OBJECTIVE: Otitis media in children may have a considerable impact on caregiver quality of life. The disease-specific Caregiver Impact Questionnaire is designed to assess caregiver quality of life in relation to child otitis media. Assessment of the psychometric properties of this instrument is limited. This study assesses the psychometric properties of this instrument including validity, reproducibility, responsiveness, and interpretability. STUDY DESIGN: Longitudinal validation study. SETTING: Secondary care units. METHODS: Analyses were based on data from 435 families. Validity was assessed using confirmatory factor analysis, internal consistency, and hypothesis testing. Test-retest reliability and measures of smallest detectable change were investigated in the assessment of reproducibility. Responsiveness was investigated by means of hypothesis testing and receiver operating characteristic analysis. An anchor-based distribution method was applied for determining minimal important change as perceived by the respondent. RESULTS: Factor analysis confirmed the hypothesized 1-factor structure with an acceptable fit. Cronbach's alpha was .90. In the analysis of construct validity, 88.9% of the hypothesized correlations were correctly predicted. Intraclass correlation coefficient was 0.87 and smallest detectable change corresponded to approximately one-fourth of the scale. Responsiveness was found to be good and a change score of 13.8 represented minimal important change. CONCLUSION: The modified Danish version of the Caregiver Impact Questionnaire is a valid and reproducible measurement tool that is also sensitive to measuring change in the current setting. A change score representing minimal important change as perceived by the respondent is proposed. Results of this study support the use of this instrument.
Otolaryngology - Head and Neck Surgery, 2014, Vol 151, Issue 1, p. 142-149