The effect on subjective quality of life of occupational therapy based on adjusting the challenge-skill balance: a randomized controlled trial.

"Declaration of conflicting interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article."

"Funding: The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This study was supported by the Japanese Association of Occupational Therapists (Grant Number 2017-04)."

"The protocol has been published in a peer-reviewed journal. This study commenced in October 2017, and the follow-up evaluation was completed in October 2018. The study was conducted according to the standards of Declaration of Helsinki and was approved by the Ethics Review Commit-tee of the Tokyo Metropolitan University (No. 17020) and was registered in the trial registry (UMIN000029505). All clients provided written informed consent."