Analysis of primary and secondary APR-DRG codes of an ischemic stroke admission

Authors: Dewilde S, Annemans L, Thijs V
Published in: Value in Health. 2015 Nov;18(7):A400

Abstract

Objectives: To investigate the factors influencing the Severity of illness index of the All Patient Refined DRGs (APR-DRG) classification of patients experiencing an ischemic stroke.

Methods: We conducted a retrospective analysis of ischemic stroke patients classified as “APR-DRG 045: CVA & Precerebral Occlusion with Infarct” between 2005-2007 admitted to the leading teaching hospital in Belgium. Each admission was assigned a primary diagnosis, followed by one or more secondary diagnoses. Based on an algorithm combining these diagnoses a SOI level was assigned to each hospitalization, informing the payment/reimbursement for each admission. This classification allows for the relative comparison of patient subgroups within each APR-DRG and severity subclass, and was designed to reflect the relative resources required for treatment, enabling for the casemix adjustment of the payment/reimbursement system.

Results: 1,107 stroke admissions were recorded during the study period, distributed across four SOI categories: 2% minor, 44% moderate, 36% major, 18% severe. No relationship was found between the type of primary diagnosis and the SOI level. Of the 1,407 secondary diagnoses assigned in the dataset, only half (783) were specific to one single SOI category; all others were found in 2, 3 or even 4 SOI levels. However a significantly positive relationship was found between the average number of secondary diagnoses assigned per patient and the SOI: on average 5.9, 11.3, 19.4 and 25.6 secondary diagnoses were allocated for increasing levels of SOI. Secondary diagnoses such as MI, diabetes, atrial fibrillation, hypertension, hypercholesterolemia, smoking, atherosclerosis were individually not linked to more severe levels of SOI, however the combination of these factors did affect a patient’s SOI.

Conclusions: Payment/ reimbursement decisions for patients experiencing an ischemic stroke will be based on the resources necessary to manage a case mix of secondary diagnoses rather than be informed by the severity of the stroke.