Assessing the content validity of EQ-5D-5L in out-of-hospital cardiac arrest survivors: cognitive interviewing and comparative concept mapping with HUI3 and SF-36

The HUI3, SF-36, and EQ-5D-5L are instruments recommended for assessing out-of-hospital cardiac arrest (OHCA) survivors’ health-related quality of life (HRQoL). However, EQ-5D’s content validity has not been evaluated in this population. This is the first study to evaluate EQ-5D-5L’s content validity in OHCA survivors and to compare its content coverage against HUI3 and SF-36. We conducted in-depth interviews with OHCA survivors and co-survivors (caregivers) from five public hospitals in Singapore from August 2023-October 2024. We conducted concept elicitation to identify HRQoL issues relevant to OHCA survivors and cognitive interviews to evaluate the relevance, comprehensibility, and comprehensiveness of EQ-5D-5L. We applied thematic content analysis to verbatim transcripts to derive themes/subthemes. We interviewed ten survivors aged 34–74 years and eight co-survivors aged 38–73 years. We identified 47 themes/subthemes in the physical, mental, and social health domains. SF-36 demonstrated the highest content coverage( n = 11), followed by EQ-5D( n = 9), and HUI3( n = 6). Eight of the ten most frequently reported concepts by survivors and co-survivors were mapped onto the EQ-5D-5L. All participants found EQ-5D-5L to be relevant except two co-survivors who indicated it was not relevant to survivors with poor/full recovery. Items were comprehensible except anxiety/depression( n = 2), self-care( n = 1), and pain/discomfort( n = 2). Participants suggested including cognition, social activities, frustration/anger, and vitality/fatigue to increase EQ-5D-5L’s comprehensiveness. Concept mapping of the EQ-5D-5L, SF-36, and HUI3 showed that all three instruments did not demonstrate comprehensive coverage of OHCA survivors’ HRQoL; however, EQ-5D-5L, while being the briefest, showed greater coverage than HUI3. Although there is a need to supplement the EQ-5D-5L with other instruments for a more comprehensive assessment of OHCA survivors’ HRQoL, its relevance, comprehensibility, and brevity make it a suitable instrument for this population.