Health related quality of life in adults with asthma: a systematic review to identify the values of EQ-5D-5L instrument.

Introduction: The EQ-5D is the most popular generic preference-based instrument used for asthma patients. This study aims to explore the psychometric properties of the EQ-5D-5L instrument in patients with asthma and identify the EQ-5D-5L scores in these patients.

Method: PubMed, Scopus, Web of Science, Google Scholar and CEA Registry were searched with English language from 2009 until April 2020. Retrieved studies were checked against the inclusion criteria. Reference lists of the included articles were also reviewed. The quality of included articles was evaluated using Mitton checklist and the data were extracted by a reviewer and were checked by a second reviewer. Meta-analysis was done to calculate the overall scores based on type of asthma control.

Results: A total of 17 articles were included. The EQ-5D-5L scores ranged from 0.45 to 0.93 and the VAS scores ranged from 35.67 to 83.80. The EQ-5D-5L is higher in well-controlled (0.88, 95% CI: 0.81-0.96,  = 0.0001) than partly controlled (0.80, 95% CI: 0.74-0.85,  = 0.001) and poorly controlled asthma (0.72, 95% CI: 0.67-0.77,  = 0.01). Validity in two studies was weak and, in other studies, it was moderate to strong. Responsiveness of the EQ-5D-5L, that was shown in a study, was less than other generic instruments, and reliability was adequate in only study that had been reported. Ceiling effects were between 8.30% to 35%.

Conclusion: Higher score of the EQ-5D-5L was consistent with well-controlled asthma patients and those with lower severity of asthma. The assessment of psychometric properties of the EQ-5D-5L needs further observations.