Title: A decision-analysis evaluation of a diagnostic assessment tool to reduce steriod side-effects in patients with suspected polymyalgia rheumatica.
Funder: Department of Health and Social Care

Abstract: Polymyalgia rheumatica (PMR) is an inflammatory musculoskeletal disease that affects the over-50s. PMR is difficult to diagnose but in the UK is usually managed within primary care. Untreated, PMR can cause profound disability. Patients typically require at least 1-2 years of oral glucocorticoid. Existing tests for PMR are non-specific, yet if all patients with suspected PMR were referred to rheumatologists, this would overwhelm the rheumatology service.Musculoskeletal ultrasound has been claimed to be useful in the diagnosis of PMR but its diagnostic accuracy still remains unclear. This makes evaluation of its clinical and cost-effectiveness very difficult. Vascular ultrasound may help identify early giant cell arteritis (GCA), which may coexist with PMR; treating GCA early with glucocorticoids is believed to prevent ischaemic complications such as irreversible blindness. I will assess the diagnostic accuracy of a combined musculoskeletal and vascular ultrasound in suspected PMR, taking rheumatologist-confirmed diagnosis after one year as the reference standard. I will also determine the prognostic value of key clinical and ultrasound features, and systematically assess patients for glucocorticoid-related adverse effects. In addition, I will conduct GP focus-group interviews to understand what properties a putative new diagnostic test would need in order to be clinically useful. Lastly, I will use an existing cohort of patients with GCA to determine whether being on glucocorticoid treatment for pre-existing PMR protects against ischaemic complications of GCA.I will use decision analysis modelling to estimate the potential health benefits and cost-effectiveness of the proposed ultrasound if it were to be implemented in primary care before considering rheumatology referral.

Lay abstract: Polymyalgia rheumatica (PMR) is an inflammatory musculoskeletal disease that affects the over-50s. PMR is difficult to diagnose but in the UK is usually managed within primary care. Untreated, PMR can cause profound disability. Patients typically require at least 1-2 years of oral glucocorticoid. Existing tests for PMR are non-specific, yet if all patients with suspected PMR were referred to rheumatologists, this would overwhelm the rheumatology service.Musculoskeletal ultrasound has been claimed to be useful in the diagnosis of PMR but its diagnostic accuracy still remains unclear. This makes evaluation of its clinical and cost-effectiveness very difficult. Vascular ultrasound may help identify early giant cell arteritis (GCA), which may coexist with PMR; treating GCA early with glucocorticoids is believed to prevent ischaemic complications such as irreversible blindness. I will assess the diagnostic accuracy of a combined musculoskeletal and vascular ultrasound in suspected PMR, taking rheumatologist-confirmed diagnosis after one year as the reference standard. I will also determine the prognostic value of key clinical and ultrasound features, and systematically assess patients for glucocorticoid-related adverse effects. In addition, I will conduct GP focus-group interviews to understand what properties a putative new diagnostic test would need in order to be clinically useful. Lastly, I will use an existing cohort of patients with GCA to determine whether being on glucocorticoid treatment for pre-existing PMR protects against ischaemic complications of GCA.I will use decision analysis modelling to estimate the potential health benefits and cost-effectiveness of the proposed ultrasound if it were to be implemented in primary care before considering rheumatology referral.

Research activity codes: 3.1 PRIMARY PREVENTION INTERVENTIONS TO MODIFY BEHAVIOURS OR PROMOTE WELL-BEING;4.2 EVALUATION OF MARKERS AND TECHNOLOGIES
Health categories: MUSCULOSKELETAL