A reconstruction of a medical history from administrative data: with an application to the cost of skin cancer

The medical record is a repository of clinical data, which can greatly enhance the quality of health and healthcare analysis. Administrative data are collected for the purpose of billing and reimbursement, and are valued by health researchers because the data are routinely audited to maintain accurate financial records. However, the quantity of incorporated clinical data can be variable. In this paper we reconstruct the medical record from health service invoices to estimate the cost of treating keratinocytic cancer (KC). The data from an epidemiological survey were linked to an administrative data set supplied by the national health insurer. A matched sampling technique with multivariable analysis was used to estimate cost. A KC treatment was identified with 42 service codes which explicitly nominated treatment of a KC. Algorithms identifying comorbities potentially correlated with KC were constructed from the service codes. The annual cost of a KC treatment was estimated to be AU$667 per individual. The average cost of explicit KC treatments was AU$231, while the cost of generic procedures used to treat KC was AU$436. Our ability to accurately control for the medical history enabled our analysis to quantify and describe the constituent costs of KC treatment.