OBJECTIVES: Rheumatoid arthritis (RA) affects less than 1% of the US population but contributes to $22.3 billion in total annual healthcare costs.¹ Biomarker tests are used to diagnose and monitor RA. This study was conducted to determine the effects of biomarker testing on healthcare costs.

METHODS: A study was conducted using medical and pharmacy claims from 1/2019 – 7/2022. Members were split into study arms by therapy (biologic vs methotrexate (MTX) monotherapy) and line of business (Medicare or commercial). The effect of biomarker use was calculated by comparing total costs per member per month (PMPM). Biomarkers were split into three categories: diagnostic, inflammation levels, and disease monitoring. Diagnostic tests include the rheumatoid factor and cyclic citrullinated peptide antibody. Inflammatory level tests included C-reactive protein and erythrocyte sedimentation. Multi-biomarker disease activity tests were included as disease monitoring biomarkers. Statistical significance was calculated using an ordinary least squares regression; p<0.05 was deemed significant.

RESULTS: Diagnostic biomarkers saved $305.10 PMPM in the commercial MTX arm (n=7,760, p<0.01). Disease monitoring and inflammatory biomarkers showed non-significant added costs of $55.74 and $74.91 PMPM, respectively. Diagnostic biomarkers saved $875.09 PMPM, and disease monitoring biomarkers saved $242.32 PMPM in the commercial biologic arm (n=15,070, p<0.1). Inflammatory biomarkers insignificantly increased costs by $117.75 PMPM. Diagnostic biomarkers saved $134.18 PMPM in the Medicare MTX arm (n=13,964, p<0.01). Disease monitoring and inflammation biomarker tests insignificantly saved $41.61 and $122.94 PMPM, respectively. Diagnostic biomarkers saved $678.12 PMPM, and disease monitoring biomarkers saved $544.14 PMPM in the Medicare biologic arm (n=4,197, p<0.01). Inflammatory level biomarkers added an insignificant $97.45 PMPM.

CONCLUSIONS: Members with diagnostic biomarkers had significant monthly savings. As innovative biomarker tests come to market, further analysis is required to understand their therapeutic and monetary value.