Comparison of health-related quality of life and functional recovery measurement tools in out-of-hospital cardiac arrest survivors

Introduction Although a number of validated health-related quality of life (HR-QOL) instruments exist for critical care populations, a standardised approach to assessing the HR-QOL of out-of-hospital cardiac arrest (OHCA) survivors has not been developed. We sought to compare the responses of 12-month OHCA survivors to three HR-QOL and functional recovery instruments, and assess instrument validity. Methods The Victorian Ambulance Cardiac Arrest Registry invited 12-month OHCA survivors to participate in telephone follow-up between January 2011 and December 2015. Responders provided answers to the 12 Item Short Form Health Survey (SF-12), Three-Level EuroQol-5D (EQ-5D-3L) and the Glasgow Outcome Scale-Extended (GOSE). The SF-12 was also used to derive the SF-6D. Responses were used to assess the interpretability and construct validity of the instruments. Results A total of 1188 patients and proxies responded. Large ceiling effects were observed for the EQ-5D-3L (patients = 46%, proxies = 23%). Substantial variability was also observed in SF-6D responses for patients who reported full health according to the EQ-5D-3L. For patient responders, the strongest correlations were observed between the EQ-5D-3L index score and SF-6D (ρ = 0.65, p < 0.001), and between the SF-6D and SF-12 physical component (ρ = 0.69, p < 0.001). The distribution of the SF-6D and EQ-5D-3L differed significantly for patients reporting a lower or upper moderate GOSE outcome and lower or upper good recovery (p < 0.001 for all comparisons). Conclusions The EQ-5D-3L demonstrated limited interpretability due to the presence of ceiling effects. However, the measurement properties of the SF-12, SF-6D and GOSE suggest that these may be useful measures of HR-QOL and functional recovery in OHCA survivors.