OBJECTIVES: To explore the potential of online patient networks (PN) as a viable source of PRO data for clinical research. Several PNs have emerged in the last few years in different European countries, and as a natural meeting point for chronic patients with an active engaged with their communities, they represent a promising source of patient reported data. In this original, the experience with the French PN “Carenity” is described.   METHODS: Given the great heterogeneity of the users of “Carenity”, and the fact that the test was computer-led by definition, a Computer Adaptive Test (CAT) was considered the best choice. The authors decided to use a culturally adapted version of CAT-Health system, which measures generic health-related quality of life (HRQoL). However, in absence of a calibration for the French population, a selection of the best items was used, using the Spanish calibration as a reference. All patients in the PN were invited to participate in the test. A score was estimated for the test using the Spanish parameters, as a rough approximation of the real score. Age, sex and the main pathology of the subjects were also collected. RESULTS: Preliminary results from the first week of data collection show 601 patients answered (Women: 404, Men: 140). The most frequent reported pathologies and their t-scores were multiple sclerosis (N:92,M:37.91,SD:5.85), fibromyalgia (N:81,M:36.65,SD:4.99), ankylosing spondylitis(N:60,M:37.74,SD:5.32) and both types of diabetes (I: N:53,M:50.38,SD:10.94, II: N:41,M:48.12,SD:10.04). Significant differences (p<0.05) were found in diabetes patients by sex, and between both types of diabetes and the other 3 most common pathologies.  CONCLUSIONS: Carenity PN seems to be a fast way to obtain PRO scores directly from patients. Preliminary results show differences in the expected direction.