Validation of the Japanese version of boredom proneness scale and derivation of its short version among older adults: a cross-sectional study

Boredom proneness is a common yet underexplored psychological trait among older adults, linked to depression, loneliness, and reduced quality of life. Despite its clinical relevance, validated instruments for assessing boredom in this population are scarce. This study aimed to validate the Japanese version of the Boredom Proneness Scale (JBPS) and to develop a short form specifically designed for older adults (s-BPSO). We conducted two cross-sectional surveys in Japan. The first, a paper-based survey (n = 5,382; mean age = 82), targeted community-dwelling older adults aged ≥ 75 years in Sukagawa City. The second, an internet-based national survey (n = 4,124; mean age = 66), recruited participants aged ≥ 50 years. Structural validity of the JBPS was assessed via exploratory and confirmatory factor analysis. Reliability was evaluated using internal consistency and test–retest analysis. The s-BPSO was derived using item response theory and validated independently using data from the second survey. Convergent validity was examined through correlations with validated measures of mental and physical health. The JBPS demonstrated good internal consistency (Cronbach’s α = 0.87) and test–retest reliability (ICC = 0.84). Exploratory factor analysis supported a three-factor structure, though model fit in confirmatory analysis was modest. The JBPS showed strong correlations with depressive symptoms, loneliness, and HRQOL measures. Existing short versions of the BPS performed poorly in this older sample. A newly developed 6-item short version (s-BPSO) based on a two-factor structure exhibited acceptable model fit (CFI = 0.987, RMSEA = 0.056), high internal consistency (α = 0.80), and strong correlation with the full JBPS (r = 0.86). Higher boredom scores were associated with older age, lower income and education, reduced IADL, and lower HRQOL. The JBPS and s-BPSO are valid and reliable instruments for assessing boredom proneness among older Japanese adults. The s-BPSO provides a concise alternative for use in epidemiological surveys and clinical practice. These tools may inform interventions aimed at promoting active and mentally healthy aging, and support future cross-cultural research on aging-related psychological traits.