Psychometric evaluation of the Dutch version of the Mood, Interest and Pleasure Questionnaire (MIPQ).

Recently, several instruments have been developed to measure the subjective component of the quality of life (QOL) of people with profound intellectual and multiple disabilities (PIMD). A next step, however, must be the further validation of these instruments. The present study aimed at evaluating the psychometric properties of one of these instruments, the Dutch version of the Mood, Interest and Pleasure Questionnaire (MIPQ). The MIPQ is a 25-item Likert scale questionnaire with two subscales (Mood and Interest and Pleasure). The MIPQ and the Aberrant Behavior Checklist were completed on 360 participants with severe or profound intellectual disabilities. About 27% of these participants were included in an examination of test-retest of and the inter-rater reliability of the MIPQ. The results suggest that the proposed two-factor structure did not show an adequate fit to our data. An exploratory factor analysis revealed a three-factor structure with positive mood, negative mood and interest as three correlated but distinct subscales. These results are in concurrence with the literature on positive emotions. High internal consistency (α ≥ .80), high inter-rater (r ≥ .69) and high test-retest reliability (r ≥ .86) were found, which indicates the reliable use of the MIPQ in the population of people with PIMD. Strong negative correlations between the MIPQ total score and the Aberant Behavior Checklist's 'lethargy, social withdrawal' subscale provides some evidence of the construct validity of the MIPQ. However, further validation of the MIPQ including other measures of subjective well-being is warranted.