Osteoarthritis is very common and is the main cause of chronic joint pain and disability in older people. According to the Arthritis Research UK, three in ten people have more than one long term condition. Despite the increase in other long-term diseases such as hypertension and diabetes, there is little information available on how osteoarthritis has changed over the past 20 years in the UK. Also, there is no clear understanding of whether people with osteoarthritis are more likely to have other long-term health conditions. This research aims to answer four questions: 1) how common is osteoarthritis in the UK and what are the trends over the past twenty years; 2) are people with osteoarthritis more likely to have other long-term conditions than people without osteoarthritis; 3) which long-term conditions are more likely to co-exist with osteoarthritis and how do they progress with time; and 4) does the presence of long-term conditions in osteoarthritis add to the burden both to patients and to health services.
Osteoarthritis (OA) is a common chronic condition that has significant detrimental impact on daily activities and quality of life. There is lack of evidence on the association and/or causal relationship of OA with other chronic diseases (comorbidities) such as cardiovascular disease and diabetes. Presence of comorbidities affects management and outcome of OA in several ways. For example, some treatments (e.g. systemic analgesics) may add a further burden to the comorbidity, whereas others (e.g. exercise and weight loss) may benefit both OA and its comorbidities. This project aims to examine the trends, patterns and healthcare utilisation of OA and its comorbidities in the past 20 years in the UK using the Clinical Practice Research Data-link (CPRD). Hospital Episode Statistics (HES) will be used to determine hospitalisation. Office of National Statistics (ONS) death registration data will be used to map the death registration. Multiple deprivation index data will be used to explore the association with social factors. Trends of age-sex standardized incidence and prevalence of OA (and by body region) will be calculated for the last 20 years (1997-2017).
We will determine incident OA cases according to the first diagnosis date (index date) and match each case with a non-OA (control) by age, gender and practice on a 1:1 basis with the same index date being allocated. We will retrospectively review comorbidities diagnosed prior to the index date and follow up at-risk OA cases and matched controls for incident comorbidities after the index date. The clusters of comorbidities will be examined for differences in pattern, trajectories, health utilisation and mortality. For the retrospective study, conditional logistic regression will be used to estimate the odds ratios, and for the follow-up prospective study Cox-proportional hazard regression will be used to estimate the hazard ratios.
Primary outcome:
The primary outcome of the study will be the association between OA and a range of comorbidities. We are particularly interested in chronic widespread pain, cardio-vascular, metabolic/endocrine, respiratory, neurological, gastrointestinal, psychological, genito-urinary, neoplasm/cancer, skin and subcutaneous, behavioural and developmental problem, nutritional disorders, and sleep disorders. The full list of comorbidities is given in Appendix-3.
Secondary outcomes:
The three secondary outcomes to be studied are:
i) the trends of age-sex standardized prevalence and incidence rates of OA in the UK between 1997 to 2017;
ii) the pattern and trajectories of clustering of comorbidities in OA, their burden in terms of Disability of Adjusted Life Years (DALYs) between clusters;
iii) frequency of hospitalization, prescription and all-cause mortality across the comorbidity cluster groups
Weiya Zhang - Chief Investigator - University of Nottingham
Subhashisa Swain - Corresponding Applicant - University of Nottingham
Aliya Sarmanova - Collaborator - University of Nottingham
Carol Coupland - Collaborator - University of Nottingham
Chang-Fu Kuo - Collaborator - University of Nottingham
Christian Mallen - Collaborator - Keele University
Michael Doherty - Collaborator - University of Nottingham
HES Admitted Patient Care;ONS Death Registration Data;Patient Level Index of Multiple Deprivation;Practice Level Index of Multiple Deprivation