[Analysis of the medical activity related to cancer in a network of multidisciplinary hospitals using claims databases, the reseau Concorde Oncology Network].

Recently, to answer patients, caregivers and professionals needs, the "Plan Cancer" has been presented by the French Government. This plan is intended to improve quality of care in cancer patients and finally, patients' survival and quality of life. This planned strategy stresses the importance of organized interactions between hospitals and between the various health professionals. Measuring the number of patients with cancer and the activity related to cancer in large networks of multidisciplinary hospitals has became a real challenge in France for organizational, quality of care and economic reasons. Many University Hospitals in France have chosen to face this question by using the French DRG based information system called PMSI. It allows estimating the proportion of hospital stays concerned by cancers that are identified with algorithms based on ICD 10. However, French databases of hospital discharges do not allow patients identification. We collected data on hospital stays and patients in a subset of an organized network focused on cancer care and composed of 55 public or private hospitals in the Rhone-Alpes area. We used these data to estimate the number of patients who had been hospitalized within the network in 2000. Approximately 110,000 hospital stays were related with a diagnostic of cancer, corresponding to a number of patients within a range of 30345 to 35700. In absence of communicating files between hospitals, claims databases are an interesting source of information for cancer burden. The recent implementation of a procedure allowing the linkage of data concerning each patient should permit better estimates in the future. The main limitation will remain the possibility of a hospital to participate to more than one network.