K. Barnett, S. Mercer, M. Norbury, G. Watt, S. Wyke et al., Epidemiology of multimorbidity and implications for health care, research, and medical education: a cross-sectional study, The Lancet, vol.380, issue.9836, pp.37-43, 2012.
DOI : 10.1016/S0140-6736(12)60240-2

P. Limpawattana, P. Phungoen, T. Mitsungnern, W. Laosuangkoon, and N. Tansangworn, Atypical presentations of older adults at the emergency department and associated factors, Archives of Gerontology and Geriatrics, vol.62, issue.5, pp.300-348, 2015.
DOI : 10.1016/j.archger.2015.08.016

O. Rutschmann, T. Chevalley, C. Zumwald, C. Luthy, B. Vermeulen et al., Pitfalls in the emergency department triage of frail elderly patients without specific complaints, Swiss Med Wkly, vol.135, pp.9-10145, 2005.

N. Hodgson, L. Gitlin, L. Winter, and K. Czekanski, Undiagnosed Illness and Neuropsychiatric Behaviors in Community Residing Older Adults With Dementia, Alzheimer Disease & Associated Disorders, vol.25, issue.2, pp.109-124, 2011.
DOI : 10.1097/WAD.0b013e3181f8520a

W. Self, D. Courtney, C. Mcnaughton, R. Wunderink, and J. Kline, High discordance of chest x-ray and computed tomography for detection of pulmonary opacities in ED patients: implications for diagnosing pneumonia, The American Journal of Emergency Medicine, vol.31, issue.2, pp.401-406, 2013.
DOI : 10.1016/j.ajem.2012.08.041

L. Nguyen, D. Wong, D. Fatovich, J. Yeung, J. Persaud et al., Low-dose computed tomography versus plain abdominal radiography in the investigation of an acute abdomen, ANZ Journal of Surgery, vol.62, issue.1-2, pp.36-41, 2012.
DOI : 10.1111/j.1445-2197.2010.05632.x

L. Ebner, Y. Bütikofer, D. Ott, A. Huber, J. Landau et al., Lung Nodule Detection by Microdose CT Versus Chest Radiography (Standard and Dual-Energy Subtracted), American Journal of Roentgenology, vol.204, issue.4, pp.727-762, 2015.
DOI : 10.2214/AJR.14.12921

T. Blanchon, J. Bréchot, P. Grenier, G. Ferretti, E. Lemarié et al., Baseline results of the Depiscan study: A French randomized pilot trial of lung cancer screening comparing low dose CT scan (LDCT) and chest X-ray (CXR), Lung Cancer, vol.58, issue.1, pp.50-58, 2007.
DOI : 10.1016/j.lungcan.2007.05.009

URL : https://hal.archives-ouvertes.fr/inserm-00173095

A. Van-randen, W. Laméris, H. Van-es, H. Van-heesewijk, B. Van-ramshorst et al., A comparison of the Accuracy of Ultrasound and Computed Tomography in common diagnoses causing acute abdominal pain, European Radiology, vol.28, issue.Suppl, pp.1535-1580, 2011.
DOI : 10.1007/s00330-011-2087-5

H. Rotert, G. Nöldge, J. Encke, G. Richter, and M. Düx, Der Stellenwert der CT in der Akutdiagnostik der Divertikulitis, Der Radiologe, vol.43, issue.1, pp.51-59, 2003.
DOI : 10.1007/s00117-002-0849-4

N. Faucher, T. Cudennec, L. Mouël, L. Roger, and M. , Constipation et impaction fécale : des maux fréquents en gériatrie, Rev Geriatr, vol.29, issue.6, pp.435-476, 2004.

S. Matthews and J. Lancaster, Urinary Tract Infections in the Elderly Population, The American Journal of Geriatric Pharmacotherapy, vol.9, issue.5, pp.286-309, 2011.
DOI : 10.1016/j.amjopharm.2011.07.002

C. Pérez-guzman and M. Vargas, Mycobacterial Infections in the Elderly, Seminars in Respiratory and Critical Care Medicine, vol.31, issue.05, pp.575-86, 2010.
DOI : 10.1055/s-0030-1265898

Y. Ghanem, M. Paul, and L. Leibovici, Presentation of infection in older patients-a prospective study, Ann Med, vol.47, issue.4, pp.354-362, 2015.

A. Wester, O. Dunlop, K. Melby, U. Dahle, and T. Wyller, Agerelated differences in symptoms, diagnosis and prognosis of bacteremia, BMC Infect Dis, vol.2413, p.346, 2013.

S. Law and K. Li, Older age as a poor prognostic sign in patients with pyogenic liver abscess, International Journal of Infectious Diseases, vol.17, issue.3, pp.177-84, 2013.
DOI : 10.1016/j.ijid.2012.09.016

Q. Qian, C. Jiang, Y. Chen, Z. Ding, Y. Wu et al., A modified total colonic exclusion for elderly patients with severe slow transit constipation, Techniques in Coloproctology, vol.57, issue.7, pp.629-663, 2014.
DOI : 10.1007/s10151-013-1108-6