Incidence, prevalence, mortality and health-service use among people with systemic sclerosis (scleroderma) in the UK Clinical Practice Research Datalink

Study type
Protocol
Date of Approval
Study reference ID
16_190
Lay Summary

Systemic sclerosis (scleroderma) is a rare connective tissue disease, causing progressive thickening and fibrosis of the skin, internal organs and blood vessels. In some people with systemic sclerosis, organs such as the heart, lungs or kidneys are affected. This can cause a range of potentially serious problems and early death. As it is rare, there is little currently known about its occurrence, healthcare usage by people with this condition, and its outcomes. The purpose of this study is to:
i) Find out how many people are newly diagnosed with, or living with systemic sclerosis in the UK during 1995-2014.
ii) Describe the general practice and hospital appointments, and hospital admissions of people with systemic sclerosis before and after diagnosis.
iii) Find out when and why people with systemic sclerosis in the UK die and how this differs from people without systemic sclerosis.
This information will be useful for planning services for people with systemic sclerosis, to estimate the burden of systemic sclerosis disease on individuals and the NHS, and in beginning to understand what can be done to improve the very high mortality in this condition.

Technical Summary

Objectives:
i) To estimate the incidence, prevalence, mortality
ii) Describe health service usage before and after diagnosis and
iii) Describe leading causes of death in systemic sclerosis in the UK using the CPRD and linked HES and ONS mortality data.

Methods and data analysis:
i) We will identify all cases of systemic sclerosis in the CPRD 1995-2014, and estimate incidence and prevalence using the whole CPRD as the denominator population. We will investigate the effects of the a priori confounders age, sex and socio-economic status on incidence using multi-variable Poisson regression, and on prevalence using logistic regression.
ii) In the HES-linked CPRD 1997-2014 we will describe general practice, inpatient and outpatient healthcare usage before and after diagnosis for all incident cases of systemic sclerosis and matched controls.
iii) Finally, in the HES-linked CPRD 1997-2014, we will estimate overall mortality rates using Kaplan-Meier methods, and investigate the effects of age, sex, socio-economic status and year of diagnosis on mortality using multi-variable Cox regression. We will estimate cause-specific mortality rates for people with systemic sclerosis and matched controls and using the cumulative incidence function.

Health Outcomes to be Measured

Incidence Study Diagnosis with systemic sclerosis Healthcare usage Study Number of GP appointments Hospital appointments Number and length of hospital and intensive care admissions Mortality Study Date of death Causes of death

Collaborators

Matthew Grainge - Chief Investigator - University of Nottingham
Fiona Pearce - Corresponding Applicant - University of Nottingham
Abhishek Abhishek - Collaborator - University of Nottingham
Jeremy Royle - Collaborator - Nottingham University Hospitals
Peter Lanyon - Collaborator - Nottingham University Hospitals

Linkages

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