 The second concern about the use of diuretics is the risk of low therapeutic compliance of hypertensive patients, due to the diuretic effect and other hypokalemia-related side-effects 26,27. These few reports, however, contrast with the evidence that quality of life is improved by long term therapy with diuretics 28-30. The effort, therefore, should probably be direct toward persistence of initial treatment with diuretics, a goal that might be reached by improving the procedures of follow-up, for instance, as we have recently proposed, by implementing internet-based digital networks, connecting hypertension specialists with general practitioners 31. The Campania Salute CSnetwork is a system that was set up in 1995 by us 31. It is an italian regional network system aimed at improving the management of essential hypertension by integrating the activity of general practitioners GPs with hypertension specialists. This network includes about 12.000 hypertensive patients followed by 23 outpatient hypertensive clinics allocated in different Community Hospitals in the Campania Region and 60 GPs, homogeneously allocated in the regional area, referring to the Hypertension Clinic of Federico II University Hospital in Naples coordinating centre. GPs were randomly selected among a pool of physicians referring their patients to the Hypertension Clinic at Federico II University. Through the CS system clinical data detected at each visit can be shared between the coordinating center and the peripheral units.Low-risk hypertensive patients continue their follow up in the peripheral units, whereas high-risk hypertensive patients are more closely followed up by the coordinating centre, which also evaluates target organ damage and associated diseases. Patients information is shared through on-line access to the remote database, integrated by smartcards. The smartcard belongs to patients and contains hisher personal identification number PIN. This PIN allows users to access the file of the patient stored in the database. Each physician has also his own PIN to access into the database, limited to hisher own patient files. Clinical data are upgraded at each visit by GPs and physicians of both peripheral centres and coordinator centre. Access to the remote database allows users to read all clinical and laboratory data, as well as tracking electrocardiography ECG and cardiac and vascular ultrasound images. In addition, the smartcard also works as portable database in which identification and clinical data are reported. By virtue of a central database, data of individual patients can be stored, updated and retrieved directly on-line by participants in the project. The restricted access to individual data requires the pre-assigned identification code of both the patient and the relevant remote units. The central database uses Wincare software TSD Projects, Milan, Italy which contains separate sheets for medical history, physical examination, biochemistry electrocardiography, cardiovascular ultrasound, other imaging tests and ambulatory blood pressure monitoring. The last update of an individual patients record can also be downloaded and stored in the patients personal smartcard. We started the CS project with the aim of obtaining a stronger interaction between GPs and hypertension clinics, by providing a direct link and accessible patients records. Blood pressure control was improved with our referral system, since better overall results were obtained if the patient was followed within the network. Indeed, at the end of the observation period, 51 of patients in the CS group had a blood pressure below 14090 mmHg, a percentage comparable to that of patients included in clinical trials. 