Identification of Acute Giant Cell Arteritis in Real-World Data Using Administrative Claims-Based Algorithms

Measuring treatment outcomes and change in disease activity in giant cell arteritis: a systematic literature review informing the development of the EULAR-ACR response criteria on behalf of the EULAR-ACR response criteria in giant cell arteritis task force

OBJECTIVES

To identify criteria and descriptors used to measure response to treatment and change in disease activity in giant cell arteritis (GCA).

METHODS

A systematic literature review (SLR) to retrieve randomised controlled trials (RCTs) and longitudinal observational studies (LOS). Criteria and descriptors of active disease, remission, response, improvement, worsening and relapse were extracted. RCTs, LOS with >20 subjects, and qualitative research studies were included.

RESULTS

10 593 studies were retrieved, of which 116 were included (11 RCTs, 104 LOS, 1 qualitative study). No unified definition of response to therapy was found. Most RCTs used composite endpoints to assess treatment outcomes. Active disease was described in all RCTs and 19% of LOS; and was largely defined by a combination of clinical and laboratory components. Remission was reported in 73% of RCTs and 42% of LOS; It was predominantly defined as the combination of clinical and laboratory components. One LOS reported response with a definition resembling the definition of remission from other studies. Improvement was rarely used as an endpoint and it was mostly a surrogate of remission. No study specifically defined worsening. Relapse was reported in all RCTs and 86% of LOS. It was predominantly defined as the combination of clinical, laboratory and treatment components.

CONCLUSIONS

The results of this SLR demonstrate that definitions of response used in clinical studies of GCA are scant and heterogeneous. RCTs and LOS mainly used remission and relapse as treatment outcomes. The descriptors identified will inform the development of the future European Alliance of Associations for Rheumatology-American College of Rheumatology response criteria for GCA.

Is there a role for Pneumocystis jiroveci pneumonia prophylaxis in giant cell arteritis or polymyalgia rheumatica?

BACKGROUND

Pneumocystis jiroveci pneumonia (PJP) is an opportunistic fungal infection that affects immunocompromised patients. The objective of this study was to describe the incidence of PJP among patients with giant cell arteritis (GCA) or polymyalgia rheumatica (PMR).

METHODS

A retrospective cohort study of incident cases of GCA and PMR was conducted using claims data from the TriNetX database to describe the incidence of PJP during the first 6 months of therapy. Additionally, a systematic review was performed to identify other publications describing PJP among patients with GCA or PMR.

RESULTS

During 547 patient-years of follow-up time, no cases of PJP were identified among 1,168 cases of GCA (incident rate 0 per 1,000 person-years); during 7,446 patient-years of follow up time, one case of PJP was identified out of 15,575 cases of PMR (incident rate 0.07 cases per 1,000 patient-years). This patient was alive at last follow up. Our systematic review identified 1 case-control study, 4 cohort studies, and 18 case series / case reports of PJP among patients with GCA or PMR. The incident rate of PJP was reported from one additional study for GCA and was estimated at 0.08 cases per 1,000 person years; no additional cohort studies were identified for patients with PMR. Over the entirety of the published literature, the total number of cases identified among case series and case reports was 33, from which 4 total deaths were identified.

CONCLUSIONS

Patients with newly diagnosed GCA or PMR rarely develop PJP. Existing data does not support routine prescribing of PJP prophylaxis for either group of patients.

Giant cell arteritis treatment patterns and rates of serious infections

OBJECTIVES

Giant cell arteritis (GCA) afflicts older adults who may have age- and comorbidity-related risks for infection and is treated with immunosuppressants that increase risk of infection. We examined GCA treatment patterns and rates of serious infections in two real-world cohorts in the U.S.

METHODS

We identified two GCA cohorts using two U.S. health insurance databases, Medicare (public, 2007-2017) and MarketScan (commercial, 2015-2019), by applying a validated claims-based algorithm with positive predictive value 79.0% for GCA. We required age ≥50 years and assessed baseline comorbidities, dispensing of immunosuppressants and prophylactic antibiotics, and vaccine administration. We calculated incidence rates (IR) of serious infections, defined as bacterial or viral infections requiring hospitalisation based on primary inpatient diagnosis code. Multivariable Cox proportional hazards models estimated hazard ratios for risk of serious infection for prespecified covariates.

RESULTS

The Medicare cohort included 734 patients, 28% male, mean age 77.1; the MarketScan cohort included 1022 patients, 30% male, mean age 68.4. More than 85% used prednisone ≥60mg daily at index date and <10% used tocilizumab. Serious infections developed in 27.9% of Medicare and 7.2% of MarketScan patients: IR per 100 person-years = 10.7 (95% CI 9.3, 12.2) in Medicare and 6.3 (95% CI 5.0, 7.9) in MarketScan. Older age and higher frailty score were significantly associated with increased risk for serious infection.

CONCLUSIONS

In these two U.S. GCA cohorts, high-dose glucocorticoids were the most common initial treatment, and over 25% of Medicare and 7% of MarketScan patients developed serious infection during follow-up. Older age and higher frailty score were associated with higher risk of serious infections, though maximum daily prednisone dose was not. Pneumocystis jiroveci pneumonia was rare in two GCA cohorts despite infrequent use of prophylactic antibiotics.

Risk of venous and arterial thromboembolism in patients with giant cell arteritis and/or polymyalgia rheumatica: A Veterans Health Administration population-based study in the United States

BACKGROUND

Giant cell arteritis (GCA) and polymyalgia rheumatica (PMR) are systemic inflammatory diseases that primarily affect elderly women.

OBJECTIVES

To compare the risk of thromboembolic events and retinal vascular occlusions in GCA and/or PMR with that in osteoarthritis (OA), evaluating a veteran-based population.

METHODS

A total of 1535 patients with GCA, 10,265 with PMR, and 1203 with overlapping disease, as well as 39,009 age- and sex-matched patients with OA were identified in this retrospective study. The incidence rate ratios (IRRs) of pulmonary embolism (PE), deep venous thrombosis (DVT), arterial thromboembolism, central retinal artery occlusion, and central retinal vein occlusion were calculated and examined over time. The cumulative incidence was plotted and hazard ratios (HRs) of thromboembolic events were calculated, adjusting for independent risk factors of thromboembolism.

RESULTS

Patients with GCA and overlapping disease exhibited higher IRRs for all thromboembolic events compared to patients with OA. Patients with GCA had a higher risk of developing DVT and retinal vascular occlusions than those with overlapping disease (HR: 2.01, 95% confidence interval [CI]: 1.35-2.99, p < 0.001; HR: 2.37, 95% CI: 1.23-4.53, p = 0.009, respectively) or PMR alone (HR: 1.89, 95% CI: 1.50-2.41, p < 0.001; HR: 4.68, 95% CI: 3.10-7.07, p < 0.001, respectively). Patients with GCA had a higher risk of developing PE than those with PMR (HR: 1.55, 95% CI: 1.1-2.18, p = 0.01).

CONCLUSION

The risk of thromboembolic events differs between GCA, PMR, and overlapping diseases. Our findings may help predict the risk of thromboembolic events based on disease phenotype.