Page 156 - THE PERCEPT STUDY Illness Perceptions in Physiotherapy Edwin de Raaij

Chapter 8
stance, one participant answered the question on the Coherence dimension (How well do you feel you understand your illness?) as:
“How well do you feel you understand your illness? Djee ... Again a question that does not make sense to me. How well do you feel you understand your illness? [ ... silence ... ] Yes, how well ... That’s a lousy question ... How well do you feel you understand your illness? Well, I understand I have knee complaints, but ... Let’s think. Understand very clearly or do not un- derstand at all. Well, I do understand it ... I get it ... They’ve looked inside, so ... They’ve told me what’s wrong with it. Well, what do I have to... Should I have understanding then? Do I understand it? It developed in the course of time, but... (Participant 4, Study 2.) “
The struggle of this participant illustrates the challenge on how to interpret the question. This may be indicative that one should be cautious on using only one single question about a cognitive/emotional to measure a patients’ IP dimension. A qualitative assessment is recom- mend by Van Wilgen 38, meaning that further exploration of patients’ IPs, i.e. after filling out the Brief IPQ-DLV, could be recommended7-9. This means for clinicians it could be meaningful to explore the IPs more extensively using interview techniques after a patient filled out the Dutch IPQ-DLV.
Methodological considerations
For the assessment of the different IP dimensions, using the sum score of the Brief IPQ is sometimes suggested. For instance, the construct validity of a sum score of the Portuguese Brief IPQ has been studied by Machado 25. In this study the sum score of the Brief IPQ showed internal consistency of the scale (α = .80). Our understanding of the CSM on which the IP dimension are based is that each question represents a unique IP dimension. To combine these different dimensions into one sum score is eating 9 types of different fruits and then be asked; “Which apple did you like best?”. Therefor we did not assess the internal consist- ency of the Brief IPQ-DLV. The emerging perceptions when facing a health threat (ie. MSP) is expressed in the different IP-dimensions stated in the general introduction. To merge these different dimensions into one construct to represent the patients’ IPs, violates the diversity of these dimensions.
Further, to address the Concerns around the content validity of the Brief IPQ-DLV, a revised version could be considered, though it is unlikely that an adapted version could resolve this issue. Besides the semantic issue of individual patients’ understanding of the content of the questions asked, there is a more fundamental matter to consider. The original English Brief IPQ reduced the number of questions from more than 75 questions in The Revised Illness Perception Questionnaire 28, to 9 questions, 1 per IP-dimension. Broadbent et al did not re-
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