Influenza vaccination in healthcare workers: A comprehensive critical appraisal of the literature

Figures & data

Table 1. List of excluded studies with reasons.

Excluded study (with reasons)	Reasons for exclusion
Brien et al.^12	Did not perform a comprehensive search (only 1 database, namely PubMed, was consulted)
Collange et al.^13	Did not perform a comprehensive search (only 1 database, namely PubMed, was consulted)
Hollmeyer et al.^14	Did not perform a comprehensive search (only 1 database, namely PubMed, was consulted)
Hollmeyer et al.^15	Did not perform a comprehensive search (only 1 database, namely PubMed, was consulted)
Thomas et al.^16	Old systematic review and meta-analysis, updated by Thomas et al.^17
Thomas et al.^18	Old systematic review and meta-analysis, updated by Thomas et al.^17
Thomas et al.^19	Old systematic review and meta-analysis, updated by Thomas et al.^17
Thomas et al.^20	Old systematic review and meta-analysis, updated by Thomas et al.^17
Thomas et al.^21	Old systematic review and meta-analysis, updated by Thomas et al.^17

Figure 1. The “Preferred Reporting Items for Systematic Reviews and Meta-analyses” (PRISMA) flow-chart for the selection and inclusion of studies in the present umbrella review.

Table 2. List of coded topics and their respective references.

Topic synthesized	Number of studies	References
Prevalence/incidence of influenza among HCWs	1	Lietz et al.^22
Influenza-related KABs	2	Gambhir et al.^23
		Ng and Lai^24
Influenza-related risk perceptions among HCWs	2	Koh et al.^25 Yiwen et al.^26
Adherence of HCWs to influenza vaccination	4	Bish et al.^27 La Torre et al.^28
		Maggiore et al.^29
		Prematunge et al.^30
Determinants of influenza vaccine uptake among HCWs	8	Bish et al.^27 La Torre et al.^28
		Nowak et al.^31
		Prematunge et al.^30
		Riphagen-Dalhuisen et al.^32
		Schmid et al.^33
		Vasilevska et al.^34
		Yiwen et al.^26
Effect of influenza vaccination among HCWs on HCWs themselves	5	Kliner et al.^35 Kuster et al.^36 Michiels et al.^37
		Ng and Lai^24
		Restivo et al.^38
Effect of influenza vaccination among HCWs on patients	6	Ahmed et al.^39 De Serres et al.^40
		Dolan et al.^41
		Kliner et al.^35
		Michiels et al.^37
		Thomas et al.^17
Strategies for improving vaccination coverage among HCWs	7	Corace et al.^42 Lam et al.^43 Lytras et al.^44
		Pitts et al.^45
		Rashid et al.^46
		Schmidt et al.^47
		Siemieniuk et al.^48
Economic impact of influenza vaccination among HCWs	1	Burls et al.^49

Table 3. Characteristics of the included systematic reviews.

