Economic burden of fatigue or morning stiffness among patients with rheumatoid arthritis: a retrospective analysis from real-world data

Abstract

Objective: Determine healthcare resource utilization (HCRU) and costs associated with fatigue and stiffness among patients with rheumatoid arthritis (RA).

Methods: A retrospective claims analysis compared RA patients with fatigue or stiffness to matched RA control patients with neither. Claims from a large US commercial insurance database identified new cases of stiffness/fatigue among newly diagnosed patients. Study patients had ≥2 medical claims for RA ≥45 days apart, continuous insurance coverage ≥12 months before RA index (baseline period) and ≥12 months after fatigue/stiffness index (follow-up period). Controls had no diagnosis of fatigue or stiffness ≥12 months before index. Cases had ≥1 claim of fatigue/stiffness after RA index; the first such claim was the index date. Multivariate logistic regressions, adjusting for baseline demographics, comorbidities, medication use and HCRU, were used to predict the propensity of having a fatigue/stiffness diagnosis. Controls were propensity-score matched to cases. Generalized linear models estimated all-cause and RA-specific costs associated with resource use as well as prescription drugs, adjusting for any unbalanced covariates after propensity-score matching.

Results: Approximately 32% of newly diagnosed RA patients suffer from fatigue/stiffness. Matched cohorts were analyzed: fatigue vs. control; stiffness vs. control; fatigue and stiffness vs. control. After RA diagnosis, hospitalizations increased: 83% for fatigue, 117% for stiffness and 148% for both; total office visits increased 63%, 113% and 135%, respectively. Greater HCRU yielded significantly greater (all p < .001) per-patient-per-year hospitalization costs vs. matched controls: fatigue ($2554 vs. $1293); stiffness ($2792 vs. $892); fatigue and stiffness ($3322 vs. $1033). Per-patient-per-year costs of office visits increased significantly (all p < .001) vs. matched controls: fatigue ($1373 vs. $908); stiffness ($1580 vs. $761); fatigue and stiffness ($1989 vs. $921).

Conclusions: RA patients with fatigue and/or stiffness report more HCRU and incur significantly higher medical costs than RA patients without them.

Keywords:

• Rheumatoid arthritis
• health care resource utilization
• retrospective claims analysis
• health related quality of life

Transparency

Declaration of funding

This study was funded by AbbVie, North Chicago, IL. AbbVie was involved in developing the study concept and participated in the analysis and interpretation of the data; preparation, review and approval of the article; and decision to submit the article for publication.

Author contributions: Study design and concept: V.S., R.S., C.A., N.T. Statistical analysis: R.S., C.A. Interpretation of data and critical revision of the manuscript for important intellectual content: V.S., R.S., C.A., J.Z., J.C., A.G., N.T. All authors have read and approved the final draft of the manuscript submitted.

Declaration of financial/other relationships

V.S. has disclosed that she has received consulting fees from AbbVie, Amgen, AstraZeneca, BMS, Boehringer Ingelheim, Celltrion, EMD Serono, Genentech/Roche, GSK, Janssen, Lilly, Novartis, Pfizer, Regeneron, Sanofi and UCB. R.S. and C.A. have disclosed that they are employees of Pharmerit, which received research funding from AbbVie Inc. for this study. J.Z. has disclosed that he is an AbbVie Fellow and current PhD student at University of Illinois at Chicago (UIC). J.C., A.G. and N.T. have disclosed that they are employees of AbbVie Inc. and may own AbbVie stock. CMRO peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Acknowledgements

Medical writing assistance was provided by Joann Hettasch PhD, Fishawack Communications Inc., Conshohocken, PA, and funded by AbbVie Inc., North Chicago, IL.