Measuring Staff Influenza Vaccination Coverage in U.S. Hospitals

Background:
Influenza vaccination rates among healthcare personnel nationally are suboptimal. Little is known about methods used by hospitals to monitor seasonal influenza vaccination coverage.

Objectives:
Characterize practices related to measuring staff influenza vaccination rates in U.S. hospitals.

Methods:
Self-administered electronic survey distributed in 2006 to infection control coordinators at a sample of 996 U.S. hospitals, selected randomly from 4,621 non-federal, short-stay, general medical and surgical hospitals listed in the 2004 American Hospital Association Annual Survey Database. The survey response rate was 55.7%. Weighting was used to account for stratified sampling design and non-response.

Results:
Most hospitals offered influenza vaccine to employees (100%) and credentialed medical staff (attending/independent practitioners) (93.9%); offering to medical students/residents was less frequent (58.1%). Although 91.7% of hospitals tracked vaccines given, only 68.7% measured vaccination coverage rates (mean reported coverage: 54.8%). Most hospitals measuring coverage included employees (86.9%) in reported coverage rates, while contract staff (39.4%), credentialed medical staff (44.0%), and students/residents (15.4%) were less commonly included. Of hospitals measuring coverage, 56.2% excluded contraindicated persons and 49.3% excluded persons refusing vaccination from coverage rates. Public hospitals, small hospitals (<100 beds), and hospitals in the South were significantly less likely to measure vaccination coverage. Hospitals with policies requiring, strongly encouraging or recommending influenza vaccination for all staff and staff with close patient contact were more likely to measure coverage (p<0.05 for both) than hospitals with policies not specifically addressing influenza vaccination.

Conclusions:
Since 2007, hospitals must measure annual influenza vaccination coverage among employees and independent practitioners to maintain accreditation. Hospitals vary in staff types included and whether contraindicated persons and vaccine refusers are included in influenza coverage measurements. Standardized measurement methods may improve comparability of hospital-reported vaccination rates. Measuring coverage among staff in a manner that facilitates identification of occupational groups with low vaccination rates may be helpful in developing targeted interventions.