Reference	Searched databases	Study protocol	Number of synthesized studies	Number of studied subjects	Outcome(s)	Main finding(s)	Quality assessment	Conflicts of interest	AMSTAR score
Bish et al.^27	PubMed, WoS	Not available	19 studies	33,985 HCWs	Willingness to vaccinate themselves against pandemic influenza	Intention associated with higher perceived susceptibility to H1N1, higher perceived severity of H1N1, higher perceived benefits, lower perceived costs of vaccination, older age, male gender, not being a nurse, wish to protect oneself and others, beliefs in vaccine safety and effectiveness, past influenza vaccinations, adequate knowledge and information (received from official sources), having previously suffered from influenza, receiving recommendation from respected HCW	Not performed	Disclosed	3
					Intention to being vaccinated	22- 83%
					Adherence to vaccination	13-53%
Corace et al.^42	MEDLINE, EMBASE, CINAHL, PsycINFO, The Joanna Briggs Institute, SocINDEX, and the Cochrane Database of Systematic Reviews	Not available	10 studies	7,312 HCWs	Impact of behavior change frameworks-based programs	It successfully predicted 85-95% of HCW influenza vaccination uptake	Performed		5
Gambhir et al.^23	PubMed/MEDLINE, Embase	Not available	3 cross-sectional studies	1,017 HCWs	Swine influenza-related KABs	Socio-demographic variables, clinical versus pre-clinical students	Not performed		5
					Knowledge and awareness about swine influenza vaccine	31.5-82.3%
Koh et al.^25	CINAHL, Ovid, PubMed, ScienceDirect, Scopus and Wiley InterScience	Not available	14 quantitative studies and 2 qualitative studies, of which 3 focusing on influenza	1,762 HCWs	Risk perceptions towards pandemic influenza	Working in tertiary hospitals versus community hospitals	Not performed	Not available	4
Lam et al.^43	MEDLINE, EMBASE, CINAHL, Database of Abstracts of Reviews of Effects, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials and Proquest (for dissertations and theses)	Not available	12 studies	55,605 HCWs, of which 34,834 cases	Determinants of the effectiveness of influenza vaccination campaigns	Interventions combining different strategies in LTCIs seem to be the most effective	Performed	Disclosed	6
Maggiore et al.^29	PubMed/MEDLINE and Scopus	Not available	Authors data + 17 studies, of which 3 focusing on influenza	At least 50,360 HCWs, of which at least 6,001 were evaluated with respect to influenza vaccination	Adherence to influenza vaccination	From <10% to 56%	Performed	Not available	5
					Strategies for improving vaccination coverage	A complex, multifaceted intervention succeeded in increasing vaccination coverage
Pitts et al.^45	MEDLINE, Embase, the Cochrane Library, CINAHL, SCIE, and Conference Proceedings Citations Index	Registered in PROSPERO CRD42012002913	12 observational studies	At least 113,239 HCWs	Impact of a program implementing mandatory influenza vaccination among HCWs	Vaccination rates increased, exceeding 94%.	Performed	Disclosed	6
Prematunge et al.^30	MEDLINE, PubMed, EMBASE, PsycINFO, CINHAL, AMED, Cochrane Library, ProQuest, and grey literature sources	Not available	20 studies (1 focus group, 1 cohort study, 18 cross-sectional studies)	22,348 HCWs	Influenza vaccination coverage	From 9% to 29%	Not performed	Disclosed	5
					Determinants of influenza vaccination uptake	Believing that vaccine is safe and effective and that influenza is a serious disease
Rashid et al.^46	MEDLINE, Embase, the Cochrane Library, CINAHL, PsycINFO + grey literature	Not available	12 RCTs	193,924 HCWs	Interventions for increasing influenza vaccination rate among HCWs	Combined strategies seemed to be more effective than isolate approaches	Performed	Disclosed	7
Restivo et al.^38	PubMed/MEDLINE, Scopus, Embase, ISI/WoS	Registered in PROSPERO CRD42017054854	2 studies (1 case-control study, 1 cohort study)	2,062 HCWs	Vaccine effectiveness among HCWs	From 70.5% to 90.5% [95%CI 73.5-97.3%]	Not performed	Nothing to disclose	5
Schmid et al.^33	MEDLINE, LILACS, Embase, IBSS, PsychInfo, IMEMR (GIM), Cinahl, IMSEAR (GIM), the Cochrane Library, AIM (GIM), WoS, WPRIM (GIM)	Not available	470 studies, of which 117 specifically focusing on HCWs		Influenza vaccine hesitancy, and the main perceived barriers to vaccine uptake	A low risk perception, denial of the clinical/social benefit of vaccination practices, a low social pressure, lack of perceived behavioral control, not having been previously vaccinated, not having previously suffered from influenza, lack of influenza-specific knowledge, lack of access to vaccination facilities, and socio-demographic variables predicted low vaccine uptake	Not performed	Disclosed	4
Yiwen et al.^26	CINAHL, PubMed, SCOPUS, ScienceDirect, Sociological Abstracts, PsycINFO, and WoS	Published	10 quantitative studies and 1 qualitative study, of which 5 focusing specifically on influenza	9,676 HCWs	HCW's risk perceptions and impact of risk perceptions on risk-mitigating strategies	Relationship between HWCs' risk perceptions and risk-mitigating strategies needs to be further elucidated	Performed	Disclosed	6

Table 4. Characteristics of the included meta-analyses.

