Risk of Hospital-Acquired Complications in Patients with Chronic Kidney Disease

Abstract

Background and objectives: Unintended injuries or complications in hospitalized patients are common, potentially preventable, and associated with adverse consequences, including greater mortality and health care costs. Patients with CKD may be at higher risk of hospital-acquired complications (HACs).

Design, setting, participants, & measurements: Adults from a population-based cohort (Alberta Kidney Disease Network) who were hospitalized from April 1, 2003, to March 31, 2008, made up the study cohort. Kidney function was defined using outpatient eGFR and proteinuria (protein-to-creatinine ratio or dipstick) in the year before index hospitalization. Comorbid conditions were identified using validated algorithms applied to administrative data. A specific diagnostic indicator was used to identify HACs. Complications were classified into clinically homogeneous groups and subclassified as potentially preventable (p-HACs) or always preventable (a-HACs). Multivariable logistic regressions models were used to examine the association of CKD with HACs, accounting for confounders.

Results: Of 536,549 patients, 8.5% had CKD; those with CKD were older and more likely to be admitted for circulatory system diseases than those without CKD. In fully adjusted models, the odds ratio (OR) of any hospital complication in patients with CKD (reference: no CKD) was 1.19 (95% confidence interval [95% CI], 1.18 to 1.26); there was a graded relation between the risk of HACs and CKD severity, with an OR of 1.81 (95% CI, 1.51 to 2.17) in those with the most severe CKD (eGFR, 15-29 ml/min per 1.73 m(2) and proteinuria, >30 mg/mmol). Findings were similar for p-HACs (OR, 1.20 [95% CI, 1.16 to 1.24] and 1.78 [95% CI, 1.43 to 2.11], respectively). The a-HACs had similar point estimates.

Conclusions: The presence of CKD and its severity are associated with a higher risk of HACs, including those considered preventable. Targeted strategies to reduce complications in patients with CKD admitted to the hospital should be considered.

Keywords: chronic kidney disease; cohort studies; health care costs; hospital acquired complication; hospitalization; humans; medical errors; patient safety; preventable hospital complications; renal insufficiency, chronic.