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. 2021 Mar 31;23(3):e24602. doi: 10.2196/24602

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©Xiaoyue Song, Cynthia Hallensleben, Weihong Zhang, Zongliang Jiang, Hongxia Shen, Robbert J J Gobbens, Rianne M J J Van Der Kleij, Niels H Chavannes, Anke Versluis. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 31.03.2021.

This is an open-access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work, first published in the Journal of Medical Internet Research, is properly cited. The complete bibliographic information, a link to the original publication on http://www.jmir.org/, as well as this copyright and license information must be included.

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PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) flowchart of the systematic review and meta-analysis. COPD: chronic obstructive pulmonary disease; RCT: randomized controlled trial.