Reference	Searched databases	Study protocol	Number of synthesized studies	Number of studied subjects	Outcome(s)	Main finding(s)	Quality assessment	Conflicts of interest	AMSTAR score
Ahmed et al.^39	MEDLINE, Embase, CINAHL, WoS, and the Cochrane Library	Not available	4 cluster RCTs and 4 observational studies (2 cohort and 2 case-control studies)	8,468 residents	Overall impact of the influenza vaccination	The overall quality of the evidence was moderate	Performed	Nothing to disclose	6
					Reduction in patient mortality	It may provide a protective effect (RR 0.71 [95%CI 0.59–0.85], RD −44 [95%CI from −23 to −62], ΔRR% 29% [95%CI 15-41%]), whose evidence quality is moderate
					Reduction in laboratory-confirmed influenza cases	It may provide a protective effect (RR 0.80 [95%CI 0.31–2.08], RD −13 [95%CI from −44 to 69]), whose evidence quality is low
					Reduction in ILI episodes	It may provide a protective effective (RR 0.58 [95%CI 0.46–0.73], RD −68 [95%CI from −44 to −87], ΔRR% 42% [95% CI 27–54%), whose evidence quality is low
					Reduction in patient hospitalization rate	No effect (RR 0.91 [95%CI 0.69–1.19], RD −9 [95%CI from −29 to 18])
De Serres et al.^40	MEDLINE, US CDC, the Cochrane Library	Not available	4 RCTs	8,490 residents	Impact of influenza vaccination among HCWs	At least from 6,000 to 32,000 HCWs would need to be vaccinated in order to avert a single patient death	Performed	Disclosed	NA, being a critical review and appraisal of already published systematic reviews and meta-analyses
Kuster et al.^36	OVID MEDLINE and EMBASE	Not available	29 studies (97 influenza seasons)	58,245 HCWs	All infections in unvaccinated HCWs per season	IR 18.7 (95% CI, 15.8 to 22.1)	Performed	Disclosed	7
					All infections in unvaccinated HCWs	IRR 3.4 (95% CI, 1.2 to 5.7)
					All infections in vaccinated HCWs per season	IR 6.5 (95% CI, 4.6 to 9.1)
					All infections in vaccinated HCWs	IRR 5.4 (95% CI, 2.8 to 8.0)
					Symptomatic infections in unvaccinated HCWs per season	IR 7.5 (95% CI, 4.9 to 11.7)
					Symptomatic infections in unvaccinated HCWs	IRR 1.5 (95% CI, 0.4 to 2.5)
					Symptomatic infections in vaccinated HCWs per season	IR 4.8 (95% CI, 3.2 to 7.2)
					Symptomatic infections in vaccinated HCWs	IRR 1.6 [95%CI 0.5-2.7]
La Torre et al.^28	PubMed/MEDLINE, Scopus, Google Scholar, ISI/Web of Knowledge	Not available	15 studies (qualitatively synthesized) and 6 studies (quantitatively synthesized)	At least 20,296 HCWs (1 study did not report the number of total subjects studied)	Proportion of influenza vaccination rate among nurses	13.47% [95%CI 9.58-17.90%]	Performed	Not available	7
					Proportion of influenza vaccination rate among ancillary workers	12.52% [95%CI 9.97-15.31%]
					Ideas/reasons encouraging vaccination such as self protection	70%–94.3%
					family protection	24%–69%
					patients protection	26%–57.8%
					protection of other people	28.0%–58.2%
					being an healthcare worker	9.31%
					being elderly or affected by a chronic disease	21.33%
					Ideas preventing vaccination such as not caring about influenza	35.2%–57.1%
					doubts about vaccine efficacy	14.1%–43.8%
					fear of adverse effects	14%–30.6%
					being opposed to vaccination	2.3%–6.2%
					forgetfulness	8.5%
					believing that vaccines do not have a protective effect	12.1%
					believing that influenza is a mild disease	9.5%
Lietz et al.^22	Embase, MEDLINE, PsycINFO, CINAHL (all via OVID), PubMed and Google Scholar	Available upon request	26 studies (qualitatively synthesized) and 15 studies (quantitatively synthesized)	109,815 subjects, of which 72,281 HCWs	Occupational risk of influenza A H1N1 infection among HCWs during the 2009 pandemic	OR of 2.08 [95%CI 1.732.51]	Performed	Disclosed	7
					Overall influenza prevalence rate among HCWs	6.3%
Lytras et al.^44	MEDLINE and Scopus	Not available	46 studies	All studies with all HCWs, except for 3 studies with all HCWs with direct patient contact, 1 with physicians and nurses, 1 with medical residents and students, 2 all HCWs except physicians	Impact of interventions for increasing seasonal influenza vaccine coverage such as mandatory vaccination	RRunvacc 0.18 [95%CI 0.08-0.45]	Performed	Disclosed	7
