Quality metrics in health care refer to a variety of measures used mainly to characterize what should have been done for a patient or the health consequences of what was done. When estimating quality of health care, often many metrics are measured and then combined to provide an overall estimate either at the patient level or at higher levels of accountability, such as the provider organization, insurer, or even geographic area. Racial/ethnic disparities are defined as the mean difference in overall quality between minorities and Whites not justified by underlying health conditions or patient preferences. However, several statistical features of health care quality data have frequently been ignored: quality is a theoretical construct that is not directly observed; the quality metrics are measured on different scales or, if measured on the same scale, have different baseline rates; the structure of the construct is likely multidimensional; and metrics are correlated within-patients. We address these features and utilize multi-dimensional item response theory models to estimate racial/ethnic quality disparities. Quality metrics measured on 93,000 adults with schizophrenia residing in 5 U.S. states illustrate approaches.

翻译：医疗质量指标是指主要用于描述应为患者执行的诊疗措施或这些措施对健康产生的影响的一系列度量。在评估医疗质量时，通常会对多个指标进行测量，然后将其整合以提供患者层面或更高责任层面（如医疗机构、保险公司乃至地理区域）的总体估计。种族/族裔差异被定义为少数族裔与白人群体之间在总体质量上的平均差异，且该差异不能由基础健康状况或患者偏好所解释。然而，医疗质量数据的若干统计特征常被忽略：质量是一个无法直接观测的理论构念；质量指标的测量尺度不同，即使采用相同尺度，其基线发生率也存在差异；该构念的结构可能具有多维性；且不同指标在患者层面存在相关性。本研究针对这些特征，利用多维项目反应理论模型估计种族/族裔质量差异。以居住在美国5个州的93,000名精神分裂症成年患者的质量指标为例，展示了该方法的实际应用。