Rheumatoid Arthritis (RA) is the commonest inflammatory arthritis affecting 1% of the general population. Improvement in disease modifying anti-rheumatic drug (DMARD) treatment means that pain and swelling in joints is now well-controlled for most people with this condition, but they still have an increased risk of dying prematurely. Leading causes of death are heart diseases, infection, cancer and lung scarring (fibrosis).
Hydroxychloroquine is used in RA as an anti-arthritis medicine, and there are several reasons to suggest that it could reduce the risk of premature death in patients with RA. For example, it improves longevity in lupus, and it prevents heart attacks in people with RA. Laboratory studies demonstrate that hydroxychloroquine improves the immune system’s ability of fighting infections, and that it may reduce the risk of cancer and of lung scarring.
In this study we wish to test the theory that people with RA who are prescribed hydroxycholorquine have a lower risk of dying than others. As hydroxycholorquine is a cheap and well-tolerated treatment, if confirmed, this would have far-reaching benefits for RA patients.
Objectives: To compare all-cause and cause-specific mortality between incident cases of Rheumatoid arthritis who are prescribed and who are not prescribed hydroxychloroquine.
Methods: A cohort study using a propensity score adjusted landmark analysis of patients with Rheumatoid arthritis in the Clinical Practice Research Datalink (CPRD). Baseline characteristics and data on medication exposure will be extracted from the CPRD, and data on the outcomes (death, date of death and cause of death) will be extracted from linked ONS mortality data.
Data analysis: A propensity score for the probability of each patient receiving hydroxychloroquine within 12 months after diagnosis will be calculated using logistic regression. Mortality will be compared in the hydroxychloroquine group and non-hydroxychloroquine group using Kaplan-Meier survival and cox proportional hazards analysis, adjusting for the propensity score, and for the confounding effects of statin and anti-platelet prescription. As a sensitivity analysis exposure to hydroxychloroquine will be re-defined as a time-varying covariate.
Death (age at death) Cause-specific mortality – i.e. mortality rate due to infection, cardio-vascular disease, cancer, idiopathic pulmonary fibrosis
Matthew Grainge - Chief Investigator - University of Nottingham
Fiona Pearce - Corresponding Applicant - University of Nottingham
Abhishek Abhishek - Collaborator - University of Nottingham
Hannah Fleet - Collaborator - University of Nottingham
Peter Lanyon - Collaborator - Nottingham University Hospitals
ONS Death Registration Data;Patient Level Index of Multiple Deprivation;Practice Level Index of Multiple Deprivation