Administrative data have been used to identify patients with various diseases, yet no prior study has determined the utility of International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM)-based codes to identify CLI patients. CLI cases (n=126), adjudicated by a vascular specialist, were carefully defined and enrolled in a hospital registry. Controls were frequency matched to cases on age, sex and admission date in a 2:1 ratio. ICD-9-CM codes for all patients were extracted. Algorithms were developed using frequency distributions of these codes, risk factors and procedures prevalent in CLI. The sensitivity for each algorithm was calculated and applied within the hospital system to identify CLI patients not included in the registry. Sensitivity ranged from 0.29 to 0.92. An algorithm based on diagnosis and procedure codes exhibited the best overall performance (sensitivity of 0.92). Each algorithm had differing CLI identification characteristics based on patient location. Administrative data can be used to identify CLI patients within a health system. The algorithms, developed from these data, can serve as a tool to facilitate clinical care, research, quality improvement, and population surveillance.
Bibliographical noteFunding Information:
This investigator-initiated study was supported in part by a grant to the University of Minnesota from Aastrom Biosciences (Ann Arbor, MI, USA).
ATH reports research grants from Abbott Vascular, AstraZeneca, ViroMed, and Pluristem, and consulting relationships with Merck and Novartis. The other authors report no conflicts of interest.
© The Author(s) 2014.
- administrative data
- critical limb ischemia
- peripheral artery disease