This study analyzes the evolution of the collaborative network between the hospitals of the Abruzzo region between 2009 and 2011 using the Social Network Analysis theories and methods. The analysis shows that hospitals collaborate using an inherent memory consisting of the previous relations and of endogenous self-organizing mechanisms. Also the LHA membership, the number of staffed beds, the geographical distance from other hospitals, the percentage of admitted in emergency and the percentage of inappropriate hospital admissions affect the propensity of hospitals to cooperate. The implications for managers and policy makers are discussed.
Keywords: Inter-hospital collaboration, longitudinal analysis, Abruzzo