Incremental Costs in Giant Cell Arteritis

Review of phase 2/3 trials in polymyalgia rheumatica and giant cell arteritis

INTRODUCTION

GCA (giant cell arteritis) and PMR (polymyalgia rheumatica) are two overlapping inflammatory rheumatic conditions that are seen exclusively in older adults, sharing some common features. GCA is a clinical syndrome characterized by inflammation of the medium and large arteries, with both cranial and extracranial symptoms. PMR is a clinical syndrome characterized by stiffness in the neck, shoulder, and pelvic girdle muscles. Both are associated with constitutional symptoms.

AREAS COVERED

In this review, we assess the established and upcoming treatments for GCA and PMR. We review the current treatment landscape, completed trials, and upcoming trials in these conditions, to identify new and promising therapies.

EXPERT OPINION

Early use of glucocorticoids (GC) remains integral to the immediate management of PMR and GCA but being aware of patient co-morbidities that may influence treatment toxicity is paramount. As such GC sparing agents are required in the treatment of PMR. Currently there are limited treatment options available for PMR and GCA, and significant unmet needs remain. Newer mechanisms of action, and hence therapeutic options being studied include CD4 T cell co-stimulation blockade, IL-17 inhibition, IL-12/23 inhibition, GM-CSF inhibition, IL-1β inhibition, TNF-α antagonist and Jak inhibition, among others, which will be discussed in this review.

Quality standards for the care of people with giant cell arteritis in secondary care

OBJECTIVE

GCA is the commonest primary systemic vasculitis in adults, with significant health economic costs and societal burden. There is wide variation in access to secondary care GCA services, with 34% of hospitals in England not having any formal clinical pathway. Quality standards provide levers for change to improve services.

METHODS

The multidisciplinary steering committee were asked to anonymously put forward up to five aspects of service essential for best practice. Responses were qualitatively analysed to identify common themes, subsequently condensed into domain headings, and ranked in order of importance. Quality standards and metrics for each domain were drafted, requiring a minimum 75% agreement.

RESULTS

13 themes were identified from the initial suggestions. Nine quality standards with auditable metrics were developed from the top 10 themes. Patient Access, glucocorticoid use, pathways, ultrasonography, temporal artery biopsy, PET scan access, rheumatology/ophthalmology expertise, education, multidisciplinary working have all been covered in these quality standards. Access to care is a strand that has run through each of the developed standards. An audit tool was developed as part of this exercise.

CONCLUSION

These are the first consensus auditable quality standards developed by clinicians from rheumatology and ophthalmology, nursing representatives and involvement of a patient charity. We hope that these standards will be adopted by commissioning bodies to provide levers for change from the improvement of patient care of individuals with GCA.

The Delay and Costs of Diagnosing Systemic Vasculitis in a Tertiary-Level Clinic

INTRODUCTION

The diagnosis of systemic vasculitis is a challenge because of the heterogeneity of clinical manifestations. The aim of this study is to analyze the diagnostic delay in systemic vasculitis, the total costs during the first year of care, and how the diagnostic delay affects the costs in a tertiary health care facility.

METHODS

Patients with a new diagnosis of systemic vasculitis between 2010 and 2018 were identified from hospital records. The diagnostic delay and health care costs were evaluated during the diagnostic period and within 12 months after the first contact with tertiary health care. Vasculitis-related costs were recorded as true costs charged. A total of 317 patients fulfilled the study criteria. The diagnoses were grouped into three clinically relevant groups: IgA vasculitis and other small-vessel vasculitis (n = 64), ANCA-associated vasculitis (AAV) (n = 112), and large-vessel vasculitis (LVV) (n = 141).

RESULTS

The diagnostic delay from the first referral to tertiary-level clinic was shortest in the LVV group and longest in the AAV group. Total costs during the diagnostic period were the highest in the AAV group (median = €6754 [IQR €8812]) and lowest in the LVV group (median = €3123 [IQR €4517]), p < 0.001. There was a significant positive correlation between the diagnostic delay and total costs during the diagnostic period and 12 months (rs = 0.38, p < 0.001 and rs = 0.34, p < 0.001, respectively). In a linear model, the inpatient days and the number of laboratory tests were the strongest predictors (p < 0.001) of a higher treatment cost during the diagnostic period.

CONCLUSIONS

There is a substantial diagnostic delay that correlates significantly with the costs in tertiary-level health care when diagnosing systemic vasculitis.

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

Objective

The objective of this study was to validate claims‐based algorithms for identifying acute giant cell arteritis (GCA) that will help generate real‐world evidence on comparative effectiveness research and epidemiologic studies. Among patients identified by the GCA algorithm, we further investigated whether GCA flares could be detected by using claims data.

Methods

We developed five claims‐based algorithms based on a combination of International Classification of Diseases, Ninth Revision (ICD‐9) diagnosis codes, specialist visits, and dispensed medications using Medicare Parts A, B, and D linked to electronic medical records (2006‐2014). Acute cases of GCA were determined by chart review using the treating physician’s diagnosis of GCA as the gold standard. Among the patients identified with acute GCA, we assessed if a GCA flare occurred during the year after initial diagnosis.

Results

The number of patients identified by each algorithm ranged from 220 to 896. Positive predictive values (PPVs) of the algorithms ranged from 60.7% to 84.8%. Requirement for disease‐specific workups, multiple diagnosis codes, or specialist visits improved the PPVs. The highest PPV (84.8%) was noted in an algorithm that required two or more diagnosis codes of GCA from inpatient, emergency department, or outpatient rheumatology visits plus a prednisone‐equivalent dose greater than or equal to 40 mg/day occurring 14 days before or after the second ICD‐9 diagnosis date, with the cumulative days’ supply greater than or equal to 14 days. Among patients identified as having GCA, 18.2% of patients had definite evidence of a flare and 25% had a potential flare.

