Objective: The aims of this study were to adapt the Swedish version of the International Outcome Inventory for Hearing Aids (IOI-HA) to the International Outcome Inventory for Alternative Interventions (IOI-AI) in the context of ear surgery (IOI-AIop) and to test the psychometric properties.
Design: The validated Swedish questionnaire IOI-HA was adapted to the IOI-AIop by omitting the question about hearing aid use and changing the term "hearing aid" to "surgery" in the remaining items. The validity, component structure and reliability of the IOI-AIop were assessed.
Study sample: Subjects diagnosed with otosclerosis and undergoing stapedotomy were included in the study (n = 162).
Results: High mean scores were noted for all items. Ceiling effects were noted, most pronounced for the satisfaction item. Principal component analysis (PCA) yielded a two-component structure explaining 77.5% of the variance. The test-retest reliability measured by intra class correlation coefficient was >0.9, and the internal consistency coefficient measured by Cronbach's alfa was >0.8.
Conclusion: The IOI-AIop showed good psychometric properties. However, ceiling effects were observed. The two-component solution was in line with previous factor analyses of the IOI-HA and the IOI-AI. The comprehensive IOI-AIop is recommended as a useful tool to evaluate patient perspectives after ear surgery.
Keywords: IOI-HA; hearing impairment; otosclerosis; outcome measures; psychometric properties; reliability; self-report; stapedotomy.