High Impact Chronic Pain and UK Biobank: presentation, transitions and targets for intervention

BACKGROUND
Nearly half of UK adults have pain in their muscles or joints lasting longer than three months (chronic pain). While most people manage well, about 25% of people have pain that has far-reaching, negative impacts on their lives, leading to disability, distress, social isolation, and high healthcare needs. Chronic pain presents in many different ways, and it is not clear why some people experience such 'high impact chronic pain' whereas others don't. We also don't know yet why some people improve, whereas others experience ongoing or even increasing impact from their pain.

AIMS OF THE RESEARCH
We aim to find out the possible causes (or 'risk factors') of high impact chronic pain. This will inform the design or choice between selfcare or treatment options that may more effectively address people's individual needs. Early care or support that target specific risk factors may also help prevent the onset of high impact chronic pain.

Specifically, we plan to use existing data from a large, national study of older adults (UK Biobank) to
1. Identify groups of people with distinct patterns of high impact chronic pain who may have different outcomes and different care needs
2. Understand the reasons why high impact chronic pain affects some more than others, and why this can change over time, focusing on the influence of:
a. psychological factors, including mood, attention, memory, ability to problem-solve
b. trauma or traumatic events that may occur at different times in people's lives (e.g., fracture, bereavement, sudden illness)
3. Identify selfcare or treatment options that can reduce the influence of these risk factors for people with chronic pain.

DESIGN AND METHODS
We will use data from UK Biobank, which includes health information from 500,000 people in the UK, who were aged 40-69 years when data collection started in 2006-2010. A questonnaire on the nature and impact of chronic pain was completed by over 173,000 participants in 2019. A second pain questionnaire will be sent to participants in 2023.

The study team will work together with patient partners on the following three workpackages:
(1) We will use state-of-the art statistical and artificial intelligence methods to identify subgroups with distinct patterns of chronic pain, and describe its impact on daily activity, mood, and healthcare use.
(2) We will use data from questionnaires and healthcare records collected over a period of more than 15 years, to investigate the role of factors that may explain changes over time in the impact of chronic pain, including (a) mood, attention, memory, problem-solving, and (b) physical or psychological trauma.
(3) Based on the results from (2) we will identify factors that can be effectively targeted by selfcare or treatment. We will then estimate how much benefit could be achieved if such interventions would successfully be offered to people with chronic pain.

PATIENT AND PUBLIC INVOLVEMENT
Research questions have been informed by patient partners, who shared their life stories, and suggested factors that may explain the development of chronic pain, and how impact can change over time. They will continue to be involved in defining and prioritising factors for analysis; reviewing interventions; interpreting results; formulating key messages and dissemination of findings.

COMMUNICATING FINDINGS
We will work together with patient partners and clinical advisors to
- Publish results in scientific journals and during (international) pain conferences
- Share our findings with other research teams and the PPIE network in APDP, and with UK Biobank
- Engage with our existing networks, including Versus Arthritis, Public Health England, NHS partners, research funders
- Design infographics, visual animations, or YouTube videos to communicate key findings in a way that is suitable for a wide audience
- Hold webinars to discuss findings and implications

BACKGROUND: Chronic pain (CP), lasting more than 3 months, represents a major global burden in terms of years lived with disability and economic impact due to healthcare use and work absenteeism. Approximately 25% of those with CP (10% of the adult UK population) experience far-reaching impact from CP, including widespread disability and distress, social exclusion, and high healthcare needs, recognised as High Impact Chronic Pain (HICP).

AIMS AND OBJECTIVES: We propose an interdisciplinary programme of research to inform prevention, selfcare and treatment options for HICP. Specific objectives are to
1. Use clustering methods to identify and describe phenotypes of HICP, and validate these in other datasets
2. Use causal inference methods to investigate the role of (a) cognitive and affective factors, and (b) trauma or traumatic events in explaining transitions of HICP
3. Identify potential targets for prevention and treatment, and estimate expected benefit from individual or population level intervention

DESIGN AND METHODS: Working with patient partners we will use data from UK Biobank to investigate changes in the impact of chronic musculoskeletal pain over time. The presence of CP was assessed in all UKB participants at inclusion in 2006-2010. A detailed CP survey was launched in 2019 (completed by >173,000 individuals) and will be repeated in 2023. Additional data on risk factors, mediating and moderating factors will be extracted from existing surveys (e.g. lifestyle, work cogntive function, mental health) and linked healthcare records (trauma, sudden illness, comorbidity). Social determinants (e.g. age, gender, ethnicity, deprivation), will be taken into account in all analyses.

DISSEMINATION: Open access publications, conference presentations, lay summaries, and infographics will be co-created with patient partners and clinical advisors, and shared within the research community, public health/clinical networks, and the wider public.