An Improvement Project to Evaluate the Effectiveness of Different Reminders Designed to Increase the University Hospitals Birmingham NHS Foundation Trust's Staff Uptake of the Seasonal Influenza Vaccine
Phase: NA
Conditions: Influenza Vaccination
Sponsor: University of Warwick

Short Title: An improvement project around staffs' influenza vaccine uptake 
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PROTOCOL 
STUDY SUMMARY 
Study title 
An improvement project to evaluate the effectiveness of different reminders designed to increase 
the University Hospitals Birmingham NHS Foundation Trust’s staff uptake of the seasonal 
influenza vaccine  
Short study title  
An improvement project around staffs' influenza vaccine uptake 
 
Chief Investigator’s 
address and contact 
        Title / Name: 
Prof Richard J Lilford  
        Post: 
Professor/CLAHRC-West Midlands Director 
        Qualifications: 
PhD., FRCOG., FRCP., FFPH., DSc. (Hons) 
        Employer: 
Warwick Medical School 
        Address: 
Medical School Building  
University of Warwick, Coventry  
         Post Code: 
CV4 7AJ 
         Email: 
R.J.Lilford@warwick.ac.uk  
         Phone: 
02476575884 
 
 
Collaborator’s 
address and contact 
Title / Name: 
Dr Kelly Ann Schmidtke  
Post: 
Research Fellow 
Address: 
Warwick Business School 
University of Warwick 
Scarman Road, Coventry 
CV4 7AL 
Email: 
Kelly.Schmidtke@wbs.ac.uk 
Phone: 
07758933026 
 
 
Title / Name: 
Prof Ivo Vlaev  
 
Post: 
Professor 
 
Address: 
Warwick Business School 
University of Warwick 
Scarman Road, Coventry 
CV4 7AL 
 
Email: 
Ivo.Vlaev@wbs.ac.uk 
 
Phone: 
02476522945 
 
 
 
 
 
 
 
Title / Name: 
Mr Lawrence Tallon   
 
Post: 
Director of Strategy, Planning and Performance 
 
Address: 
University Hospitals Birmingham NHS Foundation Trust  
Trust Headquarters  
Queen Elizabeth Medical Centre  
PO Box 9551  
Main Drive, Edgbaston Birmingham  
B15 2PR 
 
Email: 
Lawrence.Tallon@uhb.nhs.uk 
 
 
 
Title / Name: 
Dr. Peter Nightingale 
 
Post: 
Statistician 
 
Address: 
Institute of Translational Medicine, University Hospitals 
Birmingham NHS Foundation Trust, Birmingham, UK,  
B15 2TH 
 
Email: 
peter.nightingale@uhb.nhs.uk  
 

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Title / Name: 
Suzy Gallier 
Post: 
Clinical Business Development Lead 
Address: 
University Hospitals Birmingham NHS Foundation Trust  
Level 1 Queen Elizabeth Hospital Birmingham  
Mindelsohn Way, Edgbaston, Birmingham,  
B15 2GW 
Email: 
 
 
 
suzy.gallier@uhb.nhs.uk  
 
 
Title / Name: 
Katherine Reeves 
Post: 
Statistical Intelligence Analyst 
Address: 
University Hospitals Birmingham NHS Foundation Trust  
Level 1 Queen Elizabeth Hospital Birmingham  
Mindelsohn Way, Edgbaston, Birmingham,  
B15 2GW 
Email: 
 
Katherine.Reeves@uhb.nhs.uk  
UHB Director of 
Communication’s 
contact 
Title / Name: 
Fiona Alexander 
Email: 
fiona.alexander@uhb.nhs.uk  
Phone: 
0121 371 4325 
0 797 386 9365 
 
 
Sponsor’s address 
and contact 
Name of organization: 
University Hospitals Birmingham NHS Foundation Trust 
Name of person: 
Dr Chris Counsel 
Address: 
1st Floor, Education Centre 
Queen Elizabeth Hospital 
Mindelsohn Way, Edgbaston 
Birmingham  
B15 2WB 
Email: 
chris.counsell@uhb.nhs.uk 
Phone: 
01213714185 
Funder 
Collaboration for Leadership in Applied Health Research and Care - West Midlands 
University of Warwick  
Office Room A155 1st Floor 
Health Sciences  
Warwick Medical School  
University of Warwick Coventry  
CV4 7AJ 
ClinicalTrials.gov 
Number 
ClinicalTrials.gov Identifier: NCT03637036  
Design 
Randomized Controlled Trial. 
Participants randomized in equal proportions, stratified by site and job role 
Participants 
University Hospitals Birmingham NHS Foundation Trust staff eligible for the seasonal influenza 
vaccination 
Sample size 
Up to 18,000 
Treatment duration 
About 2-min 
Project duration 
5 months   
October 2018 to February 2019 
 

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Gantt Chart. 
Responsibility of:  
University of Birmingham 
(UofB) 
University of Warwick (UofW) 
UofW and UHB 
 
Stage 1 
 
Sep 
Oct 
Nov 
Dec 
Jan 
Feb 
Mar 
Randomize participants 
to receive different 
letter types 
UHB’s Clinical Business Development Lead will create and send a data file to UHB’s statistician that identifies each 
front line staff member, their worksite, and their job role. 
  
