J Clin Neurol.  2022 Sep;18(5):514-521. 10.3988/jcn.2022.18.5.514.

Validation of the Individualized Neuromuscular Quality of Life Questionnaire in Korean Patients With Genetic Neuromuscular Diseases

• Han HJ
• Lee SA
• Choi YC
• Rose MR
• Park HJ

• KMID: 2532695
• DOI: http://doi.org/10.3988/jcn.2022.18.5.514

Abstract

Background and Purpose
The Individualized Neuromuscular Quality of Life questionnaire (INQoL) is a widely used measure of the quality of life in patients with neuromuscular diseases. The purpose of this study was to translate and validate the Korean version of INQoL in Korean patients with neuromuscular diseases.
Methods
We translated the original INQoL version into Korean while applying appropriate language adaptations. The internal consistency, known-group validity, and test-retest reliability were also assessed. Construct validity was measured using the modified Rankin Scale (mRS) score and the manual muscle testing (MMT)-sum score based on the Medical Research Council scale, and concurrent validity was measured using the 36-item Short Form Survey (SF-36) questionnaire.
Results
This study enrolled 193 patients. The coefficients for internal consistency (Cronbach’s α=0.805 to 0.987) and test-retest reliability (Spearman’s ρ=0.453 to 0.886) were adequately high for all subscales except in the ‘treatment effects’ dimension. INQoL subscales other than those for locking, droopy eyelids, double vision, and swallowing difficulties were significantly associated with their relevant SF-36 domains (Spearman’s ρ=-0.274 to -0.833). Functional status and muscle strength were most strongly associated with independence (Spearman’s ρ=0.753 and p<0.001 for mRS score, Spearman’s ρ=-0.741 and p<0.001 for MMT-sum score).
Conclusions
The Korean INQoL is a reliable and validated measurement tool for Korean patients with neuromuscular diseases.

Keyword

neuromuscular diseases; quality of life; validation study