title: Pretest probability of a normal echocardiography: validation of a simple and practical algorithm for routine use.
abstract: BACKGROUND
  Management of increased referrals for transthoracic echocardiography (TTE) examinations is a challenge. Patients with normal TTE examinations take less time to explore than those with heart abnormalities. A reliable method for assessing pretest probability of a normal TTE may optimize management of requests.
  
  
  OBJECTIVE
  To establish and validate, based on requests for examinations, a simple algorithm for defining pretest probability of a normal TTE.
  
  
  METHODS
  In a retrospective phase, factors associated with normality were investigated and an algorithm was designed. In a prospective phase, patients were classified in accordance with the algorithm as being at high or low probability of having a normal TTE.
  
  
  RESULTS
  In the retrospective phase, 42% of 618 examinations were normal. In multivariable analysis, age and absence of cardiac history were associated to normality. Low pretest probability of normal TTE was defined by known cardiac history or, in case of doubt about cardiac history, by age>70 years. In the prospective phase, the prevalences of normality were 72% and 25% in high (n=167) and low (n=241) pretest probability of normality groups, respectively. The mean duration of normal examinations was significantly shorter than abnormal examinations (13.8 ± 9.2 min vs 17.6 ± 11.1 min; P=0.0003).
  
  
  CONCLUSIONS
  A simple algorithm can classify patients referred for TTE as being at high or low pretest probability of having a normal examination. This algorithm might help to optimize management of requests in routine practice.
authors.affiliation: Department of Cardiology, Pitié-Salpêtrière Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France; Faculté de Médecine Pierre et Marie Curie, university Paris 6, Paris, France; Institute of Cardiometabolism and Nutrition (ICAN), Paris, France. Electronic address: nadjib.hammoudi@psl.aphp.fr.
authors.forename: Nadjib
authors.initials: N
authors.lastname: Hammoudi
authors.affiliation: Department of Cardiology, Pitié-Salpêtrière Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France.
authors.forename: Matthieu
authors.initials: M
authors.lastname: Duprey
authors.affiliation: Department of Cardiology, Pitié-Salpêtrière Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Régnier
authors.affiliation: Department of Cardiology, Pitié-Salpêtrière Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Achkar
authors.affiliation: Department of Cardiology, Pitié-Salpêtrière Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France; Faculté de Médecine Pierre et Marie Curie, university Paris 6, Paris, France.
authors.forename: Lila
authors.initials: L
authors.lastname: Boubrit
authors.affiliation: Department of Cardiology, Pitié-Salpêtrière Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France.
authors.forename: Gisèle
authors.initials: G
authors.lastname: Preud'homme
authors.affiliation: Department of Cardiology, Pitié-Salpêtrière Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France; Faculté de Médecine Pierre et Marie Curie, university Paris 6, Paris, France.
authors.forename: Aude
authors.initials: A
authors.lastname: Healy-Brucker
authors.affiliation: Department of Cardiology, Pitié-Salpêtrière Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France; Faculté de Médecine Pierre et Marie Curie, university Paris 6, Paris, France.
authors.forename: Jean-Baptiste
authors.initials: JB
authors.lastname: Vignalou
authors.affiliation: Department of Cardiology, Pitié-Salpêtrière Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France; Institute of Cardiometabolism and Nutrition (ICAN), Paris, France.
authors.forename: Françoise
authors.initials: F
authors.lastname: Pousset
authors.affiliation: Department of Cardiology, Pitié-Salpêtrière Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France; Faculté de Médecine Pierre et Marie Curie, university Paris 6, Paris, France; Institute of Cardiometabolism and Nutrition (ICAN), Paris, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Komajda
authors.affiliation: Department of Cardiology, Pitié-Salpêtrière Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France; Faculté de Médecine Pierre et Marie Curie, university Paris 6, Paris, France; Institute of Cardiometabolism and Nutrition (ICAN), Paris, France.
authors.forename: Richard
authors.initials: R
authors.lastname: Isnard
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D016009:Chi-Square Distribution; D003661:Decision Support Techniques; D004452:Echocardiography; D005260:Female; D006331:Heart Diseases / Q000000981:diagnostic imaging* / Q000209:etiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D018579:Patient Selection; D011237:Predictive Value of Tests; D011336:Probability; D011446:Prospective Studies; D012017:Referral and Consultation; D015203:Reproducibility of Results; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors
keywords: Algorithm; Algorithme; ETT; Echocardiographie trans-thoraciques; Probability; Probabilité; Pré-test; Screening; TTE; Transthoracic echocardiography