Page 29 - THE PERCEPT STUDY Illness Perceptions in Physiotherapy Edwin de Raaij

Cross-cultural adaptation and measurment properties
Stage IV: expert committee
This committee existed of experts in the field of CSM (Kaptein and Broadbent), a Dutch language linguist and all translators. The goal was consensus among these members on semantic equivalence between the IPQ-B and Brief IPQ-DLV.
Stage V: field-testing pre-final version
Completing the questionnaire should not require reading skills beyond that of 12-year-old. This was tested among 24 first-grade students (11e13 years) of a secondary school in the Netherlands. After they read the Brief IPQ-DLV they were asked what they thought was meant by each question.
Twenty-five patients and 15 Dutch physiotherapists tested the pre-final version of the Brief IPQ-DLV for face and content validity. After completing the Brief IPQ-DLV, the patients were asked about what they thought was meant by each question.
The physiotherapists completed two questions;
1. How relevant is this Brief IPQDLV questionnaire for your daily practice?
2. Do you find the questionnaire appropriate for your patient? The psychometric properties face validity, content validity, reproducibility, and concurrent validity of the cross-culturally adapted Brief IPQ (IPQ-DLV) were evaluated.
Reproducibility
Was assessed in a convenience sample of patients, diagnosed with Chronic Obstructive Pulmonary Disease (COPD) for at least six months and who were already attending an ongoing training programme took part in our study. Reproducibility is defined as the degree in which repeated measurements in stable study persons provide similar results6. In reproducibility a distinction can be made between reliability and agreement6,26. Reliability concerns the degree to which patients can be distinguished from each other, despite measurement errors. Agreement concerns measurement error of the instrument (standard error of measurement SEM), and can therefore best be established in individuals with stability of the Response variable 23,26. The illness perceptions are the Response variables in this study and are known to be unstable over time. We, consequently, measured reproducibility in a population of individuals with a chance of stable condition, namely COPD undergoing a long-term training programme to maintain their level of physical functioning. Such a pulmonary rehabilitation programme may contribute to a stable level of an individual’s physical functioning32, thereby reducing the risk of unstable illness perceptions due to change in level of physical functioning. The change in health condition was assessed by one dichotomous item (yes/no) asking about
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