Table 2.

Characteristics of studies included for analysis

Study	Population	Ascertainment	Intervention group	Comparison group
Nonhospital setting
Cluster randomized controlled trials
Dey et al.14	Nurses Administrators Ancillary staff	Vaccine provider submitted claim forms for reimbursement for vaccine	Campaign components as for comparison group Nurse raised awareness, and provided education and promotional material	Letter about free vaccine Free vaccine from general practitioner
Hayward et al.15	Full- and part-time employees	Not reported	New influenza vaccine policy Lead nurses trained as advocates Education letter for staff Three vaccine clinics with night shift	Letter explaining that adults with chronic disease should be vaccinated No active vaccine promotion
Kimura et al.16	Nurses Nurse assistants Housekeeping Rehabilitation therapists	Self-administered questionnaire to all health care workers	Arm 1: educational video and information Arm 2: publicized free vaccine day Arm 3: interventions of both arm 1 and arm 2	No intervention
Lemaitre et al.17	Caregivers Technicians Administrators	Intervention group: interview with study team Comparison group: self-administered questionnaire	Promotional posters, leaflets Information meeting with study team Face-to-face interview with all staff	Routine information on vaccine
Before-and-after with control
Tannenbaum et al.18	Nurses Nurses’ aides Other professions Orderies Housekeeping staff	Public health data Tracked on-site vaccination Self-administered questionnaire for off-site vaccination	5 information sessions by doctors Informational memos, posters 3 vaccine clinics over 2 wk	No intervention
Hospital setting
Randomized controlled trial
Doratotaj et al.19*	Medical residents Nurses Physicians	Vaccination rates reported by on-site vaccine clinics	Comparison campaign plus one or more of the following: Letter from infectious diseases department Raffle ticket for $3000 vacation	Educational poster or newsletter Department meetings Extra vaccine clinics
Randomized controlled trial
Ohrt and McKinney20	Medical residents	Nurses recorded vaccination rates	Comparison campaign plus one or more of the following: Letter from chief of infectious diseases Personalized phone call	Mailed educational memo Multiple vaccine clinics
Before-and-after with control
Harbarth et al.21	Physicians Nurses’ aides Nurses Housekeeping staff Other	Not reported	Comparison campaign plus: Educational conferences on issues identified by staff questionnaire Mobile vaccine cart	Newsletters and posters Email reminders Personal letter with paycheck Free vaccine
Polgreen et al.22	Medical residents	Not reported	Comparison campaign plus: Directors given feedback on rates Vaccines offered at meetings	Free vaccine for 4 wk + extra 4 wk Email/poster advertising
Zimmerman et al.23	Staff with direct patient contact Staff with indirect patient contact Business and administrative staff	Records from paper logs at each site	Comparison campaign plus one or more of the following: Incentive (e.g., lottery gift card, party) Mobile vaccine carts	Free vaccine Promotional material, letter to chief executives Peer vaccination Vaccine champion
Interrupted time series
Bertin et al.24†	Paid workers Volunteers	Rates (as captured by declination forms) reported by vaccine clinics	After Oct. 17, 2005: Mandatory intranet declination Feedback on rates Letter from upper management	Before intervention (1997–2005): Paper declination Senior staff support or champion Promotion of vaccination by physicians
Wicker25	Nurses Physicians Other staff	Not reported	After Jan 7, 2009 — comparison campaign plus: Mandatory masks for unvaccinated workers	2003/2004 to Jan 7, 2009: Education and publicity Free vaccine Mobile vaccine carts

^*Nonsignificant differences across comparison groups (p = 0.66).

^†The authors reported two campaigns, in 2004 and 2005. Only the 2005 campaign, for which the authors compared the difference in coverage rates between 2005 and the previous 9-year period, was considered for the current analysis.