  
  
  
  
 
 
 
UHB’s statistician will randomize staff (stratified by worksite and job role) to groups that receive different letter 
types. 
 
 
 
 
 
 
 
Disseminate letters 
UHB’s communications team will disseminate the reminders according to the randomization schedule. 
  
  
  
  
  
 
 
 
UHB Occupational Health Department will monitor vaccine uptake as per reporting protocols already in place. 
 
 
 
 
 
 
 
Retrieve data 
UHB’s Clinical Business Development Lead will create a data file to send UHB’s statistician that describes: (1) the 
date each participant was vaccinated or no date – up to the 4th of January, (2) whether each participant indicated 
refusal to vaccinate, (3) whether each participant indicated receiving the vaccination elsewhere, and each 
participant’s (4) group-assignment, (5) gender, (6) site, (7) job role.  
  
  
  
  
  
 
 
Analyze data 
UHB’s statistician will analyze the data. 
  
  
  
  
  
 
 
Write-up results 
UHB’s statistician and UofW’s researchers will discuss the analyses interpret the findings. 
 
 
 
 
 
 
 
Write-up full reports 
UofW’s researchers will write-up the project for publication. 
  
  
  
  
  
 
 
 
 

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Approvals being sought to conduct this study.  
The decision as to whether the present study requires NHS-REC approval was decided using the Health 
Research Authority’s tools: “Is my study research?” 1 and “Do I need NHS-REC approval?”2 The outcomes 
provided by these tools are described in Table 1. 
 
Table 1.  
Is my study reseach? 
Yes 
Do I need NHS-REC approval? 
No but may need other approvals, e.g., HRA and potentially site approvals. 
 
Summary of study. (limit 300 words) 
Seasonal vaccination against influenza is recommended for NHS staff.3,4 To increase vaccination rates, NHS 
England put forth a Commissioning for Quality and Innovation goal for the 2018/2019 season of 75%.5 
University Hospitals Birmingham NHS Foundation Trust (UHB) wants its vaccination rate to surpass this 
target. Since staff get infected outside of the hospital and from patients staff vaccination does not provide 
significant ‘herd immunity’ 
 
To reach past targets, every September UHB already invites staff to take up the vaccination, and regularly 
reminds staff that have not yet vaccinated to do so. The current protocol describes a randomized controlled 
trial (RCT) in which staff will be sent a different letter when first invited to receive vaccination, and we will 
compare the proportion of staff that go on to vaccinate after receiving each type of letter.. 
 
To conduct the RCT the research team will design  four letter styles.  One factor will emphasize an authority 
figure inviting staff to vaccinate (the Chief Executive, who is also a doctor). The other factor will emphasize 
a competitive social norm describing  vaccination rates in peer hospitals, including Addenbrooke’s, 
Cambridge University Hospitals (which has exemplary rates) see appendix A and across American hospitals 
(which also have high rates).  Letters will be sent to staff in the last week in September by UHB’s 
communications team and they will be disseminated in a randomized fashion.  
 
The UoW’s role in this study is to advise the study’s design and write-up the project for publication. UHB 
will approve the reminders, send the reminders, retrieve the data, and analyse the data. No individual-level 
data will be transferred across organizations. All individual-level data will be managed by authorized UHB 
employees, e.g., a UHB statistician will randomize staff to receive different reminders and analyze the data, 
and UHB’s communication team to disseminate the reminders.  
 
 

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Questions. 
 
Data/Outcomes. 
Analyses. 
Primary: 
Will the content of different 
wording on the letters 
requesting NHS staff to 
receive the seasonal 
influenza vaccination affect 
the rate at which those staff 
are vaccinated? 
 
Staff IDs- this is needed to randomize and send 
letters-Will be deleted after data collection ceases 
 
Staff Name-this is needed to address letters, e.g., 
“Dear [name]” -Will be deleted after data collection 
ceases 
 
Group Number (e.g., 0=letter version one, 1=letter 
version two, 2=) 
 
 Date of Vaccination at Trust (DD-MM-YYYY, or 
blank if the vaccination was never received), 
 
Indicating Refusal to take up the vaccination (0=No, 
1=Yes),  
 
Indicating Vaccinating at non-Trust Location, e.g., 
general practice  (0=No, 1=Yes) 
 
The primary analysis will compare the proportions of 
staff that take up the vaccination in each group, where 
each group receives a different letter. The rates of 
vaccination will be analyzed with a binary logistic 
regression model including an interaction term and the 
two main effects. While all forms of wording will 
encourage uptake, we hypothesise that some will work 
better than others. 
Secondary: Will the effect sizes vary 
across different 
demographics? 
There are no secondary outcome measures, but 
information related to the participants’ worksite, job role 
and gender will be used as predictors in the secondary 
analyses.  
 
