G. Support, This study was supported by grants from the French Agency for Healthcare Research and Quality, 2006.

M. Bru, Véronique Buhaj (Périgueux General Hospital) Gilbert Destree (Compiègne General Hospital) Pierre Dujols (Montpellier University Hospital), Marie-Josée D'Alche-Gautier (Caen University Hospital) Eric Eynard (Orléans General Hospital) Véronique Fontaine (Saint-Philibert Hospital, Lomme), Sandrine Mercier (Chambéry General Hospital), Gilles Madelon (Montbéliard General Hospital) Laurent Pignard (Saint-Lo General Hospital) Jérôme Fauconnier (Grenoble University Hospital), and Bruno Aublet-Cuvelier

A. Cohen, G. Agnelli, F. Anderson, J. Arcelus, D. Bergqvist et al., Venous thromboembolism in Europe. The number of VTE events and associated morbidity and mortality, Thrombosis and Haemostasis, vol.98, pp.756-64, 2007.
DOI : 10.1160/TH07-03-0212

URL : https://hal.archives-ouvertes.fr/hal-00688301

F. Spencer, C. Emery, D. Lessard, F. Anderson, S. Emani et al., The worcester venous thromboembolism study, Journal of General Internal Medicine, vol.160, issue.7, pp.722-729, 2006.
DOI : 10.1111/j.1525-1497.2006.00458.x

C. Francis, Prophylaxis for Thromboembolism in Hospitalized Medical Patients, New England Journal of Medicine, vol.356, issue.14, pp.1438-1482, 2007.
DOI : 10.1056/NEJMcp067264

V. Tapson, Acute Pulmonary Embolism, New England Journal of Medicine, vol.358, issue.10, pp.1037-52, 2008.
DOI : 10.1056/NEJMra072753

URL : http://eurheartj.oxfordjournals.org/cgi/content/short/17/suppl_3/244

D. Coster, C. Quan, H. Finlayson, A. Gao, M. Halfon et al., Identifying priorities in methodological research using ICD-9-CM and ICD-10 administrative data: report from an international consortium, BMC Health Services Research, vol.57, issue.1, pp.77-83, 2006.
DOI : 10.1016/j.jclinepi.2004.03.012

F. Boulay, F. Berthier, G. Schoukroun, C. Raybaut, Y. Gendreike et al., Seasonal variations in hospital admission for deep vein thrombosis and pulmonary embolism: analysis of discharge data, BMJ, vol.323, issue.7313, pp.601-603, 2001.
DOI : 10.1136/bmj.323.7313.601

H. Sorensen, E. Horvath-puho, L. Pedersen, J. Baron, and P. Prandoni, Venous thromboembolism and subsequent hospitalisation due to acute arterial cardiovascular events: A 20-year cohort study, Journal of Vascular Surgery, vol.47, issue.5, pp.1773-1782, 2007.
DOI : 10.1016/j.jvs.2008.03.024

D. Aujesky, R. Stone, S. Kim, E. Crick, and M. Fine, Length of Hospital Stay and Postdischarge Mortality in Patients With Pulmonary Embolism<subtitle>A Statewide Perspective</subtitle>, Archives of Internal Medicine, vol.168, issue.7, pp.706-718, 2008.
DOI : 10.1001/archinte.168.7.706

L. Iezzoni, J. Daley, T. Heeren, S. Foley, E. Fisher et al., Identifying Complications of Care Using Administrative Data, Medical Care, vol.32, issue.7, pp.700-715, 1994.
DOI : 10.1097/00005650-199407000-00004

C. Zhan and M. Miller, Administrative data based patient safety research: a critical review, Quality and Safety in Health Care, vol.12, issue.90002, pp.58-63, 2003.
DOI : 10.1136/qhc.12.suppl_2.ii58

L. Iezzoni, Assessing Quality Using Administrative Data, Annals of Internal Medicine, vol.127, issue.8_Part_2, pp.666-74, 1997.
DOI : 10.7326/0003-4819-127-8_Part_2-199710151-00048

