OBJECTIVE:This paper reviews experience, in both research and application, with measures of appropriateness applied to the utilization of hospital inpatient services in the UK. BACKGROUND:The evolution of different methods for measuring appropriateness of use and the associated reasons for misutilization are described. RESEARCH AND APPLICATION: Recent research developments and applications are outlined and discussed. CONCLUSION:Contemporary enthusiasm with "Diagnosis Independent Explicit Criteria Utilization Review Instruments" is observed and some of the underlying influences are explored.