Systemic lupus erythematosus (SLE) is a rare auto-immune condition causing inflammation within the body. It can affect different organs of the body including the kidneys and brain. It is a chronic condition often causing frequent episodes of inflammation. These episodes can sometimes be life threatening. They can also leave lasting damage, even when the inflammation has settled.
The SLICC/ACR damage index (SDI) is a score used to measure the amount of organ damage in patients with SLE. It encompasses many items which relate to damage in specific organs and is specifically used to study SLE. We know that it helps predict survival.
SLE is a rare condition, making it difficult to study organ damage and its relationship with symptoms and other health problems. The CPRD offers the opportunity to study large numbers of SLE patients and might help us better understand who is at most risk of damage. Knowing this may help us choose the best treatments to reduce this. However, it is not known how well the SDI will work within the CPRD, as the data is different to traditional research studies from where the SDI was derived.
We plan to evaluate how organ damage is recorded in SLE patients within the CPRD. We plan to adapt the existing SDI so it can be used to investigate organ damage within the CPRD and other electronic health records. We will then investigate rates of organ damage and the factors that predict who is most at risk of organ damage.
Systemic lupus erythematosus (SLE) is a rare disease: exploration of organ damage and disease trajectories following diagnosis has been limited. Electronic healthcare records (EHRs) offer the opportunity to study large cohorts of SLE patients over a prolonged period. This study aims to develop, an instrument (eSDI), for damage estimation, usable within EHR datasets. With better understanding of disease trajectories, patients will benefit through enhanced surveillance, screening and instigation of preventative measures for high-risk individuals.
Initially the study will evaluate the function of an established SLE damage index (SDI) within EHRs: we will describe the recording of SDI items in SLE patients, by reporting item prevalence. We will explore additional clinical events representing damage not currently recorded in the SDI but associated with an increased risk of mortality. Through an expert consensus review we will determine which SDI items should be included within the “eSDI”. Using an SLE and matched non-SLE group (6:1 matching) we will test the ability of the eSDI to predict overall mortality using logistic regression; survival analysis will be used to compare differences in mortality from index date. This will be developed using CPRD GOLD, then tested in Aurum.
We will then use the eSDI to describe patterns of damage accrual within an incident SLE, and matched non-SLE, population over time. We will report mean and median for total damage score by time interval and we will use Kaplan-Meier plots to identify differences in development of damage over time, stratifying by levels of damage. Accrual of items in the eSDI will be identified and evaluated using a multistate model where each increase in eSDI will be defined as a transition and modelling will be according to transition rate; time from index date and time from last transition will also be evaluated.
All-cause mortality; Clinical events representing organ damage related to SLE as defined by the SDI; Clinical events representing organ damage not defined within the SDI.
Sarah Skeoch - Chief Investigator - University of Bath
Jessica Ellis - Corresponding Applicant - University of Bath
Anita McGrogan - Collaborator - University of Bath
John Pauling - Collaborator - University of Bath
Julia Snowball - Collaborator - University of Bath
Neil McHugh - Collaborator - University of Bath
Rachel Charlton - Collaborator - University of Bath