Inflammatory arthritis includes several different conditions causing inflamed joints. The commonest types are “rheumatoid arthritis”, “psoriatic arthritis”, and “axial spondyloarthritis”. It is common, affecting 1 in 100 people.
Despite the availability of effective medicines to control inflammation, many people with inflammatory arthritis suffer daily pain, which has a major impact on their lives.
Although it is commonly believed that pain-killers reduce inflammatory arthritis pain, research has shown they don’t help everyone. Despite this, studies from other countries demonstrate that inflammatory arthritis pain is often treated with long-term pain-killers. This is a worrying problem, as pain-killers often cause side-effects, which can be severe. It is not known if this also happens in the English NHS.
Our study will investigate this, through answering the following questions:
1. How often are people with inflammatory arthritis prescribed pain-killers?
2. Are certain people with inflammatory arthritis more likely to be prescribed pain-killers, or to be prescribed them long-term?
3. Are pain-killers prescribed differently to people with inflammatory arthritis living in different parts of England?
4. Has the prescribing of pain-killers to people with inflammatory arthritis changed over time?
This project forms part of a larger programme of work, and the answers to these questions will be considered alongside the results of other studies outside of the CPRD (examining how people with inflammatory arthritis use pain-killers, the non-drug pain treatments they receive, and the risks/benefits of pain treatments) to develop recommendations about the best way to treat pain in people with inflammatory arthritis.
BACKGROUND
Inflammatory arthritis groups diseases involving immune-driven joint inflammation. Its three main forms – rheumatoid arthritis (RA), psoriatic arthritis (PsA), and axial spondyloarthritis (axial SpA) – affect 1-2% of UK adults.
Pain is a major problem for patients with inflammatory arthritis and is the symptom they most want improving. International data suggest inflammatory arthritis pain management overuses long-term analgesia, despite their relative inefficacy/risks. The extent to which this occurs in England is uncertain. Our study will address this knowledge-gap.
AIM
To describe analgesia prescribing in patients with inflammatory arthritis managed in the English NHS, and identify risk factors for receiving long-term analgesia prescriptions.
OBJECTIVES
To undertake the following in patients with inflammatory arthritis (RA, PsA, axial SpA) using CPRD Aurum:
1. Develop a method to determine patients diagnosed with inflammatory arthritis in English primary-care records.
2. Describe the annual prevalence of analgesia prescriptions amongst patients with diagnosed inflammatory arthritis, and how this differs: (a) by patient/arthritis characteristics; (b) geographically; (c) over time.
3. Define their risk factors for receiving long-term analgesia prescriptions.
METHODS
Study 1: iterative meetings will develop SNOMED/Read code lists with/without algorithms to determine patients diagnosed with inflammatory arthritis; cross-sectional analyses will establish if these determine patient groups with expected characteristics (e.g. receiving immunosuppression).
Study 2: cross-sectional analyses will describe the annual prevalence of analgesia prescriptions in patients with inflammatory arthritis from 2004-2020. This will be stratified by analgesia-type (e.g. opioid/NSAID), patient/arthritis characteristics (age, gender, ethnicity, English Index of Multiple Deprivation quintiles [where available], arthritis duration/subtypes), geographical region. Joinpoint regression will examine changes in time-trends of analgesia prescription prevalence.
Study 3: a retrospective cohort study using Cox proportional hazards models will test the association between risk factors at arthritis diagnosis (e.g. depression diagnosis) and the outcome of time to receiving a long-term opioid, oral NSAID, or gabapentinoid prescription.
STUDY 1
Methods to establish the diagnosis of RA, PsA, and axial SpA in CPRD Aurum.
STUDY 2
Analgesia prescriptions for patients with inflammatory arthritis.
STUDY 3
Time to receipt of a long-term opioid, oral NSAID, or gabapentinoid prescription following a diagnosis of inflammatory arthritis.
Ian Scott - Chief Investigator - Keele University
Ian Scott - Corresponding Applicant - Keele University
Christian Mallen - Collaborator - Keele University
Helen Twohig - Collaborator - Keele University
James Bailey - Collaborator - Keele University
Kelvin Jordan - Collaborator - Keele University
Samantha Hider - Collaborator - Keele University
Sara Muller - Collaborator - Keele University
HES Admitted Patient Care;Patient Level Index of Multiple Deprivation