Background/Purpose: The risk of serious infections can vary across biologics. For example, in the 2-year AMPLE trial, serious infections occurred in 3.8% of SC abatacept-treated patients and 5.8% of adalimumab-treated patients. In the 1-year ATTEST trial, serious infections occurred in 1.9% of IV abatacept-treated patients and 8.5% of infliximab-treated patients. Little is known about the healthcare costs associated with serious infections. This study quantified real-world healthcare costs associated with serious infections among biologic-naïve RA patients initiating first-line biologic treatment. Results were used to estimate serious infection costs in a hypothetical cohort of RA patients treated with abatacept, adalimumab or infliximab based on data from AMPLE and ATTEST.
Methods: Retrospective, observational cohort study based on US administrative claims data. Study patients initiated first-line biologic treatment (abatacept, adalimumab, etanercept, certolizumab, golimumab, or infliximab) between January 1 2008 and September 1 2012 (initiation=index), were aged ≥18 years, had continuous insurance enrollment for 12 months before (baseline) and 12–24 months after (follow-up) the index date, had no baseline biologic treatment, and had ≥2 baseline medical claims with an International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) diagnosis code for RA (714.0x). Published algorithms and medical coders were consulted in compiling a list of ICD-9-CM diagnosis codes for serious infections. Patients were identified as having experienced a serious infection if they incurred a hospitalization with a primary diagnosis indicative of a serious infection. The cost of serious infections, measured during follow-up, included the cost of the serious infection hospitalization, follow-up outpatient medical claims with diagnoses of the same serious infection, and anti-infective medications.
Results: The samples included 19,412 patients with 1 year of follow-up and 11,699 patients with 2 years of follow-up: in both samples, mean age was 53 years and 77% were female. Over the 1-year and 2-year follow-ups, 3.4% (n=669) and 6.2% (n=720) of patients experienced a serious infection, respectively. The most common serious infection was pneumonia. The total mean (median) cost of serious infections per patient experiencing a serious infection was $19,072 ($10,439) in the 1-year and $21,021 ($11,306) in the 2-year groups. Applying the serious infection cost estimate to the 2-year AMPLE and 1-year ATTEST trial findings in a hypothetical cohort of 1000 biologic-naïve patients, the 2-year expected cost of serious infections per 1000 biologic-naïve patients would be $798,811 for SC abatacept (3.8%*$21,021*1000) and $1,219,237 for adalimumab; and the 1-year cost would be $362,371 for IV abatacept and $1,697,420 for infliximab.
Conclusion: In this pharmacoeconomic study of biologic-naïve RA patients initiating biologic treatment, serious infections were associated with substantial healthcare costs over 1- and 2-year periods. Biologic treatments that are associated with lower infection risk may confer important cost savings related to serious infections.
Disclosure:
S. Johnston,
Truven Health Analytics ,
3;
S. Kelly,
Bristol-Myers Squibb,
1,
Bristol-Myers Squibb,
3;
A. Nadkarni,
Bristol-Myers Squibb,
1,
Bristol-Myers Squibb,
3;
K. Wilson,
Truven Health Analytics,
3;
B. Limone,
None;
M. Hochberg,
Bristol-Myers Squibb, Eli Lilly, EMD Serono, Genentech/Roche, Novartis Pharma, Pfizer, UCB,
5,
NIH,
2.
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ACR Meeting Abstracts - https://acrabstracts.org/abstract/healthcare-costs-associated-with-serious-infections-among-biologic-naive-rheumatoid-arthritis-patients-initiating-first-line-biologic-treatment/