The role of systemic inflammatory diseases in long-term morbidity and mortality: a retrospective, matched-cohort study in the Clinical Practice Research Datalink

Study type
Protocol
Date of Approval
Study reference ID
15_214
Lay Summary

Inflammation is the body's protective response to injury or infection, and inflammatory diseases happen when this inflammation is mistakenly triggered or becomes uncontrolled. This can cause damage to healthy tissue, and can affect any of the body's systems such as inflammation of the skin in psoriasis or inflammation of the joints in rheumatoid arthritis. It has been suggested that in patients who suffer conditions such as these, the effect of persistent inflammation can cause more widespread harm, and has been linked to cardiovascular disease, cancer and death from a number of causes.
This study aims to investigate the associations between inflammatory conditions of different body systems and onset of, or death from serious diseases. Using the anonymised detailed medical records kept by GPs, we will compare the risks of developing or dying from serious diseases, such as heart disease or cancer, in people who have inflammatory diseases with people of the same age and gender but who don't have an inflammatory disease. This is important in order to improve the health of patients with inflammatory conditions, by identifying those most at risk, establishing how best to manage these risks, and targeting preventable outcomes.

Technical Summary

Background: Systemic inflammatory conditions such as rheumatoid arthritis (RA), inflammatory bowel disease (IBD) and psoriasis are known to be associated with increased risk of a variety of adverse health events, such as cardiovascular disease, strokes, cancer and death. Observational studies examining outcomes in patients with inflammatory conditions are limited, and comparison of the risks between diseases has not been possible.
Primary aim: To estimate the relative effect of systemic inflammatory conditions on the risk of serious adverse health outcomes such as myocardial infarction (MI), venous thromboembolism (VTE), cancer, infection or death.

Methods: A retrospective matched cohort study utilizing data from Clinical Practice Research Datalink (CPRD). Exposed individuals will be those with diagnoses of systemic inflammatory diseases (SID) from 1998-2003. Incidence rates of outcomes of interest will be calculated and compared in each disease group.

Collaborators

Lorna Clarson - Chief Investigator - Keele University
Lorna Clarson - Corresponding Applicant - Keele University
Alyshah Abdul Sultan - Collaborator - AstraZeneca Ltd - UK Headquarters
Christian Mallen - Collaborator - Keele University
John Belcher - Collaborator - Keele University
Rebecca Whittle - Collaborator - Keele University

Linkages

HES Admitted Patient Care;ONS Death Registration Data;Patient Level Index of Multiple Deprivation;Practice Level Index of Multiple Deprivation