Increased Frequency and Costs of Ambulatory Medical Care Utilization Prior to the Diagnosis of Rheumatoid Arthritis: A National Population-Based Study

Authors

  • Ning-Sheng Lai,

    1. Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Chiayi, and School of Medicine, Tzu Chi University, Hualien, Taiwan
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    • Drs. Lai and Tsai contributed equally to this work.

  • Tzung-Yi Tsai,

    1. Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Chiayi, Tzu Chi College of Technology, Hualien, and College of Medicine, National Cheng Kung University, Tainan, Taiwan
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    • Drs. Lai and Tsai contributed equally to this work.

  • Chung-Yi Li,

    1. College of Medicine, National Cheng Kung University, Tainan, and College of Public Health China Medical University, Taichung, Taiwan
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  • Malcolm Koo,

    1. Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Chiayi, Taiwan
    2. Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
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  • Chia-Li Yu,

    1. National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
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  • Ming-Chi Lu

    Corresponding author
    1. Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Chiayi, and School of Medicine, Tzu Chi University, Hualien, Taiwan
    • Division of Allergy, Immunology, and Rheumatology, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, No. 2, Minsheng Road, Dalin, Chiayi, Taiwan 62247. E-mail: e360187@yahoo.com.tw

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  • The interpretation and conclusion contained herein do not necessarily represent the positions of the Bureau of National Health Insurance, the Department of Health, or the National Health Research Institutes.

Abstract

Objective

To investigate the frequency and costs associated with ambulatory medical care utilization over an 8-year period in patients prior to the diagnosis of rheumatoid arthritis (RA).

Methods

We used Taiwan's National Health Insurance Research Database to identify 691 newly diagnosed RA cases between 2005 and 2010. We selected 1,382 controls without RA, frequency matched by sex, age, and the catastrophic illness certificate application year of the cases. The frequency and costs of ambulatory medical care utilization between the RA patients and controls were compared using the 2-sample Kolmogorov-Smirnov test.

Results

The median frequency of ambulatory medical care utilization was significantly higher in RA patients compared with controls (29 versus 13; P < 0.001) in the year before diagnosis. The differences remained significant throughout all 8 annual periods before diagnosis. Similarly, the inflation-adjusted costs of ambulatory medical care utilization in RA patients increased annually over the study period, from a median of $212 eight years preceding diagnosis to $798 one year preceding diagnosis. Frequency of ambulatory medical care utilization due to diseases of the musculoskeletal system and connective tissue (P < 0.001), acute respiratory infections (P < 0.001), diseases of the upper respiratory tract (P = 0.01), and diseases of the upper gastrointestinal tract (P = 0.04) were higher among RA patients in the 2-year period preceding diagnosis.

Conclusion

We found increased frequency and costs of ambulatory care utilization among RA patients in Taiwan preceding diagnosis of RA.

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