title: Cohort study for evaluation of dose omission without justification in a teaching general hospital in Bahia, Brazil.
abstract: OBJECTIVE
  To evaluate the incidence of medication errors due to dose omissions and the reasons for non-administration of medications.
  
  
  METHODS
  A cohort study blinded to the nursing staff was conducted for 5 consecutive days to evaluate administration of prescribed medications to selected inpatients.
  
  
  METHODS
  A major academic teaching hospital in Brazil.
  
  
  METHODS
  Dispensed doses to patients in medical and surgical wards.
  
  
  METHODS
  Doses returned to pharmacy were evaluated to identify the rate of dose omission without a justification for omission.
  
  
  RESULTS
  Information was collected from 117 patients in 11 wards and 1119 doses of prescribed medications were monitored. Overall, 238/1119 (21%) dispensed doses were not administered to the patients. Among these 238 doses, 138 (58%) had no justification for not being administered. Failure in the administration of at least 1 dose occurred for 58/117 (49.6%) patients. Surgical wards had significantly more missed doses than that in medical wards (P = 0.048). The daily presence of a pharmacist in the wards was significantly correlated with lower frequency of omission errors (P = 0.019). Nervous system medications were missed more significantly than other medications (P < 0.001). No difference was noted in the omission doses in terms of route of administration.
  
  
  CONCLUSIONS
  High incidence of omission errors occurs in our institution. Factors such as the deficit of nursing staff and clinical pharmacists and a weak medication dispensing system, probably contributed to incidence detected. Blinding nursing staff was essential to improve the sensibility of the method for detecting omission errors.
authors.affiliation: Pharmacy Department, University Hospital Professor Edgard Santos, Bahia, Brazil.
authors.forename: Bartyra
authors.initials: B
authors.lastname: Leite
authors.affiliation: Multidisciplinary Institute of Health, Federal University of Bahia, Brazil.
authors.forename: Sostenes
authors.initials: S
authors.lastname: Mistro
authors.affiliation: Pharmacy Department, University Hospital Professor Edgard Santos, Bahia, Brazil.
authors.forename: Camile
authors.initials: C
authors.lastname: Carvalho
authors.affiliation: Department of Medicine, University of California, San Diego, CA, USA.
authors.forename: Sanjay R
authors.initials: SR
authors.lastname: Mehta
authors.affiliation: Department of Medicine and Diagnostic, Federal University of Bahia, Salvador, Brazil.
authors.forename: Roberto
authors.initials: R
authors.lastname: Badaro
mesh_terms: D001938:Brazil; D006769:Hospitals, General; D006784:Hospitals, Teaching / Q000706:statistics & numerical data*; D006801:Humans; D008508:Medication Errors / Q000451:nursing* / Q000706:statistics & numerical data*; D008510:Medication Systems, Hospital / Q000458:organization & administration / Q000706:statistics & numerical data*; D010595:Pharmacists / Q000706:statistics & numerical data*; D010607:Pharmacy Service, Hospital / Q000458:organization & administration; D016037:Single-Blind Method
keywords: dose omission; medication error; patient safety