Significant Cost Savings Can Result from Accurate Coding of Carotid Duplex Indications and Elimination of Inappropriate Tests

Abstract

and treatment [2]. Until very recently the volume of imaging studies had been growing at a 6% annual rate for Medicare beneficiaries in the United States [3]. The possible reasons for physicians over utilizing imaging studies is evident in a Rand Corporation study, which showed that 85% of emergency department physicians perceived that unnecessary imaging studies were done mainly for fear of missing low probability diagnoses and fear of litigation [4]. In response to payer and media pressure, there is a national grass roots movement by all healthcare professionals which, seeks to protest healthcare overutilization and misuse [5].Reimbursement by Medicare for Carotid Duplex Ultrasound (CDU) is tied to indications as documented by International Classification of Diseases (ICD) codes. Indications for CDU have been classified as Appropriate (A), Uncertain (U), or Inappropriate (I) by multi-specialty guidelines [6]. We hypothesized that a significant proportion of ICD codes offered as indications for CDU testing in the medical record were being performed for U or I indications. Therefore, we sought to validate the initial ICD codes for CDU by a clinician review of the medical record, re-classify the revised ICD codes according to appropriateness, and estimate the cost savings for Medicare if CDU for I and some U indications were eliminated. MethodsWe reviewed all out-patient Medicare CDU done in 2011 in our Inter Societal Accreditation Commission accredited Vascular Laboratory. All ICD codes from each patient in the study group were recorded. One of the authors (EK) then reviewed each electronic medical record and determined if the ICD code designated as the indication for CDU accurately reflected the clinical scenario. We utilized the multi-specialty guidelines recently published, which indicate indications as appropriate, uncertain or inappropriate to sort the ICD codes [7]. The rate of abnormal CDU in each of these groups was also analyzed. Initial ICD codes and revised ICD codes for CDU were then categorized as A, U, or I. The National Medicare database was then queried for the number of CDU performed in the out-patient setting throughout the United States for calendar year 2011. CDU was identified by the Healthcare Common Procedure Coding System (HCPCS) Codes 93880 and 93882. The Medicare claim units, charges, cost and payment to providers were analyzed. Cost savings (payments) per year were then determined nationally for Medicare patients by postulating elimination of all I and a percentage of U CDU indications.Chi square testing was used to compare the rates of abnormal CDU among individual ICD codes and groups. Fisher exact testing was used on contingency tables with small cell values. The conduct of this study was approved by The Ohio State University Institutional Review Board. It involved only the retrospective collection of existing data in a protected manner and was considered exempt by The Ohio State University.