Classification of Loneliness using the T-ILS: Is it as simple as it seems?

Tine Nielsen, Ida Sophie Friderichsen, Signe Boe Rayce

Research output: Contribution to journalJournal articleResearchpeer-review


Student well-being is a growing issue in higher education, and assessment of the prevalence of conditions as loneliness is therefore important. In higher
education and population surveys the Three-Item Loneliness Scale (T-ILS) is used increasingly. The T-ILS is attractive for large multi-subject surveys, as it
consists of only three items (derived from the UCLA Loneliness Scale). Several ways of classifying persons as lonely based on T-ILS scores exist:
dichotomous and trichotomous classification schemes and use of sum scores with rising levels indicating more loneliness. The question remains whether TILS
scores are comparable across the different population groups where they are used or across groups of students in the higher education system. The aim
was to investigate whether the T-ILS suffers from differential item functioning (DIF) that might change the loneliness classification among higher
education students, using a large sample just admitted to 22 different academy profession degree programs in Denmark (N = 3,757). DIF was tested
relative to degree program, age groups and gender. The framework of graphical loglinear Rasch models was applied, as this allows for adjustment of sum
scores for uniform DIF, and thus for assessment of whether DIF might change the classification. Two items showed DIF relative to degree program and
gender, and adjusting for this DIF changed the classification for some subgroups. The consequences were negligible when using a dichotomous
classification and larger when using a trichotomous classification. Therefore, trichotomous classification should be used with caution unless suitable
adjustments for DIF are done prior to classification.
Original languageEnglish
JournalScandinavian Journal of Psychology
Issue number1
Pages (from-to)104-115
Publication statusPublished - 1 Feb 2021

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