					Declination statements	RRunvacc 0.64 [95%CI 0.45-0.92]
					Increased awareness	RRunvacc 0.83 [95% CI 0.71-0.97]
					Increased access	RRunvacc 0.88 [95%CI 0.78-1.00]
					Incentives	No significant difference
					Education	No effect (RRunvacc 0.96 [95%CI 0.84–1.10])
Ng and Lai^24	22 databases	Not available	3 RCTs	992 HCWs	Overall impact of vaccination	No definitive conclusions	Performed	Disclosed	8
					Reduction of laboratory-confirmed influenza cases and vaccine effectiveness	Significant protective effect; vaccine effectiveness of 88% [95%CI 59-96%]
					Reduction of number of ILI episodes	1.07 [95%CI 0.62-1.85]
					Reduction of days with ILI symptoms	Reduction by 0.12 days [95%CI 0.06-0.3]
					Reduction in amount of sick leave	Reduction by 0.08 days [95%CI 0.02-0.19]
Nowak et al.^31	US CDC	Not available	29 unpublished, primarily qualitative CDC-sponsored studies	2,090 HCWs (132 nurses, 1,811 doctors, 14 HCP, 75 clinical staff, 35 hospital service workers, 23 allied health professionals)	Influenza-related KABs among HCWs	Knowledge and favorable beliefs have increased throughout time, but many misperceptions (HCWs are not susceptible to influenza; influenza is a threat only to frail and sick people) persist, varying according to the type or category of HCW	Not performed	Disclosed	Not applicable, being a qualitative meta-analysis
Siemieniuk et al.^48	MEDLINE, Embase, CENTRAL, WoS, Scopus, and CINAHL + gray literature	Registered in PROSPERO CRD42013006122	121 studies with 174 comparisons, (132 before/after studies, 23 randomized trials, 12 surveys, 7 cohort studies, and 1 case-control study)	From 120,670 HCWs to 764,570 HCWs, according to the synthesized strategy intervention	Strategies for improving influenza vaccination coverage among HCWs such as condition of service	93% reduction [95%CI 91-95%]	Performed	Disclosed	8
					Vaccine-or-mask	74% reduction [95%CI 61-88%]
					Declination forms	41% reduction [95%CI 35–46%]
					Audit-and-feedback	35% reduction [95%CI 29–40%]
					Increased vaccine access	32% reduction [95%CI 27–36%]
					Role models	30% [95%CI 24–36%]
					Peer-vaccination	29% reduction [95%CI10–45%]
					Incentives	28% reduction [95%CI21– 33%]
					Education/promotion only	11% reduction [95%CI 7–16%)]
Riphagen-Dalhuisen et al.^32	PubMed and Embase	Not available	13 studies	84,880 HCWs	Predictors of seasonal influenza vaccination such as knowing that the vaccine is effective	RR 2.22 [95%CI 1.93 to 2.54]	Not performed	Disclosed	5
					Being willing to prevent influenza transmission	RR 2.31 [95%CI 1.97 to 2.70]
					Believing that influenza is highly contagious	RR 2.25 [95%CI 1.66 to 3.05]
					Believing that influenza prevention is important	RR 3.63 [95%CI 2.87 to 4.59]
					Having a family that is usually vaccinated	RR 2.32 [95%CI 1.64 to 3.28]
Schmidt et al.^47	PubMed and Scopus	Not available	10 studies	13,322 subjects	Impact of strategies for improving influenza vaccination coverage among HCWs	Interventions combining educational and promotional components seem to be the most effective	Performed	Not available	7
					Impact of the quality of trials and year of publication	The quality of trials plays a major role
Thomas et al.^17	CENTRAL, MEDLINE, EMBAS, WoS, Biological Abstracts, SCIE	Available	4 cluster RCTs and 1 cohort study	12,742 HCWs (qualitatively synthesized) and 5,896 residents (quantitatively synthesized)	Impact of influenza vaccination among HCWs caring for individuals ≥60 years in LTCIs in terms of reduction of laboratory-proven infections	RD 0 [95% CI −0.03–0.03]	Performed	Disclosed	10
					Reduction of lower respiratory tract infection in residents	From 6% to 4% (RD −0.02 [95% CI −0.04–0.01
					Reduced respiratory illness in residents	RD 0 [95% CI −0.02–0.02]
Vasilevska et al.^34	MEDLINE, Embase, and CINAHL	Not available	37 studies	67,384 HCWs	Determinants of vaccine acceptance such as desire for self-protection	OR 3.42 [95%CI) 2.42-4.82])	Performed	Disclosed	7
					Desire to protect family and friends	OR 3.28 [95% CI 1.10-9.75])
					Concerns regarding safety and effectiveness	(OR 0.42 [95%CI 0.30-0.58])

