Healthcare-associated infection surveillance methodologies.

Active or passive

active: trained personnel use various data sources to identify events;
passive: non-trained personnel identify and report events to infection prevention and control personnel.

Prospective or retrospective

prospective: monitoring patients while still in the institution; includes post-discharge period for SSI:
- visibility of infection control practitioner on wards (if active surveillance);
- timely analysis and feedback;
- labour intensive, costly;
retrospective: case-finding based solely on chart review after patient discharged.

Patient-based or laboratory-based

patient-based: monitoring patients for events, risk factors, and procedures and practices related to patient care:
- requires ward/unit rounds;
- includes discussions with caregivers/ physicians;
laboratory-based: case-finding based solely on positive laboratory findings:
- events may be missed;
- colonization.

Incidence or prevalence

incidence: measure new events occurring during some defined time period;
prevalence: measure all events occurring at either a point in time or during some defined time period.

Priority-directed (targeted) or comprehensive

priority-directed: Objectives for surveillance are defined and focused on specific events and/or patients:
- usually less resource intensive/costly;
comprehensive: continuous monitoring of all patients for all events:
- facility-wide;
- usually more resource intensive/costly.

Risk-adjusted or crude

risk-adjusted: Rates are controlled for variations the distribution of major risk factor(s) associated with an event’s occurrence:
- comparison of rates possible;
crude: Rates assume equal distribution of risk factors for all events:
- comparison of rates not possible.

Link to European IC/HH Core Competencies

Area 3. Surveillance and investigation of healthcare associated infection (HAI)

References

CDC Outline For Healthcare-Associated Infections Surveillance, 2006
Perl TM, Chaiwarit R. Surveillance: An Overview. In: Lautenbach E, Woeltje KF, Malani PN Eds. Practical Healthcare Epidemiology, Ed. Society for Healthcare Epidemiology of America, University of Chicago Press, Chicago, USA, 2010:111-142