Loeb and McGeer CriteriaA PRACTICAL GUIDE FOR USE IN LONG-TERM CAREClinical and Surveillance Criteria—Why do we have both?

Clinical criteria are meant to inform decisions on individual patients when care is needed.
▪ When these criteria are used for clinical decision making (e.g., to start an antibiotic),
clinical information (e.g., diagnostic test results, condition duration) is often unknown.
▪ Clinical criteria take into account patient factors, like indwelling devices.
▪ Clinical criteria are important because we treat patients, not case definitions.
Surveillance criteria are used to count true case events (i.e., diagnosed infections) and to
estimate the actual incidence/prevalence of disease conditions.
▪ These criteria are applied retrospectively (after the fact), often with new information (e.g.,
diagnostic culture results, which can take days to receive) that was not available during
initial clinical assessment.
▪ Surveillance criteria are designed to increase the likelihood that all patients counted truly
have the infection of interest.
▪ Because infections in long-term care patients might not have typical symptoms, failure to
meet surveillance definitions does not always mean there was no infection present.
Loeb Criteria are Designed for Clinical Use
Loeb criteria are meant to be a minimum set of signs and symptoms which, when met, indicate
that the resident likely has an infection and that an antibiotic might be indicated, even if the
infection has not been confirmed by diagnostic testing.
▪ When criteria are met, there is reasonable expectation that the resident has an infection.
▪ Clinical criteria err on the side of caution, leading to treatment of some likely infections,
not just confirmed infections. For this reason, these criteria are not used for retrospectively
counting true infections.
Because they summarize information available to prescribers when making initial treatment
decisions, Loeb criteria can be used retrospectively to assess antibiotic initiation and selection
appropriateness.
LOEB AND MCGEER CRITERIA: A PRACTICA L GUIDE FOR USE IN L ONG – TERM CARE
2
McGeer and NHSN Criteria are Designed for Surveillance
Revised McGeer criteria (Stone 2012) are used for retrospectively counting true infections.
▪ To meet the criteria for definitive infection, more diagnostic information (e.g., positive
laboratory tests) is often necessary.
▪ Surveillance criteria are not intended for informing antibiotic initiation because they
depend on information that might not be available when that decision must be made.
If, instead of Loeb criteria, these McGeer guidelines are used to retrospectively assess antibiotic
initiation appropriateness, they should be applied without inclusion of diagnostic criteria (e.g.,
positive urine culture, chest x-ray) that were not available at the time of antibiotic initiation.
▪ If diagnostic information that was not available in real-time is included in an antibiotic
appropriateness assessment, measures of inappropriate prescribing might be artificially
increased. This is because the metric would incorporate information (e.g., negative urine
culture) unavailable to the prescriber at the time of antibiotic initiation.
National Healthcare Safety Network (NHSN) criteria are used for active, resident-based,
prospective surveillance of events.
▪ Criteria might be based on laboratory results alone (CDI LabID) or include specific signs
and/or symptoms.
▪ Criteria are specifically designed to remove subjectivity and ensure accurate, reproducible,
and comparable surveillance data for a facility over time and across facilities.
▪ Participation in NHSN reporting can provide a way for facilities to benchmark infection
rates with other U.S. facilities.
▪ NHSN criteria are not intended for clinical decision making.