Table 5. Characteristics of the included systematic appraisals of published studies and economic evaluations.

Reference	Searched databases	Study protocol	Number of synthesized studies	Outcome(s)	Main finding(s)	Risk of bias assessment	Conflicts of interest	AMSTAR score
Burls et al.^49	Cochrane library, CINAHL, NHSEED, HEED, DARE, MEDLINE and EMBASE	Not available	18 studies (3 RCTs, 3 cluster RCTs, 5 before/after studies, 7 surveys)	Reduction in mortality	Reduction from 17% to 10% (OR 0.56 [95%CI 0.4-0.8]) – OR 0.61, [95%CI 0.36-1.04]	Performed	Disclosed	5
				Vaccine effectiveness	88% [95%CI 47-97%]
				Strategies for improving vaccine uptake	Increase by 5-45%
				Economic analysis of influenza vaccination among HCWs	In the base case, vaccination was cost saving
Dolan et al.^41	22 databases + vaccine manufacturers, domain experts	Registered CRD420111092]	20 studies (4 RCTs, 10 observational studies; 6 reviews)	Overall impact of influenza vaccination among HCWs	It is likely to offer some protection, but further evidence is needed from acute care settings	Performed	Disclosed	6
				Reduction in cases of acute respiratory disease	Inconsistent effect
				Reduction in clinically defined cases of ILI	It is likely to offer some protection
				Reduction in GP consultations for ILI	Inconsistent effect across different influenza seasons
				Reduction in outbreaks/clusters of ILI	It is likely to offer some protection
				Reduction in laboratory confirmed cases of influenza	Small non significant effect
				Reduction in laboratory confirmed outbreaks of influenza	No statistically significant effect
				Reduction in respiratory mortality	Small non significant effect
				Reduction of all-cause mortality	It is likely to offer some protection
				Impact on hospitalization	No clear effect
Kliner et al.^35	MEDLINE, Embase, CINAHL, AMED and HMIC	Available	11 reviews	Impact of influenza vaccination among HCWs	No “straightforward evidence” of employer and patient safety benefits of influenza vaccination among HCWs	Performed	Disclosed	8
Michiels et al.^37	PubMed, the Cochrane library	Not available	3 studies (2 randomized trials and 1 systematic review and meta-analysis)	Impact of vaccination on HCWs	Effectiveness of 53% Effectiveness in young physicians (30 years) aOR 0.35 [95%CI 0.13–0.96], efficacy 0.10 [95%CI 0.01–0.75]	Performed	Disclosed	6
				Impact of vaccination on patients	Not significant

Figure 2. Influenza vaccination uptake among healthcare workers (HCWs) worldwide, between 2006 and 2015. Adapted from (To et al., 2016), reference 50.

Figure 3. Temporal trend of influenza vaccination uptake among healthcare workers (HCWs) worldwide, between 2006 and 2015. Adapted from (To et al., 2016), reference 50.

Table 6. Narrative meta-synthesis reporting the main outcomes of the current umbrella review concerning influenza vaccination among healthcare workers. Abbreviations: HCWs (healthcare workers); KABs (knowledge, attitudes and beliefs).

Topic synthesized	Main outcome(s)
Prevalence/incidence of influenza among HCWs	HCWs are a risk group
Influenza-related KABs	Higher and more favourable among medical doctors
	Positive KABs have increased throughout the years, even though misconceptions persist
Influenza-related risk perceptions among HCWs	Variable according to type or category of HCWs
Adherence of HCWs to influenza vaccination	Low coverage, despite recommendations
	In some countries have increased throughout the years
	Higher among medical doctors
Determinants of influenza vaccine uptake among HCWs	Extensively studied
	Different categories including KABs, past experiences and socio-demographic variables
Effects of influenza vaccination among HCWs on HCWs themselves	Influenza vaccination has a protective effect for HCWs
Effects of influenza vaccination among HCWs on patients	Controversial effects
Strategies for improving vaccination coverage among HCWs	Mandatory vaccination is effective in increasing vaccination coverage among HCWs
	Soft mandate-based programs are effective as well
	Multi-faceted, complex and integrated programs seem to be the most effective approaches
Economic impact of influenza vaccination among HCWs	Potentially cost saving

Table 7. Search strategy of the present umbrella review.

Search strategy item	Details
String of keywords used	(influenza OR flu) AND (vaccination OR vaccine OR vaccines OR immunization OR immunisation OR belief OR beliefs OR perception OR perceptions OR awareness OR knowledge) AND (“healthcare worker” OR “healthcare workers” OR “healthcare personnel” OR “healthcare staff” OR “health worker” OR “health workers” OR “health personnel” OR “health staff” OR physicians OR physician OR doctors OR doctor OR nurses OR nurse OR practitioners OR practitioner)
Databases searched	ProQuest Central, ABI/INFORM Complete, MEDLINE/PubMed (NLM), ScienceDirect Journals (Elsevier), Elsevier (CrossRef), Scopus (Elsevier), SpringerLink, PMC (PubMed Central), Springer (CrossRef), SAGE Journals, JSTOR Archival Journals, Taylor & Francis Online – Journals, Directory of Open Access Journals (DOAJ), Oxford University Press (CrossRef), Oxford Journals (Oxford University Press), BMJ Journals (BMJ Publishing Group), Wiley Online Library, Wiley (CrossRef), NARCIS (Royal Netherlands Academy of Arts and Sciences), Wolters Kluwer - Ovid - Lippincott Williams & Wilkins (CrossRef), Lippincott Williams & Wilkins Journals (Wolters Kluwer Health), the Cochrane Database of Systematic Reviews (CDSR), the Cochrane Central Register of Controlled Trials (CENTRAL), Database of Abstracts of Reviews of Effects (DARE), the Cochrane Methodology Register (CMR), Health Technology Assessment Database (HTA) NHS Economic Evaluation Database
Inclusion criteria	P: HCWs
	I: strategies for improving vaccination coverage among HCWs
	C: vaccinated HCWs versus unvaccinated HCWs
	O: reduction in influenza cases, patient hospitalization and mortality
	Study design: systematic review and/or meta-analysis
Exclusion criteria	Study design: duplicated or not updated systematic review and/or meta-analysis
Time filter	None applied (from inception to 18^th April 2017)
Language filter	None applied (any language)
Target journals	American Journal of Preventive Medicine; BMJ Open; Canadian Medical Association Journal; Clinical Infectious Diseases; Health Affairs; Human Vaccines; Human Vaccines & Immunotherapeutics; Influenza and Other Respiratory Viruses; Healthcare; JBI Library of Systematic Reviews; Journal of Clinical and Diagnostic Research; Occupational and Environmental Medicine; The Cochrane Database of Systematic Reviews; The Journal of Hospital Infection; Vaccine

