Igarashi, T. (五十嵐祐) (2019)
Development of the Japanese version of the three-item loneliness scale.
BMC Psychology, 7:20

Loneliness is a major risk factor for mental and physical health worldwide. The Three-Item Loneliness Scale (TIL Scale; Hughes et al., 2004) has been widely applied to measure loneliness in a simplified format, but no validated Japanese version has been developed. This study adapted the TIL Scale into Japanese and tested its reliability and validity. [Methods] The original English version of the TIL Scale was translated into Japanese, and the expressions of the Japanese version were confirmed by a back translation procedure. The translated scale was then administered to Japanese respondents recruited from an online research panel (N = 1020) and an online crowdsourcing service (N = 500). To analyze the data containing polytomous responses to the items in the scale, this study used categorical Confirmatory Factor Analysis and the Generalized Partial Credit Model based on the Item Response Theory. To evaluate the psychometric properties of the scale, this study examined factorial validity, reliability, information curves, and the associations of the scale score with demographic variables (age, gender, marital status, and living arrangements), the scores of the Revised UCLA Loneliness Scale (R-UCLA), the Big Five scale of personality traits, and the sizes of personal networks. [Results] The translated TIL Scale showed essential unidimensionality and characteristics to differentiate among respondents at different levels of loneliness. The scale score was related positively with the scores of R-UCLA and neuroticism and negatively with the scores of extraversion, conscientiousness, openness, agreeableness, and the sizes of overall and support networks. Those who were unmarried and alone recorded a higher score on the scale than those who were married and living with someone. Age showed a negative correlation with the scale score only in Sample 1, in which the equal allocation procedure was introduced for the age stratum. [Conclusions] The results indicate that the Japanese version of the TIL Scale demonstrates adequate reliability and validity for the assessment of loneliness.

本研究では、Hughes et al. (2004) の孤独感尺度短縮版(3項目)の邦訳版を作成し、オンラインのサンプルから収集したデータを用いて、項目応答理論に基づいて項目の特性を分析したのち、UCLA孤独感尺度やBig Five、個人の属性との基準関連妥当性を検討しています。従来の研究では、20項目のUCLA孤独感尺度が多く用いられてきましたが、本研究の知見は、3項目の短縮版が一定の識別力と妥当性を有することを示すものであり、さまざまな領域での応用が期待されます。