Observer Bias in Hand Hygiene Compliance Reporting

Differences in reported hand hygiene compliance rates were assessed on the basis of the unit affiliation of observers. In 2 hospitals, unit-based observers more often reported higher compliance rates than did non-unit-based observers (79% vs 58.6%; difference, 20.4%; P<.001). Nonstandardized data collection methods contribute to the variability in hand hygiene compliance rates.