Psychometric Validation of the EQ-5D-3L in Patients with Nontuberculous Mycobacterial (NTM) Lung Disease Caused by Mycobacterium avium Complex (MAC)

Abstract

Purpose This analysis evaluated the psychometric properties of the EQ-5D-3L among patients with Mycobacterium avium complex lung disease (MAC-LD). Methods Data from the Phase III CONVERT trial were analyzed. Study measures including the EQ-5D-3L, St. George’s Respiratory Questionnaire (SGRQ), the 6-minute walk test (6MWT), and percent predicted forced expiratory volume in 1 second (ppFEV 1 ) were collected at baseline, month 3 (M3), month 4 (M4; only 6MWT), and month 6 (M6). Item characteristics and validity were evaluated at baseline. Test–retest reliability was assessed using intraclass correlation coefficients (ICC) and a weighted kappa statistic among a subgroup of stable patients. Validity was tested by evaluating correlations of the EQ-5D-3L index/visual analogue scale (VAS) scores with SGRQ and 6MWT and comparing mean index/VAS scores across known groups defined using 6MWT and ppFEV 1 . Responsiveness of the EQ-5D-3L was assessed using 6MWT, SGRQ, ppFEV 1 , and culture conversion as anchors. Results The index score was subject to ceiling effects, with 32.6% of patients reporting perfect health at baseline. ICCs for the index (0.80) and VAS (0.85) scores and weighted kappas for the domains (0.5–0.72) indicated adequate test–retest reliability. Correlations between the index/VAS scores and related domains of the SGRQ and 6MWT were as hypothesized (0.31–0.62), and the mean index/VAS scores were significantly different between the 6MWT and ppFEV 1 known groups (p<0.05), supporting the validity of the EQ-5D-3L. No evidence was found supporting the responsiveness of the EQ-5D-3L to changes in any of the anchors. Conclusion EQ-5D-3L exhibited evidence of validity and reliability but poor responsiveness to clinically meaningful changes in patients with MAC-LD.

Health-Related Quality of Life in Patients with Spinocerebellar Ataxia: a Validation Study of the EQ-5D-3L

“…Both coefficients passed the threshold for tolerable reliability (Kappa range: 0.44–0.93; ICC: > 0.8). Our results replicate international findings, including those for rare diseases [ 39 , 42 ], suggesting that the EQ-5D-3L shows acceptable reproducibility in SCA (Supplementary Table 4 ). Nevertheless, the results must be interpreted with caution and be seen more as a tendency regarding the small sample size of stable patients ( N < 30).…”

“…Several validation studies in different settings and patient populations found at least moderate associations between the EQ-5D and disease-specific instruments and clinical assessments [ 39 – 41 ]. Our study also confirmed moderate to strong correlations between EQ-5D-3L-dimensions, EQ-5D-3L index, and EQ-VAS with the disease-specific ratings of SARA, INAS, and ADL.…”

“…The EQ-5D-3L’s ability to detect changes in health varies greatly by setting and patient group. Shah et al [ 39 ] reported poor responsiveness of EQ-5D-3L in patients with rare lung diseases; whereas, Golicki et al [ 43 ] documented a moderate to good ability to detect changes in health in stroke patients. Compared to other HRQoL measures, the EQ-5D, especially the three-level version, is less responsive [ 32 ].…”