Guidelines aim to assist physicians about appropriate health care for specific clinical circumstances. Therefore, they must be continuously updated, integrated and tailored to local situations.We applied recently developed guidelines for autoantibody testing by assessing their economic (efficiency) and clinical (effectiveness) impact. Since June 2002, a test order algorithm has been adopted for autoantibody testing requests (3258). In particular, the guidelines were modified taking into account the needs of different departments and the results were compared to those (2762) of the previous period (January-May 2002) that had not been integrated with any diagnostic algorithm.A significant reduction in the number of anti-double stranded DNA (anti-dsDNA) (21.4%) and anti-Extractable Nuclear Antigens (anti-ENA) (19%) was found (p0.0001), while the number of anti-nuclear antibody (ANA) test was unchanged (p=n.s.); further reduction in clinically inappropriate test request rates (23%) was observed.The application of guidelines allowed the improvement of diagnostic tests' efficiency and clinical effectiveness (patient's outcomes), thus confirming the need to apply eventual modifications to the diagnostic process taking into consideration different clinical needs.
