Effectiveness & cost-effectiveness of vaccinating healthcare workers against influenza, and strategies to improve uptake

Dr Rachel Jordan University of Birmingham, UK

Amanda Burls, Beverley Wake, Pelham Barton, Babatunde Olowokure, Esther Albon, Jeremy Hawker

Overview

Background Effectiveness of influenza vaccine

in HCW Effectiveness in protecting patients Cost-effectiveness Barriers Interventions to improve uptake

Influenza vaccine and HCW

Influenza important public health problem…

Significant mortality & morbidity in elderly & high risk groups

Vaccinate most at risk Also provide indirect protection eg HCWs,

carers Recommended by WHO (& most of Europe) Uptake in Europe <25% [UK~13%]

Methodology

Series of systematic review sub-q’s Cochrane Library, MEDLINE, EMBASE

etc to June 2004 Independent data extraction & quality

assessment Primary studies – series of questions Updates

Effectiveness in HCW

Study DescriptionVaccine

match/epidemic

Wilde1992US

RCTVaccine v placebo

3 years361 person-

winters.

Year:1- Partial2- Good3- PartialEpidemic each

yr.

VACCINEEFFICACY

88% (47%, 97%)for Influenza

A(H3N2)89% (14%, 99%)for Influenza B.

Weingarten

1988US

RCTVaccine (91) v

placebo (88)

Poor match.Epidemic

present

ADVERSEEVENTS

Sore arm51% vaccinated vs

7% p<0.05Erythema

11% vaccinated vs 0% control

p<0.05

Demicheli2000

Systematicreview

3 RCTs

Good matchEpidemic

present

ABSENTEEISMIN HEALTHY

ADULTS

Reduction:0.4 days/person

vaccinated (95%CI 0.1, 0.8)

Protection for patientsPotter 1997 Carman 2000 Hayward 2006

Influenza epidemic

1994-5 1996-7 2003-4

Number of clusters

12 20 44

Setting Long-term-care geriatric hospitals in Scotland UK Care homes

Vaccine match Reasonable match

Good match Reasonable match

Number of HCW 1078 offeredvaccination

1217 offered vaccination 1743 (884 int/859 control) offered vacc

HCW vaccine uptake rate

Control = not given

Intervention = 61%

Control = 5%Intervention = 51%

Control = 5.9%Intervention = 48.2%

Number of patients

1059 (490 intervention569 control)

1437 (749 intervention 569 control)

2604(1233 intervention 1371 control)

Mortality results 17% (control) 10%

(intervention)p=0.013 (OR 0.56)

154/688 (22.4%) control102/749 (13.6%)

intervention OR 0.58 (95%CI 0.4-

0.84) Adj: OR 0.61 (0.36-1.04)

203/1323 (15.3%) con140/1249 (11.2%) interventionRate Diff -0.05 (-0.07, -0.02)

Cost-effectiveness Methods: Simple economic model

HCW Vaccination programme vs no prog Carman et al 2000 UK 2003-4 costs

Staff, vaccine, absenteeism Benefits discounted at 3.5%

Patient mortality, life expectancy Updated to include Hayward 2006 et al

Results

Carman 2000:

Base case Cost saving £12/vaccinee

No absenteeism CE £51/life yr gained

Pessimistic scenario

CE £405/life yr gained

Hayward 2006: pessimistic

CE £274/life yr gained

Barriers to vaccination

Large number of surveys Variety of designs,

settings and personnel Range of response rates

COMMON REASONS FOR REFUSING Fear of side effects Fear vaccine causes

flu Dislike of injections Unaware available Unaware useful Forgetting/lack of

time Perceived low risk of

contracting influenza

How do we improve uptake?

Common themes: Convenience & education

5 RCTs – range of interventions

Many before/after studies or descriptive evaluations of programmes

Evidence….RCTs Promotional/education campaigns –

little effect?Study Intervention Control

Dey 2001Manchester, primary care teams

Letter; posters; PH Nurse promotion: 21.9%

Letter: 21.0%

Kimura 2007S California

Educational campaign: 34% OR 1.3 (95%CI 0.8, 2.3)

No intervention27%

Doratotaj 2008Ohio: Tertiary care

Educational letter: 39%Letter + raffle: 44.5% (NS diff)

No offer: 38%

Evidence….RCTs Promotion + education + local

vaccination

Study Intervention Control

Hayward 2006UK nursing homes

Lead nurse promotion; letter; vacc clinics: 35.4%

No offer: 5%

Kimura 2007S California

Educational campaign + vaccine day: 53% OR 3.5 (95%CI 2.2, 5.7)

No intervention27%

Evidence….before/after Mobile carts – potential greatest effect?

Study Intervention Before After

Cooper 2002Australia - hospital

Mobile cart + promotion“Needles on Wheels”

8% 49%(81% in staff with pt contact)

Sartor 2004France – acute care hospital

Educational campaign + mobile cart

6% 32%(71% medical staff)

Evidence…. Combinations of:

Information/marketing convenience

Vaccine clinics + mandatory declination report via intranet eg Bertin 2007, Cleveland Hospital 55% after vs 38% before

Convenience + individual feedback & follow-up eg McCullers 2006, Pediatric Cancer

Hospital 80% after vs 45% before

Conclusions

Vaccinating HCW is effective & cost-effective

Uptake is still low Barriers are known Still lack of trials demonstrating

best methods of improving uptake

Implications

We need good RCTs of methods to improve uptake

Mobile carts combined with other methods promising

Mandatory declination? Individual feedback/follow-up?

Acknowledgements

Main funders: European Scientific Working Group on Influenza