Quality and payment: the U.S. experience of typing inpatient and outpatient casemix payments to quality measures and reporting

Introduction Over the past four to five years, the focus in casemix-based payment systems in the United States has shifted more and more towards "value-based-purchasing" and "payfor-performance" measures. The reporting of pre-set quality indicators is now fundamentally in place for both the inpatient prospective-payment system, based on Medicare-Severity Diagnosis Related Groups (MS-DRGs), and, more recently, the outpatient prospective-payment system, based on Ambulatory Payment Classifications (APCs).