Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.

Direct and Indirect Costs of Spondlyoarthritis Patients Pre- and Post-Diagnosis.

Kirson2,  Noam, Birnbaum2,  Howard, Rao1,  Sumati, Swallow2,  Elyse, Waldman2,  Tracy, Dayoub2,  Elias, Cifaldi1,  Mary

Abbott Laboratories, Abbott Park, IL
Analysis Group, Inc., Boston, MA


Spondyloarthritis (SpA) includes 5 related clinical conditions: ankylosing spondylitis (AS), psoriatic arthritis (PsA), undifferentiated SpA (uSpA), reactive arthritis (ReA), and enteropathic arthritis (EA). Prior research reports significant economic burden associated with subtypes of SpA, but little is known about the profile of direct (medical and prescription drug) and indirect (work loss) costs over time. This study examines direct and indirect costs of SpA patients in the US during a 3-year period starting 2 years before SpA diagnosis.


Patients aged 18–64 years with >=2 diagnoses for a subtype of SpA (ICD-9-CM: 720.0, AS; 696.0, PsA; 720.9, uSpA; 099.3 or 711.1x, ReA; or 713.1, EA) were identified in a private insurance claims database (covering 40 employers; ~9,000,000 lives) in the US (1999–2007). Patients had continuous enrollment 24 months before and 12 months after first (index) SpA diagnosis, and no claims for rheumatoid arthritis unless diagnosed with PsA. SpA patients were demographically matched to controls with no history of SpA. Per-patient direct costs for all SpA patients (N=2,194) and indirect costs (absenteeism and disability) for an employee subset (N=737) were compared with controls for 12 consecutive 3-month periods. Bootstrapping was used to compare excess costs (SpA vs. controls) within periods.


Mean excess direct (medical plus drug) costs for SpA patients ranged from $781 (P<0.01) to $2,565 (P<0.01). Mean excess medical costs increased during the year prior to index, peaked at $1,890 (P<0.01) in the 3 months after diagnosis, and decreased approximately 60% in months 4–12 post-index. Increased rheumatologist costs persisted in the post index period (excess $176 to $132, P<0.01), while total outpatient and inpatient costs fell approximately 40% and 70%, respectively, 3 months after diagnosis. Mean excess drug costs accelerated sharply post index, peaking at $786 (P<0.01), driven largely by an increase in TNFa inhibitor costs (excess $490, P<0.01, 9–12 months post-index). Mean excess indirect costs rose during the year prior to index, peaked in the 3 months following diagnosis ($789, P<0.01), but fell during the subsequent year to levels similar to those 6 months pre-index ($388, P<0.01). A decline in absenteeism accounts for >90% of the fall in indirect costs post index.


Despite post-index increases in costs associated with SpA-targeted treatment (e.g., TNFa inhibitors, rheumatologist visits), total direct and indirect costs decline considerably 3 months after diagnosis and return to pre-index levels. Further research is necessary to determine the causal relationship between treatment and potential direct and indirect cost savings.

To cite this abstract, please use the following information:
Kirson, Noam, Birnbaum, Howard, Rao, Sumati, Swallow, Elyse, Waldman, Tracy, Dayoub, Elias, et al; Direct and Indirect Costs of Spondlyoarthritis Patients Pre- and Post-Diagnosis. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :763
DOI: 10.1002/art.28531

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