Brien S, Kwong JC, Buckeridge DL. The determinants of 2009 pandemic A/H1N1 influenza vaccination: a systematic review. Vaccine 2012; 30(7):1255-64; https://doi.org/10.1016/j.vaccine.2011.12.089

 PubMed Web of Science ®Google Scholar

Collange F, Verger P, Launay O, Pulcini C. Knowledge, attitudes, beliefs and behaviors of general practitioners/family physicians toward their own vaccination: A systematic review. Hum Vaccin Immunother 2016; 12(5):1282-92; https://doi.org/10.1080/21645515.2015.1138024

 PubMed Web of Science ®Google Scholar

Hollmeyer HG, Hayden F, Poland G, Buchholz U. Influenza vaccination of health care workers in hospitals–a review of studies on attitudes and predictors. Vaccine 2009; 27(30):3935-44 [accessed June 7 2017]; https://doi.org/10.1016/j.vaccine.2009.03.056

 PubMed Web of Science ®Google Scholar

Hollmeyer H, Hayden F, Mounts A, Buchholz U. Review: interventions to increase influenza vaccination among healthcare workers in hospitals. Influenza Other Respir Viruses 2013; 7:604-21; PMID:22984794; https://doi.org/10.1111/irv.12002

 PubMed Web of Science ®Google Scholar

Thomas RE, Jefferson T, Demicheli V, Rivetti D. Influenza vaccination for healthcare workers who work with the elderly. Cochrane Database Syst Rev 2006 Jul 19;(3):CD005187

 PubMed Web of Science ®Google Scholar

Thomas RE, Jefferson T, Lasserson TJ. Influenza vaccination for healthcare workers who care for people aged 60 or older living in long-term care institutions. Cochrane Database Syst Rev 2016 Jun 2;(6):CD005187

 PubMed Web of Science ®Google Scholar

Thomas RE, Jefferson TO, Demicheli V, Rivetti D. Influenza vaccination for health-care workers who work with elderly people in institutions: a systematic review. Lancet Infect Dis 2006; 6(5):273-9; https://doi.org/10.1016/S1473-3099(06)70462-5

 PubMed Web of Science ®Google Scholar

Thomas RE, Jefferson T, Lasserson TJ. Influenza vaccination for healthcare workers who work with the elderly: systematic review. Vaccine 2010; 29(2):344-56

 PubMed Web of Science ®Google Scholar

Thomas RE, Jefferson T, Lasserson TJ. Influenza vaccination for healthcare workers who work with the elderly. Cochrane Database Syst Rev 2010 Feb 17;(2):CD005187

 PubMed Web of Science ®Google Scholar

Thomas RE, Jefferson T, Lasserson TJ. Influenza vaccination for healthcare workers who care for people aged 60 or older living in long-term care institutions. Cochrane Database Syst Rev 2013 Jul 22;(7):CD005187

 PubMed Web of Science ®Google Scholar

Lietz J, Westermann C, Nienhaus A, Schablon A. The Occupational Risk of Influenza A (H1N1) Infection among Healthcare Personnel during the 2009 Pandemic: A Systematic Review and Meta-Analysis of Observational Studies. PLoS One 2016; 11(8):e0162061

 PubMed Web of Science ®Google Scholar

Gambhir RS, Pannu PR, Nanda T, Arora G, Kaur A. Knowledge and Awareness Regarding Swine-Influenza A (H1N1) Virus Infection among Dental Professionals in India - A Systematic Review. J Clin Diagn Res 2016; 10(9):ZE10-ZE13

 PubMed Web of Science ®Google Scholar

Ng AN, Lai CK. Effectiveness of seasonal influenza vaccination in healthcare workers: a systematic review. J Hosp Infect 2011; 79(4):279-86

