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Article History

Received: 11 August 2016

Accepted: 24 January 2018

First Online: 6 February 2018

Ethics approval and consent to participate

: This study used Truven MarketScan® administrative claims data. The data were de-identified and accessed in accordance with the Health Insurance Portability and Accountability Act of 1996; Institutional Review Board approval was not required for this study.

: Not applicable.

: Qiufei Ma, Mark Shilkrut, Zhongyun Zhao, Nicolas Batty, and Beth Barber are currently employed by Amgen Inc. Minming Li is a PhD candidate at the University of Massachusetts, Amherst.

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