Adverse events were measured by nurses’ reports
of the frequency of occurrence of 4 types of
negative patient incidents on their shifts over the
past year: falls, nosocomial infections, medication
errors, and patient complaints. Nurses were asked
‘‘Over the past year, how often would you say each
of the following incidents has occurred involving
you or your patients.’’ Response options ranged
from 1 (never) to 4 (frequently).