Conclusion

A claims‐based algorithm requiring two or more ICD‐9 diagnosis codes from inpatient, emergency department, or outpatient rheumatology visits and high‐dose glucocorticoid dispensing can be a useful tool to identify acute GCA cases in large administrative claims databases.

The challenges of pharmacoepidemiology of orphan drugs in rare diseases

Large electronic health records database available at a national level offer great opportunity for research in rare diseases and orphan drugs. Methods and data used in pharmacoepidemiology present a great potential for epidemiology, drug utilization studies, drug safety, drug effectiveness and pharmacoeconomics. This review presents the different sources of data in Europe, with a special focus on the French situation, with the recent implementation of SNDS (système national des données de santé [French national health data wharehouse]). Some examples are given. Development of rigorous and innovative methods must be encouraged in the future.

Data linkage analysis of giant cell arteritis in Italy: Healthcare burden and cost of illness in the Italian region of Friuli Venezia Giulia (2001-2017)

Giant cell arteritis (GCA) is the most common vasculitis in adults. However, comprehensive analyses of the healthcare burden are still scarce. The aim of the study is to report the healthcare burden and cost of illness of GCA in the Friuli Venezia Giulia (FVG) region of Italy, based on a data linkage analysis. To this end, a retrospective study was conducted through the integration of many administrative health databases of the FVG region as the source of information. Cases were identified from two verified, partially overlapping sources (the rare disease registry and medical exemption database). From 2001 to 2017, 208 patients with GCA were registered. The prevalence of GCA in the population aged ⩾ 45 years as of December 31, 2017 was 27.2/100,000 inhabitants (95% CI 23.5-31.4). The mean time of observation was 4.5 ± 3.6 years. A total of 3182 visits (338 per 100 patient-years) was recorded. The most frequent specialty visits were rheumatology (n = 610, 19.2%), followed by internal medicine (n = 564, 17.7%). A total of 287 hospitalizations (30 per 100 patient-years) were reported. A total of 13,043 prescriptions (1386 per 100 patient-years) were registered. More than half of the patients were prescribed an immunosuppressive agent. The overall estimated direct healthcare cost was €2,234,070, corresponding to €2374 per patient-year. Overall, GCA is a rare disease which implies a high healthcare cost.

Characteristics and management of giant cell arteritis in France: a study based on national health insurance claims data

Objective

Few data are available on the epidemiology and management of GCA in real life. We aimed to address this situation by using health insurance claims data for France.

Methods

This retrospective study used the Echantillon Généraliste de Bénéficiaires (EGB) database, a 1% representative sample of the French national health insurance system. The EGB contains anonymous data on long-term disease status, hospitalizations and reimbursement claims for 752 717 people. Data were collected between 2007 and 2015. The index date was defined as the date of the first occurrence of a GCA code. Demographics, comorbidities, diagnostic tests and therapies were analysed. Annual incidence rates were calculated, and incident and overall GCA cases were studied.

Results

We identified 241 patients with GCA. The annual incidence was 7–10/100 000 people ⩾50 years old. Among the 117 patients with incident GCA, 74.4% were females, with mean age 77.6 years and mean follow-up 2.2 years. After the index date, 51.3% underwent temporal artery biopsy and 29.1% high-resolution Doppler ultrasonography. Among the whole cohort, 84.3% used only glucocorticoids. The most-prescribed glucocorticoid-sparing agent was methotrexate (12.0%).

Conclusion

The incidence of GCA in France is 7–10/100 000 people ⩾ 50 years old. Adjunct agents, mainly methotrexate, are given to only a few patients. The use of temporal artery biopsy in only half of the patients might reflect a shift toward the use of imaging techniques to diagnose GCA.

Additional Costs of Polymyalgia Rheumatica With Giant Cell Arteritis

OBJECTIVE

To assess and compare direct costs between patients with giant cell arteritis (GCA) that is associated or not associated with polymyalgia rheumatic (PMR), and to identify the additional cost drivers due to PMR.

METHODS

A population-based, retrospective cohort study using the French National Health Insurance System Database was conducted. Cost analysis was performed from the French health insurance perspective and direct medical and nonmedical costs were taken into account (based on 2014 costs [€]). Costs were analyzed according to different components and divided into 6-month periods to assess care consumption. Longitudinal multivariate analyses, using generalized estimating equations, were used to adjust the effect of PMR on the mean cost over time.

RESULTS

Analyses were performed on 100 incident patients with GCA, 54 of whom had PMR. The cumulative additional cost due to PMR was €8,801 for 3 years, and €10,532 for 5 years. The significant additional costs occurred especially during the second and third years of follow-up, amounting to €1,769 between 12 and 18 months (P = 0.02), €1,924 between 18 and 24 months (P = 0.17), €1,458 between 24 and 30 months (P = 0.08), and €1,307 between 30 and 36 months (P = 0.07). The most important cost drivers were inpatient stays, paramedic procedures, and medications. Multivariate analyses showed a significant effect of PMR on mean cost during the first 3 years of follow-up (relative risk 1.76 [95% confidence interval 1.03-2.99], P = 0.038).

CONCLUSION

To our knowledge, this study is the first to accurately assess the cost of PMR care in patients with GCA and to highlight that PMR is largely responsible for the high cost of GCA.