Healthcare Costs of Potential Glucocorticoid-Associated Adverse Events in Patients with Giant Cell Arteritis

Figures & data

Figure 1 Study design.

Note: ^aFor conditions existing prior to GCA diagnosis.
Abbreviations: AE, adverse event; GCA, giant cell arteritis; OGC, oral glucocorticoid.

Figure 2 Sample attrition.

Notes: ^aGCA diagnosis date was defined as the first date of a GCA diagnosis during the index period. ^bThe index date was defined as the first date of OGC prescription after GCA diagnosis during the index period. ^cAnkylosing spondylitis, Crohn disease, juvenile idiopathic arthritis, polyarteritis nodosa, psoriatic arthritis, ulcerative colitis, granulomatosis with polyangiitis, systemic lupus erythematosus, and rheumatoid arthritis.
Abbreviations: aTNF, anti-tumor necrosis factor inhibitor; CTA, computed tomography angiography; GCA, giant cell arteritis; MRA, magnetic resonance angiography; OGC, oral glucocorticoid; PET-CT, positron emission topography-computed tomography; TAB, temporal artery biopsy; TCZ, tocilizumab.

Table 1 Preindex Demographics and Clinical Characteristics

	All Patients (N = 1,602)	Cumulative Dose > 0 to ≤ 2607 mg (n = 401)	Cumulative Dose > 2607 to ≤ 4800 mg (n = 404)	Cumulative Dose > 4800 to ≤ 7200 mg (n = 397)	Cumulative Dose > 7200 mg (n = 400)
Age, mean (SD), years	73.2 (10.0)	73.5 (10.7)	73.1 (9.6)	73.2 (9.8)	73.0 (9.9)
Female, %	68.9	73.3	67.3	67.3	67.5
Geographic region, %
Northeast	24.7	21.4	28.5	22.7	26.0^a
North Central	29.5	29.4	29.5	31.7	27.3
South	30.3	34.2	29.5	30.7	26.8
West	15.2	14.2	12.1	14.6	19.8
Unknown	0.4	0.7	0.5	0.3	0.3
Payer, %
Commercial	21.8	22.9	20.3	20.2	23.8
Medicare	78.2	77.1	79.7	79.8	76.3
Any glucocorticoid-related AE preindex, %	67.2	73.8	69.1	62.7^a	63.0^a
Preindex period comorbid conditions, %
Hypothyroidism	15.0	18.5	13.1^a	12.6^a	15.8
Ischemic heart disease	22.7	29.4	23.0^a	19.9^a	18.5^a
Cancer	12.5	13.7	13.9	10.8	11.5
Asthma/COPD	16.3	18.7	14.6	16.9	15.0
Preindex period Deyo-Charlson Comorbidity Index score, mean (SD)	1.65 (1.8)	2.03 (2.03)	1.67 (1.74)^a	1.50 (1.56)^a	1.39 (1.60)^a
Preindex period GCA severity measures, %
Blindness	6.9	4.7	4.7	6.5	11.5^a
Aortic aneurysm	2.7	3.0	3.0	3.0	2.0
Preindex total healthcare costs (USD), mean (SD), $	27,097 (44,926)	28,071 (33,864)	30,839 (69,324)	23,467 (33,625)	25,942 (30,712)

Notes: ^aP < 0.05 compared with > 0 to ≤ 2,607 mg cumulative dose group. Cumulative dose of OGCs was measured in the 1-year postindex period.

Abbreviations: AE, adverse event; COPD, chronic obstructive pulmonary disease; GCA, giant cell arteritis; OGC, oral glucocorticoid.

Figure 3 Proportion of patients with AEs and mean (unadjusted) AE-related costs (USD) in the 1-year postindex period.

Notes: ^aP < 0.001 compared with > 0 to ≤ 2607 mg cumulative dose group. Cumulative dose of OGCs was measured in the 1-year postindex period.
Abbreviations: AE, adverse event; OGC, oral glucocorticoid.

Figure 4 Predicted mean and predicted median AE-related costs (USD) in the 1-year postindex period.

Notes: Cumulative dose of OGCs was measured in the 1-year postindex period. Patients with USD $0 were assigned USD $1 to be included in models. Covariates were age group, sex, region, index year, AE in the preindex period, AE-related medication in the preindex period, hypothyroidism, ischemic heart disease, cancer, asthma/COPD, Deyo-Charlson Comorbidity Index, number of unique diagnosis codes and unique National Drug Codes, log of preindex costs, preindex OGC use, and an interaction between preindex OGC use and preindex OGC dose.
Abbreviations: AE, adverse event; OGC, oral glucocorticoid.

Table 2 Model Output from Gamma Cost Models

Variable	Cost Ratio	95% CI: Lower	95% CI: Upper	P value
Log(OGC dose)	1.378	1.162	1.635	<0.001
Age group: 55–64 vs 50–54	2.247	0.979	5.158	0.056
Age group: 65–74 vs 50–54	2.265	0.996	5.151	0.051
Age group: 75+ vs 50–54	5.259	2.360	11.722	<0.001
Sex: female vs male	2.108	1.549	2.867	<0.001
Region: North Central vs South/Unknown	0.741	0.511	1.074	0.114
Region: Northeast vs South/Unknown	0.508	0.343	0.751	0.001
Region: West vs South/Unknown	0.310	0.198	0.485	<0.001
Any AE in the pre-period	1.183	0.831	1.684	0.351
Any AE-related medications in the pre-period	0.705	0.470	1.057	0.091
Hypothyroidism in the pre-period	1.497	1.003	2.234	0.049
Ischemic heart disease in the pre-period	1.243	0.818	1.888	0.308
Cancer in the pre-period	0.596	0.355	1.000	0.050
Asthma/COPD in the pre-period	0.492	0.334	0.726	<0.001
Charlson Comorbidity Index in the pre-period	1.134	1.017	1.265	0.024
Number of unique 3-digit ICD-9 DX in the pre-period	1.006	0.984	1.030	0.583
Number of unique NDC codes in the pre-period	0.995	0.989	1.002	0.151
Log(pre-period total costs)	1.476	1.220	1.786	<0.001
Use of OGC in pre-period	0.499	0.196	1.272	0.145
Interaction of use of OGC in pre-period*log(cumulative OGC dose in pre-period)	1.056	0.925	1.205	0.420
Index year: 2010 vs 2009	1.510	0.957	2.382	0.076
Index year: 2011 vs 2009	2.401	1.518	3.799	<0.001
Index year: 2012 vs 2009	1.444	0.909	2.295	0.120
Index year: 2013 vs 2009	1.389	0.828	2.331	0.214
Index year: 2014 vs 2009	2.757	1.436	5.293	0.002

Abbreviations: AE, adverse event; COPD, chronic obstructive pulmonary disease; ICD, International Classification of Diseases; DX, diagnosis; NDC, National Drug Codes; OGC, oral glucocorticoid.

Data Availability

Qualified researchers may request access to data through the clinical study data request platform, www.clinicalstudydatarequest.com. Further details on Roche’s criteria for eligible studies are available here (https://clinicalstudydatarequest.com/Study-Sponsors/Study-Sponsors-Roche.aspx). For further details on Roche’s Global Policy on the Sharing of Clinical Information and how to request access to related clinical study documents, see here (https://www.roche.com/research_and_development/who_we_are_how_we_work/clinical_trials/our_commitment_to_data_sharing.htm).