Page 95 - THE PERCEPT STUDY Illness Perceptions in Physiotherapy Edwin de Raaij

All clinical procedures used in this study were carried out in accordance with relevant guidelines and regulations of the Royal Dutch Society of Physiotherapy (KNGF).
Measurements
At baseline (T0), we collected data on demographic characteristics, the independent and depended variables listed below.
Independent variables:
Pain intensity (PI)
Average pain in the last 24 hours (11-point Numeric Rating Scale (NRS): 0 = no pain; 10 = worst pain imaginable) (13).
Physical functioning (PF)
Difficulty in performing daily activities (11-point Patient-Specific Functional Scale (PSFS): 0 = no difficulty; 10 = unable to perform activity). The PSFS is reportedly feasible and reliable (34,4).
Pain duration
Patients rated how long their pain had existed prior to consultation: 1: pain < 7 weeks; 2: pain 7-13 weeks; 3: > 13 weeks.
Number of pain sites
Based on patients’ reports, the number of different pain sites were categorized as: 1: 1-2 sites; 2: > 2 sites.
Psychological measures
The Four-Dimensional Symptom Questionnaire (4DSQ) was used to assess patients’ level of risk (low, medium or high) for developing Distress (16 items), Somatization (16 items), Anxiety (12 items), and Depression (6 items). The 4DSQ is suitable for clinical applications. The items are answered on a 5-point frequency scale. To calculate sum scores, responses are coded on a 3-point scale: “no” (0 points), “sometimes” (1 point), “regularly”, “often”, and “very often or constantly” (2 points). Then, sum scores are calculated for each dimension, and cut-off points applied to categorize each patient as at low, medium or high risk 35.
Illness perceptions
The cross-cultural adapted and validated Brief Illness Perceptions Questionnaire- Dutch lan- guage Version (IPQ-DLV) was used 17,30: this consists of nine questions of which eight were scored on an 11-point scale and cover the IP dimensions of Consequences, Timeline, Personal
A multi-center longitudinal study
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