Worksite (0=Queen Elizabeth, 1=Heartlands, 
2=Solihull, 3=Good Hope),  
 
Job role (1=Doctor, 2=Nurse, 3=Other-frontline), 
4=Other-non-frontline), 
 
Gender (0=Female, 1=Male, 2=Not indicated). 
The secondary analysis will look for differences in the 
letter wording effectiveness related to sub-group 
demographics, i.e., worksite, job roles, and gender. 
 
 
 
Data retrieval will be facilitated by UHB’s Clinical 
Business Development Lead from UHB's MyFluJab 
database, and from Occupational Health data systems.  
 
Analyses will be conducted by a UHB statistician 
according to UHB’s secure protocols.   
 
 
 
 

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Summary of main issues. 
No significant ethical, legal, or management issues arise from this study.  
 
The largest risk of this study is the opportunity for NHS staff data to be leaked. To minimize this risk, 
no individual-level data will be transferred across organizations. Rather all data will be retrieved and 
analyzed by authorized UHB staff.  
 
 
Scientific Justification.  
This research is worth doing because current vaccination rates among NHS staff remain lower than 
desired. The variation among NHS trusts’ vaccination rates (from less than 40% to more than 80%)6 
suggests that some trusts’ may doing something better. Unfortunately, reviews of past data do not 
easily indicate malleable factors as to why the rates differ. The current study will examine one 
malleable factor that may affect uptake rates, i.e., the content of letters asking staff to vaccinate. 
 
 
Design and methodology. 
Null Hypothesis:  
All the letters will similarly influence the rate at which staff take up the vaccination. 
Alt Hypothesis:  
The letters will differently influence the rate at which staff take up the vaccination.  
 
The RCT method was selected, because it is the most robust method through which to make causal 
inferences. The RCT method is feasible, because UHB already monitors whether each staff member 
receives the vaccination.    
 
There will be no ‘no-treatment’ control group. All letters will non-coercively invite NHS staff to take 
up the vaccination, though we expect some reminders to work better than others.  
 
Letter wordings are given Appendix A. One factor will emphasize an authority figure inviting staff to 
vaccinate. The other factor will emphasize a competitive social norm describing peer hospital 
performance. Letters will be sent both by e-mail and through the internal post. 
 
UHB’s Clinical Business Development Lead will send UHB's statistician a data file in mid-September 
containing information about staff who should be invited to have a vaccination: 
(1) IDs-needed to randomize at an individual level  
(2) Staff Name-needed to address reminders, e.g., “Dear [name]” 
(3) Worksites-needed to stratify randomization, and  
(4) Job Roles-needed to stratify randomization.  
 
We expect this file to include  up to 18,000 NHS staff members, and this number is more than 
sufficient for our primary comparison. UHB's statistician will randomize these staff to receive one of 
the letters and then will help UHB's communications team to disseminate the letters according to the 
randomized schedule.  
 
In January UHB's Clinical Business Development Lead will send UHB’s statistician a data file 
describing whether those staff randomized to receive a letter went on to get vaccinated by the 4th of 
January. The data will contain information describing each staff member’s:  
(1) ID,  
(2) Worksite,  
(3) Job Role,  
(4) Gender,  
(5) Group,  
(6) Date vaccination was received at Trust, if ever,  

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(7) Whether the staff member indicated not intending to take up vaccination, and  
(8) Whether the staff member has indicated receiving the vaccination from another source, 
e.g., general practice.  
 
UHB's statistician will analyze the data and then interpret the findings with UoW’s researchers. 
UoW’s researchers will write-up the findings for publication.  
 
 
Randomization Process. 
Yes.  
 
Each NHS staff member will be randomized to one of the available groups, and each group will 
receive a different letter.  
 
The randomization will be stratified by worksite and job role. The random number function RAND in 
Microsoft Excel will be used to generate random numbers and within each of the 12 strata the 25% of 
staff with the lowest values will be assigned to group 1, etc.   
 
 
Participants. 
Samples Size: 
Up to 18,000 
 
How was the 
sample size 
decided? 
UHB aims to vaccinate approximately 18,000 NHS staff. The following sample-size 
calculations were performed (using an assumed alpha rate of 0.05 and a beta of 0.8) 
for a binary logistic regression model including an interaction term as well as two 
main effects. 
 
To detect an interaction such that the uptake is 40% in three of the groups and 50% 
in the other group will require a sample-size of at least 750 per group. Thus, we have 
a sufficient sample size to find a much smaller difference overall and differences in 
sub-groups. 
 
Inclusion:  
All UHB staff eligible for the seasonal influenza vaccination are eligible for this 
study.   
 
Exclusion: 
No patients will be excluded. 
 
Duration in 
study:  
NHS staff will be monitored in this study for approximately 4 months, i.e., from the 
date the letter is disseminated (near the end of September) through the 4th of January 
2019. Note that our observations only involve recording when NHS staff receive the 
vaccination, and such data are already routinely recorded. 
 
Risks:  
There are no risks beyond standard practice. The largest risk regards NHS staff’s 
personal data being leaked. To minimize the risk of data leaks, no data will be 
transferred across organizations. Rather data will be retrieved and analyzed by 
authorized UHB staff according to UHB's standard protocols. 
 
