Total care usage of a defined population.

The North Staffordshire (Stoke) Morbidity Survey was set up to bring together data about the total use of general practice, hospital and local authority services by each individual patient in a representative sample of the population of Stoke, and to examine the associated problems of data linkage and confidentiality. Approximately 47.8 per cent (32.1 per cent if allowance is made for all measurable possible errors) of the patients attending hospital and 43.8 per cent of patients attending local authority services during the year, did not attend their general practitioner.Primary automation of the registered list of patients at risk is essential to the success of any automated linkage study. Where the list consists of Hogben numbers to identify individuals, this also ensures the necessary confidentiality of sensitive data.