Nighttime and weekend medication error rates in an inpatient pediatric population

Nighttime and weekend admission has been associated with increased morbidity and mortality and has been linked to a variety of factors. Medication errors in hospitalized patients occur frequently, but the association between error rates and time of day and day of week (weekday vs weekend) has not been extensively studied.

To compare reported medication error rates over a 1-year period between daytime versus nighttime shifts and weekday versus weekend in a children's hospital and to characterize the types of errors that occurred.

One hundred forty errors reported between January and December 2008 were retrospectively reviewed and classified by error type and severity according to established standards. Two investigators independently classified errors, and a third investigator with pediatric pharmacy expertise resolved discrepancies. Data on doses dispensed were collected from pharmacy records.

Over the study period, the reported error rate during daytime nursing shifts was 1.17 errors per 1000 doses dispensed versus 2.12 errors per 1000 doses dispensed for nighttime nursing shifts (p = 0.005). The error rates during pharmacy shifts (1st, 2nd, and 3rd) were 1.01, 2.24, and 1.88 per 1000 doses dispensed, respectively (p = 0.0019). Reported errors for weekday versus weekend were 1.9 errors per 1000 weekday doses versus 2.55 errors per 1000 doses, respectively (p = 0.181), and error rate for weekend shifts relative to first shift on weekdays was greater (p = 0.0004). Errors in medication administration, followed by dispensing errors, occurred most frequently.

There was an increase in medication error rate during evening and nighttime shifts relative to day shift and during weekends relative to weekdays at this institution. Additional studies to validate this finding are needed; however, error prevention efforts should be instituted now for evening, nighttime, and weekend medication dispensing and administration.