Benefits:  
NHS staff participants will contribute to our understanding of what types of 
reminders more effectively motivate NHS staff to vaccinate.   
 
 
 

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Allocation 
Analysis 
Randomized (expected n= 18,000) 
Stratified by worksite and job role 
Allocated to reminder 
version four 
(expected n= 4,500) 
Analysed  
(expected n= 4,500) 
 
Allocated to reminder 
version one 
(expected n= 4,500) 
Allocated to reminder 
version three 
(expected n= 4,500) 
Allocated to reminder 
version two 
(expected n= 4,500) 
Analysed  
(expected n= 4,500) 
 
Analysed  
(expected n= 4,500) 
 
Analysed  
(expected n= 4,500) 
 
Assessed for eligibility 
(Expect n= 18,000 NHS Staff) 

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Participant Identification/Recruitment. 
How will potential participants, 
records or samples be identified? Who 
will carry this out and what resources 
will be used? 
 
UHB’s Clinical Business Development Lead will identify NHS 
staff members who should be vaccinated using regularly 
collected information in UHB’s Information Systems. 
 
We will be using the IT Flu Application developed in-house by 
UHB’s Information Technology team from which UHB can 
extract staff level data indicating who has been vaccinated and 
their role. We will use similar systems at the other sites  
  
Will the identification of potential 
participants involve reviewing or 
screening the identifiable personal 
information of patients, service users 
or any other person? 
 
Yes. 
 
The identification of potential NHS staff members will involve 
reviewing the identifiable personal information. 
 
UHB’s Clinical Business Development Lead will identify NHS 
staff members who are eligible to be vaccinated using regularly 
collected information in UHB’s Information Systems.  
 
Describe what measures will be taken 
to ensure there is no breach of any duty 
of confidentiality owed to patients, 
service users or any other person in the 
process of identifying potential 
participants. 
 
To minimize the risk of data leaks, no data will be transferred 
across organizations. Rather data will retrieved and analyzed by 
authorized UHB staff according to UHB's standard protocols.  
 
 
Will researchers or individuals other 
than the direct care team have access 
to identifiable personal information of 
any potential participants? 
 
No 
Will any participants be recruited by 
publicity through posters, leaflets, 
adverts or websites? 
 
No 
How and by whom will potential 
participants first be approached? 
 
NHS staff participants will not be explicitly recruited, because 
their part in this study will be incidental as part of their normal 
staff experience. Recall that UHB already reminds staff to 
receive the vaccination and monitors whether those staff are 
vaccinated. 
   
Will you obtain informed consent from 
or on behalf of research participants? 
 
No.  
 
As stated above (for the How and by whom question), 
participants’ part in this study will be incidental.  
 
Will you recruit any participants who 
are involved in current research or 
have recently been involved in any 
research prior to recruitment? 
 
Not known.  
 
No steps will be taken to find out whether the NHS staff are 
involved in other research, because (regardless of their 
involvement in other research) all staff are regularly reminded to 

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take up the seasonal influenza vaccination. 
 
Will you be undertaking any of the 
following activities at any stage 
(including in the identification of 
potential participants)? 
 
Participants in this study are NHS Staff. The data collected are 
already regularly gathered and analyzed by UHB administrators 
for reporting.  
 
 
Information about the data storage. 
Please describe the physical security 
arrangements for storage of personal 
data during the study? 
 
The data will be encrypted during transfer between 
authorized UHB staff over UHB network connections. No 
data will transfer outside of UHB. 
 
The data will be stored by UBS’s statistician during the study 
in password protected files according to UHB’s standard 
protocols. 
  
How will you ensure the 
confidentiality of personal data? 
No personal data will be stored after the data retrieval has 
ceased. Rather all personal data will be deleted and replaced 
with an anonymous ID. 
 
Who will have access to participants' 
personal data during the study? 
 
Only authorized UHB will have access to that data during the 
study. 
 
Where will the data generated by the 
study be analyzed and by whom? 
 
The data files used during this study will be created by 
UHB’s Clinical Business Development Lead at UHB 
according to UHB’s standard protocols.  
 
The data will be analyzed by a UHB statistician according to 
UHB’s standard protocols. 
 
Who will have control of and act as 
the custodian for the data generated 
by the study? 
The data custodian will be a UHB statistician named in this 
protocol. If this UHB statistician is not able to fulfill this 
duty, an amendment will be submitted to replace the named 
statistician. The UHB statistician will conduct all analyses 
and no data will be transferred outside UHB. 
 
For how long will you store research 
data generated by the study? 
 
10-years  
 
How long will personal data be 
stored or accessed after the study has 
ended? 
 
No personal data will be stored after the study ends. 
Please give details of the long term 
arrangements for storage of research 
data after the study has ended.  
 
No identifiable data will be stored after data collection has 
ceased.  
 
The non-identifiable data will be stored on secure UHB 
servers in a password protected file. The statistician named 
on this protocol will have access to the data and will allow 
access to the data to regulators if requested. 

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Will you inform participants of the results? 
The findings will be shared through the UHB’s regular communication channels, e.g., the Trust’s 
newsletter and all staff briefing. 
 
