Impact of hip fracture on hospital care costs : a population-based study - Leal, José (University of Oxford. Nuffield Department of Population Health) ; Gray, A. M. (University of Oxford. Nuffield Department of Population Health) ; Prieto-Alhambra, Daniel (Institut Hospital del Mar d'Investigacions Mèdiques) ; Arden, N. K. (University Hospital Southampton NHS Foundation Trust (Regne Unit)) ; Cooper, Cyrus (University Hospital Southampton NHS Foundation Trust (Regne Unit)) ; Javaid, M. K. (University Hospital Southampton NHS Foundation Trust (Regne Unit)) ; Judge, Andrew (University Hospital Southampton NHS Foundation Trust (Regne Unit)) ; Universitat Autònoma de Barcelona