Inpatient Healthcare Use among Children and Adolescents with CKD

Chronic kidney disease (CKD) is a continuing public health problem. CKD is a progressive disease and children with CKD may progress to kidney failure requiring dialysis or kidney transplantation. Pediatric patients whose CKD does not progress to kidney failure nevertheless face multiple chronic ailments, including hypertension, cardiovascular disease, difficulties in growth, anomalies in electrolyte levels, and metabolic bone disease. Children with CKD are also at risk for acute deterioration in health secondary to infection, dehydration, and side effects associated with medications.

There are few data available on outcomes needed resources of hospitalized pediatric patients with CKD. Zubin J. Modi,  MD, and colleagues conducted a cross-sectional national survey of inpatient healthcare use of children and adolescents with CKD. The researchers sought to generate a description of pediatric discharges associated with CKD compared with pediatric discharges associated with other chronic conditions and to improve understanding of the use of healthcare resources and outcomes of pediatric hospitalizations associated with CKD, including length of stay, cost, and mortality compared with pediatric hospitalizations associated with other chronic illnesses. Results of the study were reported in the American Journal of Kidney Diseases [2021;77(4):500-508].

The study utilized deidentified data from the Agency for Healthcare Research and Quality’s Healthcare Cost and Utilization Project Kids’ Inpatients Database (HCUP-KID), a comprehensive all-payer database of inpatient discharges for children in the United States. The researchers examined HCUP-KID survey years 2006, 2009, 2012, and 2016.

During those survey years, there were an estimated cumulative 6,524,745 discharges with a chronic medical condition nationally; of those, 256,200 were discharges of patients with CKD. Mean age of the cohort with CKD was 9.9 years, 51.5% (n=131,639) were boys,, 49.1% (n=108,261) were White, 18.0% (n=39,716) were Black, 23.8% (n=52,459) were Hispanic, 3.1% (n=6817) were Asian American, 0.8% (n=1812) were Native American, and 5.1% (n=11,292) were other race/ethnicity.

Discharges associated with CKD accounted for 427,845 (95% confidence interval [CI], 391,411-464,279) hospital days per cohort year. Median length of stay in children discharged with CKD was significantly longer compared with children in non-CKD-related discharges (2.8 days vs 1.8 days). Mean length of stay was also longer in CKD-related discharges than in non-CKD-related discharges (6.7 [95% CI, 6.50-6.8] days vs 4.9 [95% CI, 4.8-5.0] days). In multivariate analyses, discharges with CKD had a 29.9% longer length of stay overall. The length of stay for both CKD and non-CKD discharges remained stable during the four cohort years.

Costs were higher among discharges with CKD than among discharges without CKD (median, $8755 vs $5016). Mean cost for all discharges with CKD was $1.33 (95% CI, $1.19-$1.46) billion per cohort year. Over the subsequent cohort years, costs trended up; CKD discharges increased significantly faster than other chronic disease discharges. On average, discharges with CKD had 61.3% higher costs than those without CKD. The significant interaction revealed that the magnitude of this difference increased over time, from 51.0% to 72.5% in 2016.

The presence of CKD was associated with higher risk for mortality (odds ratio, 1.51; 95% CI, 1.40-1.63). The proportion of in-hospital mortality in the presence of CKD was nearly double that of other chronic diseases (0.9% vs 0.5%).

In sensitivity analyses, discharges where CKD was a primary diagnosis had longer length of stay, higher cost, and greater mortality than both discharges with a secondary CKD diagnosis and non-CKD-related discharges. However, longer length of stay was attributable to discharges with a primary CKD diagnosis but not a secondary CKD diagnosis. Costs were higher for both primary and secondary CKD diagnoses (67.4% [95%CI, 62.8%-72.1%] and 44.6% [95% CI, 39.2%-50.3%] higher, respectively, compared with discharges with no CKD diagnosis).

A small portion of overall discharges with CKD had data available on CKD stage. The difference in length of stay between CKD and non-CKD discharges increased in a relatively stepwise manner with advancing CKD stage. Cost difference compared with discharges without CKD was lowest in CKD stage 1 (36.1% [95% CI, 11.9%-65.6%] greater) and highest in CKD stage 5 or kidney failure with replacement therapy (133.2% [95% CI, 120.2%-145.5%] greater). The odds of mortality were higher in CKD stage 3 or higher, stage not specified, and other CKD discharges, than in non-CKD discharges.

The researchers cited some limitations to the study findings, including lack of access to and adjustment for confounders including data on patient readmission and laboratory values.

In summary, the authors said, “In four cohort years between 2006 and 2016, there were 250,000 discharges in the United States due to or complicated by pediatric CKD. Pediatric hospitalizations caused or complicated by CKD were associated with longer length of stay, higher hospitalization-associated costs, and increased odds of mortality compared with hospitalizations without diagnosed CKD. These outcomes seem to be due to the higher complexity of CKD discharges compared to discharges with other chronic illnesses.

“Investigation is needed to identify modifiable patient characteristics and healthcare delivery to reduce the adverse health outcomes of pediatric CKD in the United States. It is highly likely that the costs reported represent only a small portion of pediatric CKD expenditures because much of CKD care is performed on an outpatient basis. Further investigation into direct medical and individual costs to families of children with CKD are needed to fully grasp the economic burden that pediatric CKD has on families and the healthcare system at large.”

Takeaway Points

1. Researchers reported results of a cross-sectional national survey of hospital discharges in pediatric patients with chronic kidney disease (CKD) in comparison with children and adolescents with other chronic illnesses.
2. Pediatric patients with CKD had longer length of stay, higher median costs, and increased risk of mortality compared with patients without CKD.
3. In sensitivity analyses, discharges with CKD as the primary diagnosis had longer length of stay, higher costs, and increased mortality compared with discharges with secondary CKD diagnosis as well as non-CKD discharges.