 
Funder Responsibility. 
CLAHRC money will be made available to cover 2.5% of Prof Richard Lilford’s FTE salary over the 
duration of this project, i.e., approximately 4 hours per month. CLAHRC money will also be made 
available to pay for the dissemination materials if necessary, e.g., publication cost. 
 
 
Conflicts of interest 
Neither the participants nor the research team members will receive any payments (beyond typical 
salary) or other reimbursements for their part in this study.  
 
 
Study Management. 
The Study Management/Steering Committee will meet at the beginning of the study (October) the 
middle (December) and the end (March) to discuss the study and manage any concerns. Members are 
as follows:  
 
Prof Richard Lilford 
 
Dr Kelly Ann Schmidtke 
 
Prof Ivo Vlaev 
 
Mr Lawrence Tallon   
 
Peter Nightingale 
 
Additional people may join the meeting upon as necessary to address issues as they arise.  
 
Dissemination outside of UHB Authorship.  
The findings will be written-up for an academic journal and may be presented at 
conferences/workshops. Any publication/presentation will acknowledge the funder’s support. 
 
All protocol contributors will be eligible for authorship. The author order and the addition of authors 
will be determined by the chief investigator.  
 
 
Approvals to conduct. 
The study described in this protocol will not be initiated before the protocol has received 
approval/favorable opinion from the Health Research Authority (HRA) and participating sites. If 
HRA deems that this study requires a sponsor, any consideration for amendments will immediately be 
given to the sponsor with a detailed justification. The sponsor will then decide whether such 
amendments constitute a non-substantial or substantial amendments. Amendments that require HRA 
approval will not be instituted until they received approval/favorable opinion from the HRA. Minor 
amendments may be implemented immediately, and the HRA will be informed. 
 
The study will be conducted in accordance with the ethical principles that have their origin in the 
Declaration of Helsinki, 1996,7 the principles of Good Clinical Practice,8 and the Department of 
Health Research Governance Framework for Health and Social Care, 2005.9 
 
 

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Appendix 1.  
 
On the next page are four letter formats. One factor is the presence of an authority figure giving staff 
access to the vaccinations. The authority figure is  Dr David Rosser, the Chief Executive and also a 
medical doctor.  The other factor is the presence of descriptive norms describing the proportions of 
staff that have been vaccinated in peer hospitals.   
 
Within the examples the highlighted areas indicate where these two factors are active.  
GREEN = authority factor.  
YELLOW = norms factor.  
 
 
 
 
 
 
 
 

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Emailed Letters. 
 
Letter one 
Dear colleague,  
You are invited to take up your free flu jab this season to reduce your risk, and your patients' 
risk, of getting the flu. 
Find out how to get your jab at the Trust, please visit the [________] part of the Intranet or ask your line 
manager.  
We appreciate your support in keeping colleagues and patients safe,  
 
Occupational; Health Department 
 
Letter two 
 
Dear name,  
I am inviting you to take up your free flu jab this season to reduce your risk, and your 
patients' risk, of getting the flu. 
Last winter, the national expectation was for at least 70% of frontline staff to be vaccinated 
against seasonal flu. That was achieved at QEHB, with 71.6%, and at Heartlands, Good 
Hope and Solihull with 73.5%. This year, the national expectation is for 75% of frontline staff 
to be vaccinated.  
However, we want UHB to be amongst the very best performers of similar hospitals, so that 
we maximise protection for our staff and patients. We know it is entirely achievable, with 
your support, for us to reach or surpass  the levels of some of the  best performers from last 
year: 
Royal Liverpool & Broadgreen                    86.9% of frontline staff vaccinated 
Cambridge University Hospitals                 
84.3%  
Birmingham Children’s Hospital 
 
82.1% 
Leeds Teaching Hospitals                             80.8% 
Guy’s and St Thomas’s                                 79.9% 
In the United States 92% of hospital staff receive flu vaccination. 
Find out how to get your jab at the Trust, please visit the [________] part of the Intranet or ask your line 
manager.  
I appreciate your support in keeping colleagues and patients safe,  
 
Kind regards 
Occupational Health Department 
 

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Letter three 
Dear colleague,  
You are invited to take up your free flu jab this season to reduce your risk, and your patients' 
risk, of getting the flu. 
Last winter, the national expectation was for at least 70% of frontline staff to be vaccinated 
against seasonal flu. That was achieved at QEHB, with 71.6%, and at Heartlands, Good 
Hope and Solihull with 73.5%. This year, the national expectation is for 75% of frontline staff 
to be vaccinated.  
However, we want UHB to be amongst the very best performers of similar hospitals, so that 
we maximise protection for our staff and patients. We know it is entirely achievable, with 
your support, for us to reach or surpass  the levels of some of the  best performers from last 
year: 
Royal Liverpool & Broadgreen                    86.9% of frontline staff vaccinated 
Cambridge University Hospitals                 
84.3%  
Birmingham Children’s Hospital 
 
82.1% 
Leeds Teaching Hospitals                             80.8% 
Guy’s and St Thomas’s                                 79.9% 
In the United States 92% of hospital staff receive flu vaccination. 
Find out how to get your jab at the Trust, please visit the [________] part of the Intranet or ask your line 
manager.  
We appreciate your support in keeping colleagues and patients safe,  
 
