Reliability and validity of the Spanish Glasgow Benefit Inventory after cochlear implant surgery in adults

In recent years, the outcome assessment of subjects undergoing otorhinolaryngological (ORL) intervention has relied increasingly upon patient-reported questionnaires. The English Glasgow Benefit Inventory (GBI) is a reliable, sensitive and validated post-intervention questionnaire that is used to determine health-related quality-of-life (QoL) in patients following ORL intervention. The GBI has been translated into eight languages including Spanish. The present study aimed to determine the internal consistency and validity of the Spanish version of the GBI in patients with a cochlear implant (CI). 121 adult Spanish speaking patients with a CI were questioned retrospectively using the Spanish GBI. Reliability of the questionnaire was determined using Cronbach's α coefficient; factor analyses were performed using principal component extraction with orthogonal rotation; and validity was confirmed using Pearson's correlation coefficient. The mean total score (mean ± standard deviation) of the GBI was 35.1 ± 23.6, 47.6 ± 28.9 for General Health, 17.9 ± 33.2 for Social Benefit and 1.7 ± 27.9 for Physical Health. The reliability was above 0.70 in all test domains. Using factor analyses a 4-factor solution that explained 63.2% of the variance was reached. The objective measures: bisyllables tested without lip-reading and without masking were correlated with the total score and the General Health subscales. The Spanish GBI is a reliable and practicable instrument for the assessment of health-related QoL in Spanish adult CI users.