A. Tricco, B. Pham, and N. Rawson, Manitoba and Saskatchewan administrative health care utilization databases are used differently to answer epidemiologic research questions, Journal of Clinical Epidemiology, vol.61, issue.2, pp.192-197, 2008.
DOI : 10.1016/j.jclinepi.2007.03.009

R. White, L. Brickner, and K. Scannell, ICD-9-CM codes poorly indentified venous thromboembolism during pregnancy, Journal of Clinical Epidemiology, vol.57, issue.9, pp.985-993, 2004.
DOI : 10.1016/j.jclinepi.2004.02.003

C. Zhan, J. Battles, Y. Chiang, and D. Hunt, The Validity of ICD-9-CM Codes in Identifying Postoperative Deep Vein Thrombosis and Pulmonary Embolism, The Joint Commission Journal on Quality and Patient Safety, vol.33, issue.6, pp.326-357, 2007.
DOI : 10.1016/S1553-7250(07)33037-7

T. Larsen, S. Johnsen, C. Moller, H. Larsen, and H. Sorensen, A review of medical records and discharge summary data found moderate to high predictive values of discharge diagnoses of venous thromboembolism during pregnancy and postpartum, Journal of Clinical Epidemiology, vol.58, issue.3, pp.316-325, 2005.
DOI : 10.1016/j.jclinepi.2004.07.004

M. Severinsen, S. Kristensen, K. Overvad, C. Dethlefsen, A. Tjonneland et al., Venous thromboembolism discharge diagnoses in the Danish National Patient Registry should be used with caution, Journal of Clinical Epidemiology, vol.63, issue.2, p.10, 2009.
DOI : 10.1016/j.jclinepi.2009.03.018

L. Iezzoni, Risk adjustment for measuring health care outcomes, 2003.

H. Quan, G. Parsons, and W. Ghali, Validity of Information on Comorbidity Derived From ICD-9-CCM Administrative Data, Medical Care, vol.40, issue.8, pp.675-85, 2002.
DOI : 10.1097/00005650-200208000-00007

M. Sevestre, J. Labarere, P. Casez, L. Bressollette, M. Haddouche et al., Outcomes for inpatients with normal findings on whole-leg ultrasonography. A multicenter prospective cohort study
URL : https://hal.archives-ouvertes.fr/hal-00453692

M. Sevestre, J. Labarere, P. Casez, L. Bressollette, M. Taiar et al., Accuracy of complete compression ultrasound in ruling out suspected deep venous thrombosis in the ambulatory setting. A prospective cohort study, Thrombosis and Haemostasis, vol.102, pp.166-72, 2009.
DOI : 10.1160/TH09-01-0048

URL : https://hal.archives-ouvertes.fr/hal-00453681

S. Chunilal, J. Eikelboom, J. Attia, M. Miniati, A. Panju et al., Does This Patient Have Pulmonary Embolism?, JAMA, vol.290, issue.21, pp.2849-58, 2003.
DOI : 10.1001/jama.290.21.2849

P. Fedullo and V. Tapson, The Evaluation of Suspected Pulmonary Embolism, New England Journal of Medicine, vol.349, issue.13, pp.1247-56, 2003.
DOI : 10.1056/NEJMcp035442

P. Roy, G. Meyer, B. Vielle, L. Gall, C. Verschuren et al., Appropriateness of Diagnostic Management and Outcomes of Suspected Pulmonary Embolism, Annals of Internal Medicine, vol.144, issue.3, pp.157-64, 2006.
DOI : 10.7326/0003-4819-144-3-200602070-00003

H. Sorensen, L. Pedersen, L. Mellemkjaer, S. Johnsen, M. Skriver et al., The risk of a second cancer after hospitalisation for venous thromboembolism, British Journal of Cancer, vol.18, issue.7, pp.838-879, 2005.
DOI : 10.1001/jama.245.8.831

N. Patkar, J. Curtis, G. Teng, J. Allison, M. Saag et al., Administrative codes combined with medical records based criteria accurately identified bacterial infections among rheumatoid arthritis patients, Journal of Clinical Epidemiology, vol.62, issue.3, pp.321-328, 2009.
DOI : 10.1016/j.jclinepi.2008.06.006