Occupational; Health Department 
 
 
Letter four  
Dear name,  
I am inviting you to take up your free flu jab this season to reduce your risk, and your 
patients' risk, of getting the flu. 
Last winter, the national expectation was for at least 70% of frontline staff to be vaccinated 
against seasonal flu. That was achieved at QEHB, with 71.6%, and at Heartlands, Good 
Hope and Solihull with 73.5%. This year, the national expectation is for 75% of frontline staff 
to be vaccinated.  
However, we want UHB to be amongst the very best performers of similar hospitals, so that 
we maximise protection for our staff and patients. We know it is entirely achievable, with 

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your support, for us to reach or surpass  the levels of some of the  best performers from last 
year: 
Royal Liverpool & Broadgreen                    86.9% of frontline staff vaccinated 
Cambridge University Hospitals                 
84.3%  
Birmingham Children’s Hospital 
 
82.1% 
Leeds Teaching Hospitals                             80.8% 
Guy’s and St Thomas’s                                 79.9% 
In the United States 92% of hospital staff receive flu vaccination. 
Find out how to get your jab at the Trust, please visit the [________] part of the Intranet or ask your line 
manager.  
I appreciate your support in keeping colleagues and patients safe,  
 
Kind regards 
 
Dr Dave Rosser 
Chief Executive 
 
References.  
                                                          
1 http://www.hra-decisiontools.org.uk/research/redirect.html 
2 http://www.hra-decisiontools.org.uk/ethics/  
3 England Public Health. (2016). Healthcare worker vaccination: Clinical evidence. London: PHE, 2016. 
http://www.nhsemployers.org/~/media/Employers/Publications/Flu%20Fighter/flu%20fighter%20clinical%20ev
idence%20Aug%202016.pdf [Accessed 20/05/2018 
4 Pereira, M., Williams, S., Restrick, L., Cuninon, P., Hopkinson, N. S., et al. (2017). Healthcare worker 
influenza vaccination and sickness absence: an ecological study, Clinical Medicine, 17, 484-489.  
5 NHS England.  (2018). NHS staff health & wellbeing: CQUIN 2017-19 Indicator 1 Implementation Support. 
https://www.england.nhs.uk/wp-content/uploads/2018/05/staff-health-wellbeing-cquin-2017-19-
implementation-support.pdf [Accessed 20/05/2018] 
6 Public Health England. (2018). Seasonal influenza vaccine uptake amongst frontline healthcare workers 
(HCWs) in England. December Survey 2017/18. 
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/710531/Seaso
nal_influenza_vaccine_uptake_HCWs_winter_season_2017_to_2018.pdf  
7 https://www.wma.net/wp-content/uploads/2016/11/DoH-Oct1996.pdf  
8 https://www.hra.nhs.uk/planning-and-improving-research/policies-standards-
legislation/good-clinical-practice/  
9https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_dat
a/file/139565/dh_4122427.pdf  

1 
 
Statistical Analysis Plan 
 
Version: 1  
Date: 21-December-2018 
Trial Title: An improvement project to evaluate the effectiveness of different reminders designed to increase the 
University Hospitals Birmingham NHS Foundation Trust’s staff uptake of the seasonal influenza vaccine.  
Authors:  
• 
Schmidtke, Kelly (Kelly.Schmidtke@wbs.ac.uk, Research Fellow, University of Warwick) 
• 
Nightingale, Peter (peter.nightingale@uhb.nhs.uk, Statistician, University Hospital Birmingham NHS 
Foundation Trust) 
• 
Reeves, Katharine (katharine.reeves@uhb.nhs.uk, Statistical Intelligence Analyst, University Hospital 
Birmingham NHS Foundation Trust) 
• 
Lilford, Richard (r.j.lilford@warwick.ac.uk, Professor, University of Warwick) 
 
 
1. INTRODUCTION  
 
The present Statistical Analysis Plan extends the outcome analyses previously stated in the protocol version 2.0 
(ClinicalTrials.gov Identifier: NCT03637036) to clarify how we will handle more analyses and a protocol deviation 
that occurred during the randomization process.  
 
 
2. DATA  
 
Data collection is described in protocol (version 2, page 5). However, deviations from the protocol resulted in 
modifications to some of the data we will have available for the analyses. Table 1 describes the data contained in the 
data file.  
 
The first deviation occurred because of the four worksites originally planned to be in the trial, three could not take 
part. This left one worksite in the trial, i.e. Queen Elizabeth Hospital.  
 
The second deviation affects our plans for sub-group analyses. This occurred because the trust records describe job 
roles differently than stated in the protocol. So instead of the job roles stated in the protocol, staff were stratified by 
two Employment-Types and four Job-Types. 
 
The third deviation occurred as 898 (10.6%) of the hospital’s 8438 staff randomized were allocated to a fifth, no-
letter, control group. The remaining 7,540 staff were randomized to the planned four groups in equal numbers (i.e., 
1885 participants to each of four groups). We will analyse data in the four groups per the original protocol and this 
will be the primary analysis. However, we will also carry out a subsidiary analysis to compare the results of this no-
letter control group to the letter groups, as described in the below section titled ‘Supplementary Analysis’.  
 
