Associations between seasonal influenza and heart and lung conditions as well as flare-ups of diabetes have been observed. Currently the data needed to determine whether new influenza vaccines will be value for money is lacking. The data are needed to better understand the how much disease could be prevented by influenza vaccination as well as to plan clinical studies.
This project aims to produce age-specific rates of new events related to heart and lung conditions as well as flare-ups of diabetes events in the English adult CPRD population, and specifically in high-risk groups targeted for influenza vaccination (adults aged ?65; and younger adults with a range of pre-existing health conditions) for a ten-year period (2010/11 2019/20). The rates of these events will be assessed in GP primary care data and hospital data as well as in these data sources combined to help assess any underestimation of events using one dataset alone. This study will determine rates in other high-risk groups recommended for influenza vaccination such as individuals with long term medical conditions. Additionally, this study will describe events according to the season of diagnosis, whether they needed to be admitted overnight to hospital or died and by whether they received an influenza vaccination or not.
Finally, we will estimate the proportion of events which might have been originally caused by an influenza infection by comparing the number of events we see during weeks with more influenza circulation with time periods when less influenza was circulating.
Background and rationale:
Associations between seasonal influenza and cardio-respiratory and exacerbations of diabetes events (CRD) have been observed. Currently the data needed to determine whether new influenza vaccines are cost-effective is lacking. Data are needed to better understand the burden of disease which could be prevented by influenza vaccination as well as to plan clinical studies, and particularly their sample sizes.
Objectives:
Describe the demographics of the adult study population by age, high-risk for influenza conditions and influenza vaccination status
Determine the age-stratified incidence rate of CRD events during and outside influenza season and stratify by:
- other specified high-risk groups,
- seasonality,
- "cardiovascular", "respiratory" or "diabetic" cause
Apply an excess modelling approach to estimate the influenza-attributable proportion of these cases and deaths
Methods:
In this retrospective longitudinal observational cohort study CRD events in England will be described in primary care (CPRD GOLD and CPRD Aurum), secondary care (HES APC), both combined and with deaths from ONS mortality data. The study period is from 2010/11 to 2019/20 with events described as age-stratified incidence rates for each influenza season (1st December to 31st May). Individuals must be aged >/=18 on the first day of each influenza season and will be defined in primary care using READ and SNOMED codes and in secondary care and ONS mortality using ICD10 "I", "J" or "E" codes. The population at risk will be estimated as the CPRD population on the 1st of January at the mid-point of each influenza season (1st December to 31st May the following year). Excess event modelling will be conducted using a modified Serfling-Poisson statistical regression model which uses influenza data as an exposure, after controlling for seasonal and other confounders.
Primary care, hospitalisation and mortality events for:
- Cardio-Vascular: cardiac [total]
Sub-groups: Hypertensive heart disease; Hypertensive heart and renal disease; Myocardial infarction; Subsequent myocardial infarction; Ischaemic cardiomyopathy; Acute pericarditis; Other diseases of pericardium; Acute and subacute endocarditis; Endocarditis and heart valve disorders in diseases classified elsewhere; Acute myocarditis; Myocarditis in diseases classified elsewhere; Cardiomyopathy; Cardiac arrest; Heart failure
- Cardio-Vascular: vascular [total]
Sub-groups: Subarachnoid haemorrhage; Intracerebral haemorrhage; Other nontraumatic intracranial haemorrhage; Cerebral infarction; Stroke, not specified as haemorrhage or infarction; Occlusion and stenosis of precerebral arteries, not resulting in cerebral infarction; Occlusion and stenosis of cerebral arteries, not resulting in cerebral infarction; Other cerebrovascular diseases; Cerebrovascular disorders in diseases classified elsewhere; Sequelae of cerebrovascular disease
- Cardio-Vascular: arrythmia [total]
Sub-groups: Atrial fibrillation and flutter; Other cardiac arrhythmias
- Respiratory [total]
Sub-groups: Influenza and pneumonia; Unspecified chronic bronchitis; Emphysema; Other chronic obstructive pulmonary disease; Asthma; Respiratory failure, not elsewhere classified
- Diabetic exacerbations [total]
Sub-groups: Type 1 diabetes mellitus with ketoacidosis or coma; Type 2 diabetes mellitus with ketoacidosis or coma; Malnutrition-related diabetes with ketoacidosis mellitus or coma; Other specified diabetes mellitus with ketoacidosis or coma; Unspecified diabetes mellitus with ketoacidosis or coma; Other hypoglycaemia
Hypoglycaemia, unspecified; Abnormal glucose tolerance test
All-cause mortality
All-cause hospitalisation
Rebecca Ghosh - Chief Investigator - CPRD
Rebecca Ghosh - Corresponding Applicant - CPRD
Achim Wolf - Collaborator - CPRD
Daniel Modin - Collaborator - University of Copenhagen
Deborah Rudin - Collaborator - Sanofi Pasteur SA (France) - office closed
Eleanor Yelland - Collaborator - CPRD
Helen Booth - Collaborator - CPRD
Helene Bricout - Collaborator - Sanofi Pasteur MSD ( closed )
Hilary Shepherd - Collaborator - CPRD
Joshua Nealon - Collaborator - Sanofi Pasteur SA (France) - office closed
Rachael Williams - Collaborator - CPRD
Sandra Chaves - Collaborator - Sanofi Pasteur SA (France) - office closed
Tor Biering-Sorensen - Collaborator - University of Copenhagen
HES Admitted Patient Care;ONS Death Registration Data