Results: Approximately 81.5% of the patients were admitted at least once, with 42,283 admissions, costing Australian dollars (AUD) 231 million. The average number of admissions per person-year was 1.7, and the cost was AUD 9,060, 10 times and 2 times their Australian averages, respectively. Single (1-day) admissions constituted 59.2% of all the hospital episodes, led by neoplasms (largely chemotherapy), anemia, CKD-related conditions and eye conditions (largely cataract extractions), but only 14.8% of the total costs. Approximately 41% of admissions were >1-day admissions, constituting 85.2% of the total costs, with cardiovascular conditions, respiratory conditions, CKD-related conditions, and injuries, fractures, or poisoning being the dominant causes. Readmission within 30 days of discharge constituted >42% of the admissions and 46.8% costs. Admissions not directly related to CKD constituted 90% of the admissions and costs. More than 40% of the admissions and costs were through the emergency department. Approximately 19% of the hospitalized patients and 27% of the admissions did not have kidney disease mentioned as either principal or associate causes.

Limitations: Variable follow-up times because of different dates of consent.

Conclusions: The hospital burden of patients with CKD is mainly driven by complex multiday admissions and readmissions involving comorbid conditions, which may not be directly related to their CKD. Strategies to prevent these complex admissions and readmissions should minimize hospital costs and outcomes.

Plain-language summary: We analyzed primary causes, types, and costs of hospitalizations among 7,201 patients with chronic kidney disease (CKD) from renal speciality clinics across Queensland, Australia, over an average follow-up of 3.54 years. The average annual cost per person was $9,060, and was the highest in those with more advanced CKD, higher age, and with diabetes. More than 85% of costs were driven by more complex hospitalizations with longer length of stay. Cardiovascular disease was the single largest contributor for hospitalizations, length of hospital stay, and total costs. Readmission within 30 days of discharge, particularly for the same disorder, and multiday admissions should be the main targets for mitigation of hospital costs in this population.