 
 
 

2 
 
Table 1. Data in the project analysis file 
Type 
Name 
Codes 
Intervention 
Group Number 
0 = Standard, 
1 = Social Norms, 
2 = Authority 
3 = Combined, and 
4 = No Letter Control 
 
Demographics 
Gender 
0 = Female, and 
1 = Male 
 
 
 
Type of Employment 
0 = Bank, and 
1 = Substantive 
 
 
Job Type 
0 = Healthcare assistants and other support staff, 
1 = Medical and dental staff, 
2 = Nursing, midwifery and health visiting staff, and 
3 = Scientific, therapeutic and technical staff 
 
(for the analyses, groups 0 and 3 will be combined) 
Primary 
Outcome 
Date of vaccination at 
Trust 
DD-MM-YYYY, or 
blank if the vaccination was never received 
 
Other 
outcomes 
(formally self-
reported) 
Refusal to take up the 
Vaccination 
0 = No, and 
1 = Yes 
 
 
Vaccinating at a non-
trust location 
0 = No, and 
1 = Yes 
 
 
 
3. ANALYSIS OBJECTIVES  
• 
Objective 1 is to assess the effects of the two intervention types (Social Norms and Authority) and any 
interaction effect of these interventions on the on-site vaccination rates by the end of the trial, i.e. 4th of 
January 2019.  
• 
Objective 2 is to assess the effects of the interventions on subgroups of the study. We are most interested in 
comparisons across the above stated three job types, though we will also compare the effects across genders. 
We will not examine the type of employment because the bank sub-group is small, but we will report the 
proportion of staff taking up the vaccine in this subgroup.  
• 
Objective 3 is to assess cumulative rates of vaccinations across each group by week from the beginning to 
the end of the study period.  
 
 
4. GENERAL ANALYSIS CONVENTIONS  
 
All descriptive statistics will be reported with 95% confidence intervals, and statistical analyses will be two-sided. 
 
 

3 
 
5. ANALYSES 
 
Our primary analysis will be a binary logistic regression analysis with on-site vaccination (0=No, 1=Yes) as the 
outcome variable and the two main intervention effects, Social Norms (0=No, 1=Yes) and Authority (0=No, 1=Yes), 
and the interaction effect as explanatory variables. The no-letter control group will not be considered in this primary 
analysis.  
 
Descriptively, a table (Table 2), will be created displaying the staff vaccination uptake for each group with the 
corresponding exact binomial 95% confidence interval.  
 
Table 2. Staff onsite vaccination rates 
 
Standard 
Group 
 
Norms 
Group 
 
Authority 
Group 
Combination 
Group 
 
 
n 
Uptake 
Proportion 
(95% 
Confidence 
Interval) 
n 
Uptake 
Proportion 
(95% 
Confidence 
Interval) 
n 
Uptake 
Proportion 
(95% 
Confidence 
Interval) 
n 
Uptake 
Proportion 
(95% 
Confidence 
Interval) 
Total 
# 
0.__  
(0._, 0.__) 
# 
0.__  
(0._, 0.__) 
# 
0.__  
(0._, 0.__) 
# 
0.__  
(0._, 0.__) 
Gender 
 
 
 
 
 
 
 
 
Female 
# 
0.__  
(0._, 0.__) 
# 
0.__  
(0._, 0.__) 
# 
0.__  
(0._, 0.__) 
# 
0.__  
(0._, 0.__) 
Male 
# 
0.__  
(0._, 0.__) 
# 
0.__  
(0._, 0.__) 
# 
0.__  
(0._, 0.__) 
# 
0.__  
(0._, 0.__) 
Employment-Type 
 
 
 
 
 
 
 
 
Bank 
# 
0.__  
(0._, 0.__) 
# 
0.__  
(0._, 0.__) 
# 
0.__  
(0._, 0.__) 
# 
0.__  
(0._, 0.__) 
Substantive 
# 
0.__  
(0._, 0.__) 
# 
0.__  
(0._, 0.__) 
# 
0.__  
(0._, 0.__) 
# 
0.__  
(0._, 0.__) 
Job-Type 
 
 
 
 
 
 
 
 
Medical and 
dental staff 
 
# 
0.__  
(0._, 0.__) 
# 
0.__  
(0._, 0.__) 
# 
0.__  
(0._, 0.__) 
# 
0.__  
(0._, 0.__) 
Nursing, 
midwifery and 
health visiting 
staff 
# 
0.__  
(0._, 0.__) 
# 
0.__  
(0._, 0.__) 
# 
0.__  
(0._, 0.__) 
# 
0.__  
(0._, 0.__) 
Healthcare 
assistants, other 
support staff 
Scientific, 
therapeutic and 
technical staff 
# 
0.__  
(0._, 0.__) 
# 
0.__  
(0._, 0.__) 
# 
0.__  
(0._, 0.__) 
# 
0.__  
(0._, 0.__) 
 
