Anaemia happens when a person has a low amount of red blood cells (or low haemoglobin) in the blood. Haemoglobin carries oxygen around the body.
Patients with anaemia can feel weak or very tired, cannot concentrate or have trouble breathing. This can cause difficulties at work or school. Anaemia can make heart and kidney disease worse.
Anaemia is very common and affects all ages. Young and/or pregnant women, children and the elderly are most affected. Nearly 1 in 3 women of child-bearing age are anaemic.
The commonest cause of anaemia is low iron levels (iron deficiency). Iron is essential for making haemoglobin. Other causes include low levels of vitamin B12 or folate.
Iron deficiency anaemia is easily treated with iron tablets or through a drip. Even so, iron deficiency and anaemia are still major health problems. We don’t know why, but it could be because healthcare professionals are unsure the best way to test, treat and follow-up anaemia.
We want to find out what GPs do about testing and treating anaemia.. We will describe who has blood tests in the GP surgery and see if any other tests are done if anaemia is present. We will describe how many people have anaemia across all ages and the types of anaemia that they have. We will explore whether anaemia is leads to being in hospital or dying.
This will help to understand current testing and highlight improvements to help patients, clinicians and researchers with this common problem.
Background
Anaemia affects approximately one-third of the world’s population, of whom around 1.2 billion are iron deficient. Anaemia results in reduced work productivity, impaired neurocognitive development in children, increased maternal morbidity and mortality and poor quality of life. It is among the five leading causes of years lived with disability. The enduring burden of anaemia suggests that current treatment strategies are not likely to meet the World Health Organisation target of a 50% reduction in anaemia by 2025. This maybe due to uncertainty regarding how best to investigate and treat anaemia.
Objective and specific aims
The objective is to describe the epidemiology of anaemia and patterns of diagnostic investigations undertaken by GPs for anaemia across all ages.
Specific aims include:
• Describing the current testing patterns for anaemia through measurements of full blood counts
• Describing the epidemiology and clinical characteristics of anaemia in primary care
• Describing the accuracy of anaemia coding in primary care compared to blood results
• Exploring the relationship between anaemia and clinical outcomes (all-cause mortality and hospitalisation at 12 months, obtained from linked mortality and Hospital Episodes Statistics datasources).
Methods
We will undertake a population-based cohort study using data from all patients registered with GP practices in CPRD AURUM between 2017 and the last date of linked data. Exposures will include age, sex, ethnicity and socioeconomic status. Key outcomes include the prevalence, underlying aetiology (e.g. iron deficiency, B12/folate deficiency, unexplained), testing patterns and clinical outcomes. We will use multivariate logistic regression to investigate these associations.
Impact, dissemination and benefit to patients
We will present the results at scientific meetings and publish in leading peer-reviewed medical journals.
Anaemia is a public health issue with uncertain consequences at all ages. Results will guide optimal therapy, minimise waste, inform future guidelines and future research.
Full blood counts tests; Haemoglobin measures; Ferritin values; Transferrin saturation; Reticulocyte counts; C-reactive protein tests; Anaemia codes; B-12 testing and results; All-cause mortality; Hospitalisations
Clare Bankhead - Chief Investigator - University of Oxford
Sharon Tonner - Corresponding Applicant - University of Oxford
Akshay Shah - Collaborator - University of Oxford
Brian Nicholson - Collaborator - University of Oxford
Cynthia Wright Drakesmith - Collaborator - University of Oxford
Joseph Lee - Collaborator - University of Oxford
Margaret Smith - Collaborator - University of Oxford
Nicholas Jones - Collaborator - University of Oxford
Noemi Roy - Collaborator - Oxford University Hospitals NHS Foundation Trust
Patrick Patrick - Collaborator - University of Oxford
Rafael Perera - Collaborator - University of Oxford
Sarah Haynes - Collaborator - University of Oxford
Simon Stanworth - Collaborator - NHS Blood and Transplant
Suzanne Maynard - Collaborator - University of Oxford
Ting Cai - Collaborator - University of Oxford
Vijay Maharajan - Collaborator - University of Oxford - Department for Continuing Education
William Elson - Collaborator - University of Oxford
Sarah Haynes - Collaborator - University of Oxford
HES Admitted Patient Care;HES Outpatient;ONS Death Registration Data;Patient Level Index of Multiple Deprivation;CPRD Aurum Pregnancy Register