Page 31 - THE PERCEPT STUDY Illness Perceptions in Physiotherapy Edwin de Raaij

Cross-cultural adaptation and measurment properties
Inventory27 was used. The ‘state anxiety’ scale was hypothesized to be significantly associated with both the Concern and the Emotional Response dimensions.
For the dimension Emotional Response of the IPQ-B dimension the Rand-3628 was used. The subscale Mental Health was hypothesized to be significantly associated with the Emotional Response dimension.
Statistical analysis
1. For cross-cultural adaptation of the IPQ-B into the Brief IPQDLV, the percentage of agreement on semantic equivalence in first-grade students, patients and physiotherapists for face and content validity was calculated.
2. For evaluation of the measurement properties of the Brief IPQDLV, reliability and agreement statistics as entity of reproducibility were calculated. For reliability the Kappa statistics (weighted) or percentage agreement and for agreement the smallest detectable change (SDC) was used. We consider Kw 0.70 as minimum standard26.
Descriptive statistics of the sample used in concurrent validity research were calculated. To assess the concurrent validity, Spearman’s Rho correlation coefficient was used. Statistical analyses were performed with SPSS 11 and MedCalc” version 8.0.2.0.
Results
Translation, face and content validity
Testing of the pre-final version Brief IPQ-DLV was performed among first-grade students, patients, and physiotherapists. There was a 75% semantic equivalence between the Brief IPQ-DLV question and the 24 students’ description. Seventeen percent stated that they understood the question, but did not give a semantically equivalence. The other eight percent did not assess the questions.
Twenty-five patients (mean age 48.2 years, SD 14.1, range 18-71) from private physiotherapy practices completed the Brief IPQ-DLV in a mean of 4.4 min (SD 2.1, range 2-10). There was a 65% semantic equivalence between the Brief IPQ-DLV question and the patient’s description of that question. The other 35% were descriptions that reflected the status of the individual’s health problem. Ninety-three percent of patients stated the questionnaire was understand- able.
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