Appropriateness of hospital utilization. The validity and reliability of the Intensity-Severity-Discharge Review System in a United Kingdom acute hospital setting.

Assessing the appropriateness of hospital utilization in the United Kingdom may yield practical solutions to problems faced by both purchasers and providers of health care in the National Health Service. It is, however, essential that such assessment is based on a method that is both valid and reliable--in particular, valid in the context in which it is applied. Whereas American methods for the assessment of appropriateness have been shown to be valid in the United States, it is pertinent to question whether the application of such methods to the National Health Service also is valid given the different circumstances, both cultural and financial, under which health care is provided. A study of the appropriateness of admission and hospital stay for a sample of admissions to a large acute hospital in the United Kingdom was carried out, and the assessment of appropriateness was made using the Intensity-Severity-Discharge Review System with Adult criteria (ISD-A). The validity and reliability of using the ISD-A for assessing hospital utilization in the United Kingdom was evaluated. The ISD-A was found to have high reliability and to be valid for assessing appropriateness in the United Kingdom when a full range of alternative forms of care are presumed to be available. It was not found to be valid currently, therefore, for routine assessment of hospital utilization within the National Health Service, when alternatives often are not available.