 PubMed Web of Science ®Google Scholar

Koh Y, Hegney DG, Drury V. Comprehensive systematic review of healthcare workers' perceptions of risk and use of coping strategies towards emerging respiratory infectious diseases. Int J Evid Based Healthc 2011; 9(4):403-19

 PubMedGoogle Scholar

Yiwen K, Hegney D, Drury V. A comprehensive systematic review of healthcare workers' perceptions of risk from exposure to emerging acute respiratory infectious diseases and the perceived effectiveness of strategies used to facilitate healthy coping in acute hospital and community healthcare settings. JBI Libr Syst Rev 2010; 8(23):917-971; PMID:27819952

 PubMedGoogle Scholar

Bish A, Yardley L, Nicoll A, Michie S. Factors associated with uptake of vaccination against pandemic influenza: a systematic review. Vaccine 2011; 29(38):6472-84

 PubMed Web of Science ®Google Scholar

La Torre G, Mannocci A, Ursillo P, Bontempi C, Firenze A, Panico MG, Sferrazza A, Ronga C, D'Anna A, Amodio E, Romano N, Boccia A. Prevalence of influenza vaccination among nurses and ancillary workers in Italy: systematic review and meta analysis. Hum Vaccin 2011; 7(7):728-33; https://doi.org/10.4161/hv.7.7.15413

 PubMed Web of Science ®Google Scholar

Maggiore UL, Scala C, Toletone A, Debarbieri N, Perria M, D'Amico B, Montecucco A, Martini M, Dini G, Durando P. Susceptibility to vaccine-preventable diseases and vaccination adherence among healthcare workers in Italy: A cross-sectional survey at a regional acute-care university hospital and a systematic review. Hum Vaccin Immunother 2017; 13(2):470-476; https://doi.org/10.1080/21645515.2017.1264746

 PubMed Web of Science ®Google Scholar

Prematunge C, Corace K, McCarthy A, Nair RC, Pugsley R, Garber G. Factors influencing pandemic influenza vaccination of healthcare workers–a systematic review. Vaccine 2012 Jul 6; 30(32):4733-43; https://doi.org/10.1016/j.vaccine.2012.05.018

 PubMed Web of Science ®Google Scholar

Nowak GJ, Sheedy K, Bursey K, Smith TM, Basket M. Promoting influenza vaccination: insights from a qualitative meta-analysis of 14 years of influenza-related communications research by U.S. Centers for Disease Control and Prevention (CDC). Vaccine 2015; 33(24):2741-56; https://doi.org/10.1016/j.vaccine.2015.04.064

 PubMed Web of Science ®Google Scholar

Riphagen-Dalhuisen J, Gefenaite G, Hak E. Predictors of seasonal influenza vaccination among healthcare workers in hospitals: a descriptive meta-analysis. Occup Environ Med 2012; 69(4):230-5; https://doi.org/10.1136/oemed-2011-100134

 PubMed Web of Science ®Google Scholar

Schmid P, Rauber D, Betsch C, Lidolt G, Denker ML. Barriers of Influenza Vaccination Intention and Behavior - A Systematic Review of Influenza Vaccine Hesitancy, 2005 - 2016. PLoS One 2017; 12(1):e0170550; https://doi.org/10.1371/journal.pone.0170550

 PubMed Web of Science ®Google Scholar

Vasilevska M, Ku J, Fisman DN. Factors associated with healthcare worker acceptance of vaccination: a systematic review and meta-analysis. Infect Control Hosp Epidemiol 2014; 35(6):699-708; https://doi.org/10.1086/676427

 PubMed Web of Science ®Google Scholar

Kliner M, Keenan A, Sinclair D, Ghebrehewet S, Garner P. Influenza vaccination for healthcare workers in the UK: appraisal of systematic reviews and policy options. BMJ Open 2016; 6(9):e012149; https://doi.org/10.1136/bmjopen-2016-012149

 PubMed Web of Science ®Google Scholar

Kuster SP, Shah PS, Coleman BL, Lam PP, Tong A, Wormsbecker A, McGeer A. Incidence of influenza in healthy adults and healthcare workers: a systematic review and meta-analysis. PLoS One 2011; 6(10):e26239; PMID:22028840; https://doi.org/10.1371/journal.pone.0026239

 PubMed Web of Science ®Google Scholar

Michiels B, Govaerts F, Remmen R, Vermeire E, Coenen S. A systematic review of the evidence on the effectiveness and risks of inactivated influenza vaccines in different target groups. Vaccine 2011; 29(49):9159-70; https://doi.org/10.1016/j.vaccine.2011.08.008

