International media coverage for research linking flu vaccine with reduced risk of stroke

ipvastia_wordcloudA study from CaHRU, ‘Influenza vaccination and risk of stroke: self-controlled case-series study‘, recently published in the journal Vaccine, received international coverage in news media. The study of almost 18,000 patients with stroke looked at data from general practices in England using a self-controlled case series analysis, and showed that the risk of suffering a stroke is significantly reduced for up to two months after receiving a flu vaccine.

ipvastia_teamThe lead author was Dr Zahid Asghar, who conducted the research together with Prof Niro Siriwardena (both from CaHRU) and Dr Carol Coupland (from Nottingham University School of Community Health Sciences). This is the fourth in a series of studies over the past 10 years looking at the link between flu vaccination and reduction in risk of heart attack and stroke.

ipvastia_mediamapThe coverage included articles in The Times, Sun and Scottish Sun newspapers, BBC television and radio and online media outlets in the US, Middle East, Asia, Australasia and South America. The team are now designing future studies to explore the potential for flu vaccination to reduce risk of heart attack and stroke.

New study from CaHRU shows link between flu vaccination and reduction in stroke

ipvastia_team2The latest study from CaHRU is published online in Vaccine this month. The study, ‘Influenza vaccine and risk of stroke: self-controlled case series study‘, was co-authored by Dr Zahid Asghar and Professor Niro Siriwardena from CaHRU together with Carol Coupland, professor of medical statistics at Nottingham University. The study used a self-controlled case series design with data from the General Practice Research Database (GPRD) on adult patients aged 18 years and above with fatal or non-fatal stroke during 8 years from September 2001 to May 2009.

h1n1Statistical analysis was used to compute incidence of stroke after flu vaccination compared with incidence during a baseline period in almost 18000 people who received one or more influenza vaccinations and experienced a first stroke during the observation period. The incidence (incidence rate ratio: IRR) of stroke was significantly reduced in the first 59 days following flu vaccination compared with the baseline period. We found reductions in stroke incidence of 55% in the first 1–3 days after vaccination, 36% at 4–7 days, 30% at 8–14 days, 24% at 15–28 days and 17% at 29–59 days after vaccination. Early vaccination between 1 September and 15 November was associated with a greater reduction in incidence of stroke compared to later vaccination given after mid-November.

Flu vaccination was associated with a reduction in incidence of stroke, which confirms findings from previous studies showing possible protective effects of flu vaccination for both heart attack and stroke. This association needs further confirmation with experimental (randomised controlled) trials.

Ambulance Services Cardiovascular Quality Initiative resources now online

ascqilogoThe new Ambulance Services Cardiovascular Quality Initiative (ASCQI) website was launched this month. The website describes how the ASCQI project, funded by the Health Foundation’s Closing the Gap in Clinical Communities Programme, achieved its aims as the first national quality improvement collaborative involving all English ambulance services.

The aims of ASCQI were to improve ambulance care for heart attack and stroke across England and specifically:

  • To improve the delivery of care bundles for AMI from 43% to over 70% within two years of the project
  • To improve delivery of care bundles for stroke from 83% to over 90% within two years of the project
  • To increase diffusion of quality improvement methods to frontline staff in ambulance services.

EMAS - A&E 5_750As a result of the collaborative nine out of twelve ambulance trusts showed a significant improvement in either the stroke or AMI care bundle, and seven out of twelve showed significant improvements for both AMI and stroke. Performance for the care bundle for AMI increased from 43 percent to 79 percent, and for stroke 83 percent to 96 percent during the two years of the project and these improvements have been maintained. These results were published in the journal Implementation Science. A secondary aim of the initiative was to begin to develop patient reported experience measures (PREMs) for AMI and stroke. Preliminary qualitative work for development of PREMS for ambulance services was published in the EMJ, and this work is being continued by Fiona Togher of CaHRU through a funded doctoral study.

EMAS - A&E 9_750The website includes a range of resources which were used by ambulance services to deliver the improvements that we saw nationally. The work is now helping to inform similar prehospital improvement initiatives in the Middle East and North America and will be featured in a session on key care pathways in a Web and Action webinar series developed by the Institute for Healthcare Improvement, a world leader in healthcare quality improvement based in the United States, starting in March 2015.

Dr Zahid Asghar presents study results on influenza vaccine and reduced risk of stroke in New York

N0013781 Cerebral infarctDr Zahid Asghar recently attended the North American Primary Care Research Group (NAPCRG) conference in New York City to present findings from ‘Influenza vaccination and risk of stroke: self-controlled case-series study’. This was an observational study of investigating the association between influenza vaccination and stroke led by Professor Niro Siriwardena, director of CaHRU, and Dr Carol Coupland, associate professor in statistics at the University of Nottingham.

Zahid@NAPCRG2014_750The study involved analysis of almost 18 thousand cases of stroke over a period of eight years from a general practice database, the Clinical Practice Research Datalink. The investigators found a significant reduction in risk of stroke up to 59 days following vaccination. The work follows publication of a case-control study earlier this year and involving almost 10,000 patients showing a 20% reduction in risk of stroke associated with flu vaccination together with previous studies conducted by Professor Siriwardena and his team showing a reduction in risk of heart attack associated with influenza vaccine.

NY2_750It is not known how influenza vaccination prevents heart attack or stroke. It might be because influenza has been shown to occur two to four weeks before these conditions and may trigger them in a proportion of cases or it might be due to immunological protection from the vaccine. There was worldwide interest in this area of research following the team’s study published in the Canadian Medical Association Journal.

Paramedics’ views on their role in an ambulance based trial of ultra-acute stroke

N0013781 Cerebral infarctNovel treatments for stroke are increasingly being tested and delivered in the ultra-acute period during initial presentation to ambulance services. In the first feasibility trial of nitroglycerin (glyceryl trinitrate) in ultra-acute stroke (RIGHT) there were early indications of improvements in outcomes and disability at three months. The research team was led by Prof Philip Bath and his team at Nottingham University, together with Sandeep Ankolekar, Prof Niro Siriwardena from CaHRU and researchers at East Midlands Ambulance Service NHS Trust.

N0029297 Young man using a nicotine patchA nested qualitative study entitled ‘Views of paramedics on their role in an out-of-hospital ambulance-based trial in ultra-acute stroke: qualitative data from the Rapid Intervention with Glyceryl Trinitrate in Hypertensive Stroke Trial (RIGHT)‘ explored facilitators and barriers to paramedic involvement in clinical trials. The fieldwork was conducted by Dr Sandeep Ankolekar and the team. Barriers to participation included the pressure of the emergency setting, difficulties  obtaining informed consent, institutional support for research, the steep learning curve for research naive staff and relative rarity for individual paramedics of clinical conditions seen, and difficulty in attending training sessions.

N0030773 Paramedic driving an ambulanceSuggestions for improvement included a simple diagnostic tool for stroke, use of assent and proxy consent on behalf of patients (as in the trial), and simpler trial processes.Recruitment became easier with each new randomisation attempt. Paramedics in the study were motivated to participate in research. Treatment of acute stroke in the out-of-hospital environment was feasible, but important barriers needed to be addressed.