Changes in classifications of chronic lower-limb wound codes in patients with diabetes: ICD-9-CM versus ICD-10-CM.

PURPOSE To enhance the learner's competence with knowledge of changes in classifications of chronic lower limb wound codes from ICD-9-CM to ICD-10-CM in patients with diabetes. TARGET AUDIENCE This continuing education activity is intended for physicians and nurses with an interest in skin and wound care. OBJECTIVES After participating in this educational activity, the participant should be better able to:1. Identify the upcoming transition date and coding differences of ICD-9-CM and ICD-10-CM coding.2. Interpret the author's study population, methods, and design.3. Summarize the author's study findings comparing ICD-9-CM coding to ICD-10-CM coding. ABSTRACT OBJECTIVE To determine the sensitivity and specificity of International Classification of Diseases, Ninth Edition, Clinical Modification (ICD-9-CM) and ICD-10-CM codes for individuals with diabetes and foot ulcers. DESIGN AND METHODS Wound care providers and researchers are concerned about the potential impacts when the United States transitions from ICD-9-CM to ICD-10-CM. To identify the impact on diabetic foot ulcers, health history and wound variables were prospectively assessed with criterion-standard data from a prospective study of 49 patients with 65 foot ulcer episodes representing 81 incident foot ulcers. The ICD-9-CM and ICD-10-CM code sets were mapped to correctly classify individuals with diabetes and foot ulcers. RESULTS Frequencies for health history variables were similar in both systems. The ICD-9 code did not capture any data on laterality (left or right) or ulcer depth/severity. The ICD-9 captured 69 of 81 incident ulcers (85%) and 94% of heel and midfoot ulcers, whereas the ICD-10 code captured 78 of 81 incident ulcers (96%) and all incident heel or midfoot ulcers. Sensitivity and specificity for ulcer characteristics were consistently lower in ICD-9 than in ICD-10. CONCLUSIONS The ICD-9 and ICD-10 are similar for data capture on health history variables, but wound variables are captured more accurately using ICD-10. The increased specificity of ICD-10 for ulcer location and severity improves identification and tracking ulcers during an episode of care.