Background: Chronic kidney disease (CKD) is associated with markedly increased in-hospital morbidity and mortality. Its effect on in-hospital costs for the treatment of coronary heart disease (CHD) has not been assessed that, although it is of interest due to the exponential increase in its prevalence.
Methods: Clinical and costing data were retrospectively assessed from 765 consecutive patients who suffered from CHD requiring percutaneous coronary interventions. Based on their estimated glomerular filtration rate (eGFR), patients were classified in accordance with the National Kidney Foundation. Patient-level in-hospital costs for this single hospitalization were thoroughly calculated from precise in-house assessments for the national DRG database.
Results: In univariate analysis, the average total in-hospital costs increased with each stage of CKD [euro2926; euro3466; euro4208; euro9687 (stages 4 and 5 combined), P < 0.0001]. Treating patients with CKD stages 4 and 5 utilized markedly more resources than patients with ST-elevation myocardial infarction (euro4916), coronary three-vessel disease (euro4659), severely impaired left ventricular function (euro6072) or diabetes (euro4495). Multivariate analyses identified, even after adjustment for confounding comorbidities, that CKD was a significant and independent predictor of in-hospital costs; with each loss of 1 ml/min in the eGFR, the expenses for this hospitalization increased by euro18 (95% CI euro13-23).
Conclusions: Although the absolute amount of costs may vary between different countries, this work showed, for the first time, that in all stages of CKD, there is a significant increase of in-hospital costs when treating patients with both CHD and CKD.