Dismuke Clara E
Center for Health Economic and Policy Studies and Department of Health Administration and Policy, Medical University of South Carolina, Charleston 29425, USA.
Med Care. 2005 Jul;43(7):713-7. doi: 10.1097/01.mlr.0000167175.72130.a7.
ICD-9-CM procedure codes in inpatient claims data are used for a wide range of purposes, such as monitoring utilization, costs, and quality, and adjusting for patient risk. However, many procedures may be underreported because they are not required for reimbursement via Diagnosis-Related Group (DRG) assignment (non-DRG procedures).
This study examined the extent and variability of ICD-9-CM procedure code reporting for 2 commonly employed non-DRG imaging procedures, computerized tomography (CT) and magnetic resonance imaging (MRI).
Using nonfederal hospital inpatient claims (n = 56,091) from Washington State Inpatient Data for 1997, ICD-9-CM procedure and Universal Billing revenue codes for CT and MRI were compared by payer and hospital characteristics.
When compared with revenue codes, ICD-9-CM procedure coding was found to be considerably underreported and variable, with only 33% of CT and 43% of MRI procedures being recorded. Moreover, the frequency of underreporting of both procedures did not appear to be random, with 31 of 72 hospitals that reported revenue codes for the CT not recording any ICD-9-CM codes for the procedure. Of the 48 hospitals that reported revenue codes for the MRI, 15 failed to record any ICD-9-CM codes that indicated its use. Statistically significant differences in median coding frequencies by teaching and rural status were found for both procedures, while ownership was an important factor in CT reporting variability.
This nonrandom variability in reporting can potentially bias utilization studies as well as risk-adjustment outcome estimates of techniques that rely on reporting of these procedures (eg, APR-DRG and AHRQ CCS). An effort to define a universally agreed upon list of non-DRG procedures to be coded in all US hospitals would greatly improve the capacity of health services researchers to conduct important utilization, outcome and policy studies.
住院索赔数据中的国际疾病分类第九版临床修订本（ICD-9-CM）手术编码用于多种目的，如监测医疗服务利用情况、成本和质量，以及对患者风险进行调整。然而，许多手术可能报告不足，因为通过诊断相关分组（DRG）分配进行报销时不需要这些手术编码（非DRG手术）。
本研究调查了两种常用的非DRG成像手术——计算机断层扫描（CT）和磁共振成像（MRI）的ICD-9-CM手术编码报告的程度和变异性。
利用1997年华盛顿州住院患者数据中的非联邦医院住院索赔（n = 56,091），按付款人和医院特征比较了CT和MRI的ICD-9-CM手术编码及通用计费收入编码。
与收入编码相比，发现ICD-9-CM手术编码报告严重不足且存在变异性，CT手术仅有33%被记录，MRI手术仅有43%被记录。此外，这两种手术的报告不足频率似乎并非随机出现，在报告了CT收入编码的72家医院中，有31家未记录该手术的任何ICD-9-CM编码。在报告了MRI收入编码的48家医院中，有15家未记录任何表明使用该手术的ICD-9-CM编码。两种手术在教学医院和农村医院的编码频率中位数上均存在统计学显著差异，而医院所有权是CT报告变异性的一个重要因素。
这种报告中的非随机变异性可能会使利用研究以及依赖这些手术报告的技术（如APR-DRG和AHRQ CCS）的风险调整结果估计产生偏差。努力确定一份所有美国医院都应编码的非DRG手术的普遍认可清单，将大大提高卫生服务研究人员开展重要的利用、结果和政策研究的能力。
