Validation of the Revised Illness Perception Questionnaire (IPQ-R) in a sample of persons recovering from myocardial infarction--the Swedish version

When people's health is threatened, they generally develop illness perceptions to make sense of their illness. The Illness Perception Questionnaire (IPQ-R), developed by Moss-Morris et al (2002), has been widely used in many countries to measure such representations. However, since studies in this crucial research area are lacking in Sweden a Swedish version of IPQ-R was validated with a focus on the seven subscales: timeline acute/chronic, timeline cyclical, consequences, personal control, treatment control, illness coherence and emotional representations. Using confirmatory factor analysis, the aim of the present study was to validate the internal structure of the Swedish version in a sample of 202 persons (144 men and 58 women) who had been diagnosed with myocardial infarction four months earlier. Additionally, inter-correlations among the seven subscales and external concurrent validity were also investigated. The results of confirmatory factor analysis revealed that, in line with the English version of the IPQ-R, the specified seven-factor model had a satisfactory fit. One item was however not considered reliable and was therefore excluded from the instrument. The internal consistency (Cronbach's alpha coefficients) and the inter-factor correlations were relatively similar to those reported in the validation study of the original English IPQ-R. In tests of concurrent validity, the seven IPQ-R subscales were, as hypothesized, mainly associated with external variables. To conclude, the Swedish version of the IPQ-R's seven dimensions, with one item removed, (total 37 items) was found to be a reliable and valid measure of illness perception.