NHS QIS considers possible differences in the application of appraisals for Scotland based on four criteria: Principles and values of NHSScotlandEpidemiology (frequency, distribution and stage at presentation)Structure and provision of services in ScotlandOther implications for NHSScotland, including rural issues, predicted uptake or existing advice from the Scottish Medicines Consortium.NHS QIS involves a small number of experts in this process, and this has allowed it to make decisions about the validity of NICE appraisals for Scotland prior to the publication of the appraisal by NICE.