title: Risk factors for prescribing and transcribing medication errors among elderly patients during acute hospitalization: a cohort, case-control study.
abstract: BACKGROUND
  Medication errors are the cause of common and dangerous adverse effects on patients. They occur as a result of preventable failures in the prescribing (ordering), transcribing, dispensing and administration of medications.
  
  
  OBJECTIVE
  The aim of this study was to determine the relationship between patient characteristics and prescribing and transcribing medication errors during acute hospitalization of elderly patients in an internal medicine ward.
  
  
  METHODS
  A cohort case-control study was conducted in a 37-bed medical ward at a tertiary medical centre in Israel. The study included 137 patients in whom potentially harmful medication errors were detected, and 137 sex- and age-matched controls. Clinical data were collected and Charlson Comorbidity Index scores were calculated. Conditional logistic regression was used to identify factors associated with medication errors.
  
  
  RESULTS
  Independent factors associated with any type of medication error included Charlson Comorbidity Index score ≥8 (odds ratio [OR] 2.97 [95% CI 1.16, 7.61], p  =  0.023), number of medications ≥ 9 (OR 2.02 [95% CI 1.00, 4.05], p  =  0.049) [both upon admission] and length of hospital stay ≥ 13 days (OR 4.41 [95% CI 2.25, 8.62], p  <  0.0001). Independent factors associated with prescribing errors included Charlson Comorbidity Index score ≥ 8 (OR 6.34 [95% CI 1.63, 24.71], p  =  0.008) and length of hospital stay ≥13 days (OR 3.19 [95% CI 1.23, 8.26], p  =  0.017), while independent factors associated with transcribing errors included number of medications ≥9 (OR 2.58 [95% CI 1.02, 6.51], p  =  0.04) and length of hospital stay ≥ 13 days (OR 6.90 [95% CI 2.76, 17.23], p  <  0.0001). The median time to an error was 3 days, and was half as long for prescribing errors as for transcribing errors (2 and 4 days, respectively, p = 0.017).
  
  
  CONCLUSIONS
  The risk of medication errors among elderly patients during acute hospitalization in an internal medicine ward is associated with Charlson Comorbidity Index score (for prescribing errors), number of medications (for transcribing errors) and length of hospital stay (for both types of errors). Further study will determine whether these factors can be used to identify patients at risk and to prevent prescribing and transcribing medication errors.
authors.affiliation: Department of Medicine C, Hadassah-Hebrew University Medical Center, Jerusalem, Israel.
authors.forename: Arie
authors.initials: A
authors.lastname: Ben-Yehuda
authors.forename: Yitzchak
authors.initials: Y
authors.lastname: Bitton
authors.forename: Pnina
authors.initials: P
authors.lastname: Sharon
authors.forename: Elena
authors.initials: E
authors.lastname: Rotfeld
authors.forename: Tikva
authors.initials: T
authors.lastname: Armon
authors.forename: Mordechai
authors.initials: M
authors.lastname: Muszkat
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D016022:Case-Control Studies; D015331:Cohort Studies; D011307:Drug Prescriptions / Q000706:statistics & numerical data*; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D007388:Internal Medicine / Q000706:statistics & numerical data; D053208:Kaplan-Meier Estimate; D008297:Male; D008505:Medical Staff, Hospital / Q000706:statistics & numerical data; D008508:Medication Errors / Q000706:statistics & numerical data*; D012044:Regression Analysis; D012307:Risk Factors