A Qualitative Investigation of Older Adults’ Conceptualization of Quality of Life and a Think-Aloud Content Validation of the EQ-5D-5L, SF-12v2, Warwick Edinburgh Mental Wellbeing Scale, and Office of National Statistics-4.

•Older adults’ conceptualization of quality of life centered on health, ability to perform usual activities, social contact, and emotional functioning.•Older adults most often questioned the relevance of negatively phrased mental items. Functioning-focused items were preferred over subjective well-being items.•Additional relevant domains for older adults are social contact, coping, security, and control.