The role of quality standards--accreditation in redressing asymmetry of information in health care markets.

Asymmetry of information presents major difficulties for the efficient operation of markets in health care. The use of accreditation schemes may reduce these difficulties by enhancing the availability of reliable, accessible information on aspects of service quality considered important by service users and their agents. The UK's Patients' Charter with its associated Charter Marks has the potential to perform such a function in respect of inpatient services. In as much as it refers to aspects of service valued by service users which are specified in contracts by service procurers and appear not to be negatively correlated with other aspects of service quality, it can be seen to provide unambiguous signals of service quality. Given the Charter is currently under review, it seems appropriate that such attributes are borne in mind by policy makers in their deliberations as to its future.