title: Laboratory Tests Ordering Pattern by Medical Residents From a Brazilian University Hospital.
abstract: OBJECTIVE
  The adequacy of laboratory test orders by medical residents is a longstanding issue. The aim of this study is to analyze the number, types, and pattern of repetition of tests ordered by medical residents.
  
  
  METHODS
  We studied all tests ordered over a 1-year period for inpatients of an internal medicine ward in a university hospital. Types, results, and repetition pattern of tests were analyzed in relation to patients' diagnoses.
  
  
  RESULTS
  We evaluated 117,666 tests, requested for 1,024 inpatients. The mean number of tests was 9.5 per day. The test repetition pattern was similar, regardless of patients' diagnoses, previous test results, or duration of stay. The probability of an abnormal result after a sequence of three normal tests was lower than 25%, regardless of the diagnosis.
  
  
  CONCLUSIONS
  Number of tests and repetition were both high, imposing costs, discomfort, and risks to patients, thus warranting further investigation.
authors.affiliation: From the Division of Clinical Pathology, Department of Pathology, mirtes@usp.br.
authors.forename: Maria M
authors.initials: MM
authors.lastname: Sales
authors.affiliation: Discipline of Emergency Medicine.
authors.forename: Leandro U
authors.initials: LU
authors.lastname: Taniguchi
authors.affiliation: Department of Internal Medicine, Clinical Immunology and Allergy Service.
authors.forename: Luiz A M
authors.initials: LA
authors.lastname: Fonseca
authors.affiliation: Department of Internal Medicine, General Practice and Propedeutic Service, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Mario
authors.initials: M
authors.lastname: Ferreira-Junior
authors.affiliation: Discipline of Emergency Medicine.
authors.forename: Francisco J B
authors.initials: FJ
authors.lastname: Aguiar
authors.affiliation: From the Division of Clinical Pathology, Department of Pathology.
authors.forename: Nairo M
authors.initials: NM
authors.lastname: Sumita
authors.affiliation: Department of Internal Medicine, General Practice and Propedeutic Service, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Arnaldo
authors.initials: A
authors.lastname: Lichtenstein
authors.affiliation: From the Division of Clinical Pathology, Department of Pathology.
authors.forename: Alberto J S
authors.initials: AJ
authors.lastname: Duarte
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001938:Brazil; D003955:Diagnostic Tests, Routine / Q000191:economics*; D005260:Female; D006785:Hospitals, University / Q000191:economics*; D006801:Humans; D007396:Internship and Residency; D007755:Laboratories, Hospital / Q000191:economics*; D008297:Male; D008875:Middle Aged; D010818:Practice Patterns, Physicians' / Q000191:economics*; D055815:Young Adult
keywords: Laboratory tests; Medical residents; Redundant diagnostic tests; Retesting; Test utilization