 
In addition to the primary analysis, a binary logistic regression analysis will be used to predict staff on-site 
vaccination rate (0 = No, 1= Yes) using all of the following variables: the two main intervention effects 
(Social Norms and Authority) and their interaction effect, Employment-type (0=Bank, 1=Substantive), Job-
Type (1=Medical and dental staff, 2=Nursing, midwifery and health visiting staff, and 4= a combined group 
composed of Healthcare assistants, other support staff and Scientific, therapeutic and technical staff), Gender 
(0=Female, 1=Male) and any of the following interactions that are significant: Social Norms x Job type; 
Social Norms x Gender; Authority x Job type; Authority x Gender; Social Norms x Authority x Job type; and 
Social Norms x Authority x Gender. (If either of the three-way interactions is included, all the constituent two-
way interactions will also be included.) 
 
 

4 
 
 
To achieve Objective 3, secondary analysis 
will assess the effects of the interventions 
over time, to examine the hypothesis that the 
benefits of the interventions may be greater 
nearer the beginning of the trial than nearer 
the end.  
 
This effect will initially be assessed by 
visually examining a time-series chart, such 
as represented in Figure 1. We will also 
estimate the time to vaccination within each 
group to reach 70% vaccination. To do so, 
Kaplan–Meier rates of survival (i.e. non-
vaccination) will be derived, with confidence 
intervals based on the exponential 
Greenwood formulation of the standard error.  
We selected 70% because this was the 
vaccination target and was achieve by the 
hospital over the 2017-2018 vaccination 
season. If a rate of 70% is not achieved in all 
four groups we will estimate the time to reach 
10m%, where m is the largest integer such 
that the rate in all four groups is at least 
10m%. The proportional hazards assumption 
will be tested by including interactions of 
each term (the two main intervention effects 
and their interaction) with log of time since 
00:00 on 4th October 2018 in a Cox 
proportional hazards model. 
Figure 1. Time series chart 
 
 
 
 
 
6. COLLECTION AND ENDPOINTS 
 
The outcome data are being collected in real-time and stored by UHB’s team (not the research team) between the day 
the letters were sent out, the 4th of October 2018, until data-lock at 12:00 AM on the 4th of January 2019. The 
research team’s statistician, Dr Peter Nightingale, will receive the outcome data on the 4th of January 2019 between 
8:00 and 13:00 Greenwich Mean Time.  
 
 
 
7. DATA NOT CONSIDERED IN STATISTICAL ANALYSES 
 
The other outcomes (refusal to vaccinate and vaccinating at another site) will not be considered in statistical analyses 
for two reasons. First, participants are required to self-report this information through an online system that was not 
encouraged by our interventions. Second, these numbers are typically too small to impact our planned analyses, i.e. 
typically less than 2.5% of participants.  
 
These outcomes will be reported descriptively for each group in the final report. For example: Of the total number of 
participants ## refused to take up the vaccination, of which ## were sent the standard letter, ## were sent the social 
norms letter, ## were sent the authority letter, and ## were sent the combined letter.  
 
0,00
0,10
0,20
0,30
0,40
0,50
0,60
0,70
0,80
0,90
1,00
Proportion Vaccinated
Cumulative Proportion of Staff Vaccinating on site
by Group
Error bars represent 95% confidence intervals
Standard
Social Norms
Authority
Combined

5 
 
 
8. HANDLING OF MISSING VALUES  
 
The outcome data will not have missing values as onsite staff vaccinations, the primary outcome, are all recorded 
routinely at the time of the vaccination. The denominator will comprise all front-line staff working in the hospital on 
the day of randomization, the 24th of September 2018. Self-reported refusals and self-reported vaccinations at 
another site are not the primary outcome data but are recorded on the system when available.  
 
  
 
No attempt will be made to include staff joining the hospital after the randomization on the 24th of September 2018.  
 
 
9. SUPPLEMENTARY ANALYSIS  
 
Unknown to the University team who registered the trial and obtained ethical approval, for operational reasons the 
hospital members of the research team created a fifth group of participants who were sent no letter (n = 898).  
 
A further analysis will be performed to utilize data collected in response to this protocol deviation. Using the 
information collected because of this deviation, we will compare the uptake of staff in this group to the amalgamation of 
those who were sent any of the four letters. This will be done by comparing the vaccination rates in these two groups 
using Fisher’s exact test and also by binary logistic regression analysis with the outcome on-site vaccination (0 = No, 1= 
Yes) and the following explanatory variables: whether letter sent (0 = No, 1= Yes), Employment-type (0=Bank, 
1=Substantive), Job-Type (1=Medical and dental staff, 2=Nursing, midwifery and health visiting staff, and 4= a combined 
group composed of Healthcare assistants, other support staff and Scientific, therapeutic and technical staff), Gender 
(0=Female, 1=Male) and any of the following interactions that are significant: Social Norms x Job type; Social Norms x 
Gender; Authority x Job type; Authority x Gender; Social Norms x Authority x Job type; and Social Norms x Authority x 
Gender. (If either of the three-way interactions is included, all the constituent two-way interactions will also be included.)