Schonberger Robert B, Dutton Richard P, Dai Feng
From the *Department of Anesthesiology, Yale School of Medicine, New Haven, Connecticut; †Anesthesia Quality Institute, Schaumburg, Illinois; and ‡Yale Center for Analytical Sciences, Yale School of Public Health, New Haven, Connecticut.
Anesth Analg. 2016 Jan;122(1):243-50. doi: 10.1213/ANE.0000000000000917.
Modifications in physician billing patterns have been shown to occur in response to payer incentives, but the phenomenon remains largely unexplored in billing for anesthesia services. Within the field of anesthesiology, Medicare's policy not to provide additional reimbursement for higher ASA physical status scores contrasts with the practices of most private payers, and this pattern of reimbursement introduces a change in billing incentives once patients attain Medicare eligibility. We hypothesized that, coincident with the onset of widespread Medicare eligibility at age 65 years, a discontinuity in reported ASA physical status scores would be observed after controlling for the underlying trend of increasing ASA physical status scores with age. This phenomenon would manifest as a pattern of upcoding of ASA physical status scores for patients younger than 65 years that would become less common in patients age 65 years and older.
Using data on age, sex, ASA physical status scores, and type of surgery from the National Anesthesia Clinical Outcomes Registry, we used a quasi-experimental regression discontinuity design to analyze whether there was evidence for a discontinuity in reported ASA physical status scores occurring at age 65 years for the nondeferrable anesthesia services accompanying hip, femur, or lower leg fracture repair.
A total of 49,850 records were analyzed. In models designed to detect regression discontinuity at 65 years of age, neither the binary variable "age ≥ 65" nor the interaction term of age × age ≥ 65 was a statistically significant predictor of the outcome of ASA physical status score. The statistical inference was unchanged when ASA physical status scores were reclassified as a binary outcome (I-II vs III-V) and when different bandwidths around age 65 years were used. To test the validity of our study design for detecting regression discontinuity, simulations of the occurrence of deliberate upcoding of ASA physical status scores demonstrated the ability to detect deliberate upcoding occurring at rates exceeding 2% of eligible cases of patients younger than 65 years.
We found no evidence for a significant discontinuity in the pattern of ASA physical status scores coincident with Medicare eligibility at age 65 years for the nondeferrable conditions of hip, femur, or lower leg fracture repair. Our data do not support the presence of fraudulent ASA physical status scoring among National Anesthesia Clinical Outcomes Registry contributors. If deliberate upcoding of ASA physical status scores is present in our data, the behavior is either too rare or too insensitive to the removal of payer incentives at age 65 years to be evident in the present analysis.
已有研究表明，医师计费模式会因支付方的激励措施而发生改变，但在麻醉服务计费方面，这一现象在很大程度上仍未得到充分探索。在麻醉学领域，医疗保险（Medicare）对于较高的美国麻醉医师协会（ASA）身体状况评分不提供额外报销的政策，与大多数私人支付方的做法形成对比，并且一旦患者达到医疗保险资格，这种报销模式就会导致计费激励发生变化。我们推测，在65岁普遍达到医疗保险资格时，在控制了ASA身体状况评分随年龄增长的潜在趋势后，会观察到报告的ASA身体状况评分出现不连续。这种现象将表现为65岁及以上患者中，ASA身体状况评分高报的情况减少，而65岁以下患者中这种情况则较为常见。
利用来自国家麻醉临床结果登记处的年龄、性别、ASA身体状况评分和手术类型数据，我们采用了准实验性回归间断设计，以分析对于髋部、股骨或小腿骨折修复的非延期麻醉服务，在65岁时报告的ASA身体状况评分是否存在不连续的证据。
共分析了49,850条记录。在旨在检测65岁时回归间断的模型中，二元变量“年龄≥65岁”以及年龄×年龄≥65岁的交互项，均不是ASA身体状况评分结果的统计学显著预测因素。当将ASA身体状况评分重新分类为二元结果（I-II级与III-V级），以及使用65岁左右不同的带宽时，统计推断结果不变。为了检验我们检测回归间断的研究设计的有效性，对ASA身体状况评分故意高报情况的模拟显示，能够检测到65岁以下符合条件患者中发生率超过2%的故意高报情况。
对于髋部、股骨或小腿骨折修复的非延期情况，我们没有发现证据表明在65岁达到医疗保险资格时，ASA身体状况评分模式存在显著不连续。我们的数据不支持国家麻醉临床结果登记处的参与者存在欺诈性ASA身体状况评分的情况。如果我们的数据中存在故意高报ASA身体状况评分行为，那么这种行为要么非常罕见，要么对65岁时支付方激励措施的消除不太敏感，以至于在本分析中不明显。
