Validation of the Japanese version of boredom proneness scale and derivation of its short version among older adults: a cross-sectional study. - Takayama A; Uehara I; Yoshioka T; Takeshima T; Omae K; Shimizu S; Nakagawa H; Ozaka A; Hamaguchi S; Fukuhara S (Health and quality of life outcomes, 2026)