Page 58 - THE PERCEPT STUDY Illness Perceptions in Physiotherapy Edwin de Raaij

Chapter 3
was consistent across 8 different conditions (Appendix A). The strongest associations were found for the illness perception dimensions of Consequences and Identity. For instance, the study by Gillanders et al 14 reported a positive association of illness perception (Consequences) with increased pain (r = 0.47) in 150 patients with chronic pain, meaning a high score on the dimension of Consequences is associated with increased pain intensity.
Physical Function The authors found moderate evidence in 10 cross-sectional studies for a positive association (ie, dysfunctional illness perceptions are associated with limitations in physical function), based on univariate regression, of all illness perception dimensions with physical function (Table 5). The positive direction of the relationship of all illness perception domains with physical function was consistent across 8 different conditions. The strongest associations were found for the dimensions of Consequences and Identity (Appendix B). For instance, the study by Sluiter and Frings-Dresen54 reported a positive association between illness perception (Consequences domain) and increased limitation in physical function (r= 0.49) in 1122 patients with chronic repetitive strain injury, meaning that a high score on the illness perception dimension of Consequences was associated with in- creased limitations in physical function.
Prognostic value of illness perceptions for pain intensity or physical function
Pain intensity Two longitudinal studies16,27 with a time interval of less than 6 months found moderate evidence of illness perceptions being prognostic for greater pain intensity on the dimension of Consequences, and limited evidence for dysfunctional illness perceptions being prognostic for greater pain intensity on the dimensions of Personal and Treatment Control, Coherence, and Emotional Response (Appendix C).Three longitudinal studies16,18,51 with time intervals of 6 to 12 months found limited evidence for illness perceptions being prognostic for more pain intensity on the illness perception dimensions of Consequences, Timeline-chronic, and Identity (Appendix C).None of the studies reported evidence for pain at the time interval of greater than 12 months.
Physical function Nine longitudinal studies7-9,12,13,16-18,42 with a time interval of less than 6 months found moderate evidence for illness perceptions being prognostic for more limitations in physical function on the illness perception dimensions of Consequences, Timeline (chronic/ cyclical), Personal Control, Identity, and Emotional Response, and limited evidence for illness perceptions being prognostic for more limitations in physical function on the dimensions of Concern and Coherence (Appendix D). The positive direction of the relationship of these illness perceptions with physical function is consistent across 8 different conditions.
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