Changing Reimbursement Criteria on Anti-VEGF Treatment Patterns Among Wet Age-Related Macular Degeneration and Diabetic Macular Edema Patients: An Interrupted Time Series Analysis

Articles in Press

Document Type : Original Article

Authors

1 School of Pharmacy, National Taiwan University, Taipei, Taiwan

2 Graduate Institute of Clinical Pharmacy, College of Medicine, National Taiwan University, Taipei, Taiwan

3 Department of Pharmacy, National Taiwan University Hospital, Taipei, Taiwan

4 Center for Geriatrics and Gerontology, Taipei Veterans General Hospital, Taipei, Taiwan

5 Center for Healthy Longevity and Aging Sciences, National Yang Ming Chiao Tung University, Hsinchu, Taiwan

6 Taipei Municipal Gan-Dau Hospital (Managed by Taipei Veterans General Hospital), Taipei, Taiwan

Abstract

Background 
To evaluate the impact of reimbursement criteria change on the utilization pattern of anti-VEGF among patients with wet age-related macular degeneration (wAMD) and diabetic macular edema (DME) separately in Taiwan.
 
Methods 
An interrupted time series analysis (ITSA) was performed using Taiwan's National Health Insurance (NHI) database, and patients with wAMD or DME diagnosis at the first injection of anti-VEGF agents was identified from 2011 to 2019. The outcome of interest was treatment gaps between injections of anti-VEGF. This outcome was retrieved quarterly, and the study period was divided into three phases in wAMD (two criteria changed in August 2014 (intervention) and December 2016 (intervention)) and two phases in DME (three consecutive criteria changed in 2016 (intervention)). Segmented regression models adjusted for autocorrelation were used to estimate the change in level and the change in slope of the treatment gaps between each anti-VEGF injection.
 
Results 
The treatment gaps between each anti-VEGF injection decreased from 2011 to 2019. The cancellation of the annual three needles limitation was associated with significantly shortened treatment gaps between the third and fourth needles (wAMD change in level: -228 days [95%CI -282, -173], DME change in level: -110 days [95%CI -141, -79]). The treatment gap between the  fifth and sixth needles revealed a similar pattern but without significant change in DME patients. Other treatment gaps revealed considerable change in slopes in accordance with criteria changes.
 
Conclusion 
This is the first nationwide study using ITSA to demonstrate the impact of reimbursement policy on treatment gaps between each anti-VEGF injection. After canceling the annual limitation, we found that the treatment gaps significantly decreased among wAMD and DME patients. The shortened treatment gaps might further link to better visual outcomes according to previous studies. The different impacts from criteria changes can assist future policy shaping. Future studies were warranted to explore whether such changes are associated with the benefits of visual effects.

Keywords

International Journal of Health Policy and Management

Articles in Press, Accepted Manuscript
Available Online from 10 June 2024

Files

History

  • Receive Date: 25 July 2023
  • Revise Date: 17 April 2024
  • Accept Date: 08 June 2024
  • First Publish Date: 10 June 2024

Share

How to cite

Statistics