How (Not) to Measure Loneliness: A Review of the Eight Most Commonly Used Scales.

Loneliness affects well-being and has long-term negative impacts on physical and mental health, educational outcomes, and employability. Because of those current and long-term impacts, loneliness is a significant issue for which we need reliable and appropriate measurement scales. In the current paper, psychometric properties of the eight most commonly used loneliness scales are reviewed both descriptively and meta-analytically. Results suggest that for many of the scales, the psychometric properties are promising. However, for some psychometric features, especially test-retest reliability and measurement invariance, evidence is rather scarce. Most striking, however, is the fact that all of the scales included items that do not measure loneliness. Surprisingly, for many (sub)scales, this was even the case for about half of the items. Because our measures are the foundation of our research work, it is crucial to improve the way loneliness is being measured.