Vascular ulcers are open breaks in the skin, often commencing after a minor injury. Most heal but some persist, particularly if other factors are involved. Vascular ulcers are common in people with vascular disease and in the elderly. Most vascular ulcers are caused by problems to do with the blood vessels which affect the flow of blood to and from the skin, which includes disorders of the deep veins, the superficial veins, the arteries, alone or in combination. Venous disease (caused by veins not working) is found in about 80% of vascular ulcers, arterial disease (caused by arteries not working) in about 15% of ulcers and other causes (including diabetes and rheumatoid arthritis as well as some rare conditions) occur in about 5% of ulcers. Problems in the blood vessels can occur on the surface of the leg, for example varicose veins which are enlarged, often lumpy and visible veins; or they occur deeper in the leg, for example due to a blood clot in a vein, or by a narrowing of the arteries in the leg. The treatment of the ulcer, the prevention of further problems, depend on its cause and factors that may delay healing like infections. With appropriate treatment, most venous leg ulcers heal within 3 to 4 months, however some persist and require more resources and cost more to treat. Therefore, recognising patients that get ulcers, the different disorders of the circulation that underlies ulcers and additional costs related with ulcers is our main task.
This analytical observational matched cohort study using CPRD Aurum data and linked HES-ONS data aims to estimate the incidence and prevalence as well as the underlying aetiology, diagnostic procedures, treatments, healthcare resource utilization (HCRU) and costs related with first time vascular ulcers.
The study population will include individuals aged 18 to <90 at risk for an incident vascular ulcer between April 2013 and the most current data available.
The study cohort will consist of patients with a first time vascular ulcer comprising venous ulcers (superficial or deep venous ulcers), arterial ulcers and mixed arterial and venous ulcers. A propensity score and calendar day matched group of patients in the study population without vascular ulcer will be identified and used as reference group for determination of incremental HCRU and costs related with a first time vascular ulcer.
Patient characteristics will be presented using number and proportions for categorical variables and mean, standard deviation for continuous variables. Crude incidence rates for vascular ulcers will be calculated from the number of patients with a first vascular ulcer divided by total sum of person time at risk in the study population. Prevalence rates of vascular ulcers will be calculated assuming exposure to a vascular ulcer from the initial ulcer diagnosis until the end of observational period. HCRU rate differences between the 2 matched patient groups will be calculated for each HCRU component and these differences will be multiplied with HCRU component-specific costs to estimate the additional costs of the vascular ulcer event. Analyses will be stratified by type of vascular ulcer, calendar year, age and gender.
The study outputs will allow clinicians and patients to have a stronger evidence base for the incidence, risk factors and types of vascular ulcers, to plan for prevention and more effective and less costly treatment.
Additional (incremental) costs related with first time vascular ulcers.
Samy Suissa - Chief Investigator - Sir Mortimer B Davis Jewish General Hospital
Samy Suissa - Corresponding Applicant - Sir Mortimer B Davis Jewish General Hospital
Alexander Cohen - Collaborator - King's College London (KCL)
Arina ten Cate-Hoek - Collaborator - Maastricht University Medical Centre
Audray St-Jean - Collaborator - Sir Mortimer B Davis Jewish General Hospital
Safa Salim - Collaborator - Imperial College London
Serena Granziera - Collaborator - San Giovanni and Paolo Hospital
Sophie Dell'Aniello - Collaborator - McGill University
Stephen Black - Collaborator - Guy's & St Thomas' NHS Foundation Trust
Carlos Martinez - Collaborator - Institute for Epidemiology, Statistics and Informatics GmbH (Pharma Epi)
Christopher Wallenhorst - Collaborator - Institute for Epidemiology, Statistics and Informatics GmbH (Pharma Epi)
Stephan Rietbrock - Collaborator - Institute for Epidemiology, Statistics and Informatics GmbH (Pharma Epi)
HES Admitted Patient Care;HES Diagnostic Imaging Dataset;HES Outpatient;ONS Death Registration Data;Patient Level Index of Multiple Deprivation