THU0546 HEALTHCARE COSTS OF NOT ACHIEVING REMISSION IN PATIENTS WITH RHEUMATOID ARTHRITIS

Background: EULAR has recommended ultrasonography (US) as first imaging modality for diagnosis of Giant Cell Arteritis (GCA)1. For patients with a high pre-test probability who have a negative scan, the recommendation is to use another diagnostic modality like temporal artery biopsy (TAB) to make a diagnosis1. We know that a fast-track pathway incorporating US, results in better clinical outcomes2; but there are little data on the health-economics of this approach. Since 2017, we have used ultrasonography as the primary diagnostic modality for suspected GCA. In patients with a high pre-test probability with a negative ultrasonography, we perform a temporal artery biopsy. Objectives: To compare the cost of investigating GCA using first-line US and second-line TAB the use of TAB only. To compare the cost per definite diagnosis of GCA. Methods: Number of cases from 2007-2009 and 2017-2019 were calculated by the number of TAB performed and number of referrals to hospital GCA clinic, respectively. Costs of the procedure were calculated as per the nationally agreed tariff by the United Kingdom National Health Service. For ease of comparison, we used the 2018/19 tariff (£1284/TAB; £51 for US) Results: In 2007-2009, 162 cases were referred to clinic and had a TAB, of which 86 were positive. No cases had US. The 2018/19 corrected cost was £208008; the cost per positive diagnosis was £2418.70 (Table 1). In 2017-2019, 419 patients were referred to the GCA clinic, 416 of whom had US for diagnosis. 3 individuals had a TAB as the first diagnostic modality and 66 others were referred for a TAB because of a high pre-test probability and negative US. The 2018/19 corrected cost of this pathway was £109812 and the cost per positive diagnosis was £773.32 (Table 1). If all cases in 2017-2019 had a TAB for suspected GCA, the 2018/19 corrected cost would have been £537996. The estimated 2018/19 corrected savings in our center was £142728/year. The estimated 2018/19 corrected savings per definite diagnosis of GCA has dropped by £1645.37 (Table 1). Conclusion: The EULAR recommendation of using first-line US for diagnosis of GCA followed by a TAB in cases with uncertain diagnosis after US, is highly cost-effective in the UK, resulting in cost savings of >£140K per year. References: [1]Dejaco C, et al. Ann Rheum Dis. 2018 May;77(5):636-643. [2]Diamantopoulos AP, et al. Rheumatology (Oxford). 2016 Jan;55(1):66-70. Disclosure of Interests: None declared