 PubMed Web of Science ®Google Scholar

Restivo V, Costantino C, Bono S, Maniglia M, Marchese V, Ventura G, Casuccio A, Tramuto F, Vitale F. Influenza vaccine effectiveness among high-risk groups: a systematic literature review and meta-analysis of case-control and cohort studies. Hum Vaccin Immunother 2017; in press. https://doi.org/10.1080/21645515.2017.1321722

 Web of Science ®Google Scholar

Ahmed F, Lindley MC, Allred N, Weinbaum CM, Grohskopf L. Effect of influenza vaccination of healthcare personnel on morbidity and mortality among patients: systematic review and grading of evidence. Clin Infect Dis 2014; 58(1):50-7; https://doi.org/10.1093/cid/cit580

 PubMed Web of Science ®Google Scholar

De Serres G, Skowronski DM, Ward BJ, Gardam M, Lemieux C, Yassi A, Patrick DM, Krajden M, Loeb M, Collignon P, Carrat F. Influenza Vaccination of Healthcare Workers: Critical Analysis of the Evidence for Patient Benefit Underpinning Policies of Enforcement. PLoS One 2017; 12(1):e0163586; https://doi.org/10.1371/journal.pone.0163586

 PubMed Web of Science ®Google Scholar

Dolan GP, Harris RC, Clarkson M, Sokal R, Morgan G, Mukaigawara M, Horiuchi H, Hale R, Stormont L, Béchard-Evans L, Chao YS, Eremin S, Martins S, Tam J, Peñalver J, Zanuzadana A, Nguyen-Van-Tam JS. Vaccination of healthcare workers to protect patients at increased risk of acute respiratory disease: summary of a systematic review. Influenza Other Respir Viruses 2013; 7 Suppl 2:93-6; https://doi.org/10.1111/irv.12087

 PubMed Web of Science ®Google Scholar

Corace KM, Srigley JA, Hargadon DP, Yu D, MacDonald TK, Fabrigar LR, Garber GE. Using behavior change frameworks to improve healthcare worker influenza vaccination rates: A systematic review. Vaccine 2016; 34(28):3235-42; https://doi.org/10.1016/j.vaccine.2016.04.071

 PubMed Web of Science ®Google Scholar

Lam PP, Chambers LW, MacDougall DM, McCarthy AE. Seasonal influenza vaccination campaigns for health care personnel: systematic review. CMAJ 2010; 182(12):E542-8; https://doi.org/10.1503/cmaj.091304

 PubMed Web of Science ®Google Scholar

Lytras T, Kopsachilis F, Mouratidou E, Papamichail D, Bonovas S. Interventions to increase seasonal influenza vaccine coverage in healthcare workers: A systematic review and meta-regression analysis. Hum Vaccin Immunother 2016; 12(3):671-81; PMID:26619125; https://doi.org/10.1080/21645515.2015.1106656

 PubMed Web of Science ®Google Scholar

Pitts SI, Maruthur NM, Millar KR, Perl TM, Segal J. A systematic review of mandatory influenza vaccination in healthcare personnel. Am J Prev Med 2014; 47(3):330-40; https://doi.org/10.1016/j.amepre.2014.05.035

 PubMed Web of Science ®Google Scholar

Rashid H, Yin JK, Ward K, King C, Seale H, Booy R. Assessing Interventions To Improve Influenza Vaccine Uptake Among Health Care Workers. Health Aff (Millwood) 2016; 35(2):284-92; https://doi.org/10.1377/hlthaff.2015.1087

 PubMed Web of Science ®Google Scholar

Schmidt S, Saulle R, Di Thiene D, Boccia A, La Torre G. Do the quality of the trials and the year of publication affect the efficacy of intervention to improve seasonal influenza vaccination among healthcare workers?: Results of a systematic review. Hum Vaccin Immunother 2013; 9(2):349-61; https://doi.org/10.4161/hv.22736

 PubMed Web of Science ®Google Scholar

Siemieniuk R, Coleman B, Shafiz S, Al-Den A, Bornsten S, Kean R, McGeer A, Goodliffe L. Interventions to increase healthcare worker influenza vaccination: a meta-analysis. Poster ID1713 presented at the IDWeek2014. Advancing Science, Improving Care. October 8-12 2014, Philadelphia, PA, USA. Available at https://idsa.confex.com/idsa/2014/webprogram/Paper47456.html

 Google Scholar

Burls A, Jordan R, Barton P, Olowokure B, Wake B, Albon E, Hawker J. Vaccinating healthcare workers against influenza to protect the vulnerable–is it a good use of healthcare resources? A systematic review of the evidence and an economic evaluation. Vaccine 2006; 24(19):4212-21; https://doi.org/10.1016/j.vaccine.2005.12.043

 PubMed Web of Science ®Google Scholar