J. Carpenter and J. Bithell, Bootstrap confidence intervals: when, which, what? A practical guide for medical statisticians, Statistics in Medicine, vol.35, issue.9, pp.1141-64, 2000.
DOI : 10.1002/(SICI)1097-0258(20000515)19:9<1141::AID-SIM479>3.0.CO;2-F

C. Ahn, Statistical methods for the estimation of sensitivity and specificity of site-specific diagnostic tests, Journal of Periodontal Research, vol.56, issue.4, pp.351-355, 1997.
DOI : 10.2307/2336267

A. Donner and N. Klar, Design and Analysis of Cluster Randomization Trials in Health Research London, 2000.

C. Zhan, A. Elixhauser, B. Friedman, R. Houchens, Y. Chiang et al., Modifying DRG-PPS to Include Only Diagnoses Present on Admission, Medical Care, vol.45, issue.4, pp.288-91, 2007.
DOI : 10.1097/01.mlr.0000256969.34461.cf

W. Best, S. Khuri, M. Phelan, K. Hur, W. Henderson et al., Identifying patient preoperative risk factors and postoperative adverse events in administrative databases: results from the department of veterans affairs national surgical quality improvement program 1 1No competing interests declared., Journal of the American College of Surgeons, vol.194, issue.3, pp.257-66, 2002.
DOI : 10.1016/S1072-7515(01)01183-8

K. Henderson, A. Recktenwald, R. Reichley, T. Bailey, B. Waterman et al., Clinical Validation of the AHRQ Postoperative Venous Thromboembolism Patient Safety Indicator, The Joint Commission Journal on Quality and Patient Safety, vol.35, issue.7, pp.370-376, 2009.
DOI : 10.1016/S1553-7250(09)35052-7

E. Haut, K. Noll, D. Efron, S. Berenholz, A. Haider et al., Can Increased Incidence of Deep Vein Thrombosis (DVT) be Used as a Marker of Quality of Care in the Absence of Standardized Screening? The Potential Effect of Surveillance Bias on Reported DVT Rates after Trauma, The Journal of Trauma: Injury, Infection, and Critical Care, vol.63, issue.5, pp.1132-1137, 2007.
DOI : 10.1097/TA.0b013e31814856ad

P. Pronovost, C. Goeschel, and R. Wachter, The Wisdom and Justice of Not Paying for ???Preventable Complications???, JAMA, vol.299, issue.18, pp.2197-2206, 2008.
DOI : 10.1001/jama.299.18.2197

E. Birman-deych, A. Waterman, Y. Yan, D. Nilasena, M. Radford et al., Accuracy of ICD-9-CM Codes for Identifying Cardiovascular and Stroke Risk Factors, Medical Care, vol.43, issue.5, pp.480-485, 2005.
DOI : 10.1097/01.mlr.0000160417.39497.a9

S. Heckbert, C. Kooperberg, M. Safford, B. Psaty, J. Hsia et al., Comparison of Self-Report, Hospital Discharge Codes, and Adjudication of Cardiovascular Events in the Women's Health Initiative, American Journal of Epidemiology, vol.160, issue.12, pp.1152-1160, 2004.
DOI : 10.1093/aje/kwh314

T. Henderson, J. Shepheard, and V. Sundararajan, Quality of Diagnosis and Procedure Coding in ICD-10 Administrative Data, Medical Care, vol.44, issue.11, pp.1011-1020, 2006.
DOI : 10.1097/01.mlr.0000228018.48783.34

L. So, D. Evans, and H. Quan, ICD-10 coding algorithms for defining comorbidities of acute myocardial infarction, BMC Health Services Research, vol.6, issue.20, p.161, 2006.
DOI : 10.1186/1472-6963-6-48

S. Schneeweiss and J. Avorn, A review of uses of health care utilization databases for epidemiologic research on therapeutics, Journal of Clinical Epidemiology, vol.58, issue.4, pp.323-360, 2005.
DOI : 10.1016/j.jclinepi.2004.10.012