Pain Catastrophization and Fear of Movement Are Potential Moderators for Response to Treatment in Women With Fibromyalgia: Secondary Analyses of Randomized Controlled Trial.

Objective: To examine whether psychological and behavioral factors-specifically pain intensity, pain catastrophizing, fear of movement, and sleep quality at the end of the intervention-as well as baseline characteristics including physical activity levels, age, and nutritional status, moderate the effects of a multicomponent treatment on health-related quality of life and functional status in individuals with fibromyalgia (FM).

Design: Secondary analysis of randomized clinical trial.

Setting: The study was conducted in RehabilitarCenter.

Participants: Women (N=65) with a clinical diagnosis of FM were randomly allocated (1:1) into 2 groups.

Interventions: The experimental group (n=33) received a novel multicomponent treatment combining graded motor imagery and therapeutic neuroscience education, whereas the control group (n=32) received standard treatment, including pharmacotherapy and standard physician education.

Main outcome measures: The primary outcome was health-related quality of life and functional status, assessed using the Fibromyalgia Impact Questionnaire (FIQ). Potential moderators included pain catastrophizing, assessed with the Pain Catastrophizing Scale (PCS); kinesiophobia, assessed with the 17-item Tampa Scale of Kinesiophobia (TSK-17); sleep quality, assessed with the Pittsburgh sleep quality index; pain intensity, assessed with a visual analog scale; and physical activity levels, assessed with the global physical activity.

Results: The analysis revealed a significant relationship between the intervention effect and FIQ change when the PCS and TSK-17 scores decreased by more than -14.0 points and -11.4 points. Therefore, when the PCS and TSK-17 score changes exceeded -14.0 and -11.4 points, the effect of the intervention on FIQ was statistically significant. By contrast, baseline measurements did not moderate the intervention effects.

Conclusions: Pain catastrophizing and kinesiophobia are moderators of health-related quality of life and functional status in women with FM, whereas pain intensity and sleep quality do not show statistically significant interactions. Additionally, baseline measurements are not significant moderators. Further long-term studies are needed to confirm these findings.