A direct method for the identification of patterns of care using administrative databases: the case of breast cancer

OBJECTIVES: To identify and provide lists of procedures and drugs related to diagnosis and treatment of breast cancer. These lists can be used for the estimation of the cost of illness. METHODS: The method consists of identifying lists of procedures/interventions/drugs related to the tumour of interest, drawn by a panel of expert clinicians and oncologists on the basis of clinical guidelines and current practice. The lists are applied to data referring to breast cancer female patients, collected by population-based Cancer Registries and linked at individual level with information on health care treatments. A comparison with lists obtained via the matched control method is implemented. RESULTS: The distribution of administered procedures and drug prescriptions is coherent with the patient clinical pathway: surgery is the main cause of hospitalization in the first year since diagnosis, diagnostic and monitoring interventions are more frequent in the following years (recurrences detection), and at end-of-life (palliative care). Most outpatient services are due to diagnosis and monitoring, one third of services in the first year since diagnosis is radiotherapy and chemotherapy. Drugs prescribed to patients and sold in pharmacy include hormonal drugs as first course treatment and analgesics as palliative care. CONCLUSIONS: This direct method represents a valid alternative to the matched control method in describing patterns of care and costs related to the entire disease pathway. It is particularly suitable in case of cancer sites with complex patterns of care, such as breast cancer. The lists of codes developed here are based on international classification systems and can be easily applicable to other countries. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10198-021-01327-8.