The utility of faces pain scale in a chronic musculoskeletal pain model.

Objectives: The main aim of this study was to investigate the clinical utility and sensitivity to change of faces pain scale (FPS) in patients with shoulder pain, chosen as a chronic pain model. The secondary aim was to determine the association of FPS with psychologic status and quality of life of these patients.

Methods: Thirty Turkish patients with chronic shoulder pain were included in the study. Pain intensity was evaluated by visual analog scale (VAS), which is a commonly used pain scale besides FPS. Depression and quality of life were screened by Beck Depression Inventory (BDI) and Short Form-36 (SF-36). All assessments were done before and after the physical therapy.

Results: There was a statistically significant decrease in pain severity after the treatment as indicated by FPS and VAS (P=0.000). The standardized response mean (SRM) value of FPS of 2.35 was accepted as a good responsiveness. The FPS showed a strong correlation with VAS (r=0.62 and 0.73) both before and after the treatment. Also, moderate to strong correlations were detected between the FPS and physical functioning (PF), physical role (PR), bodily pain (BP), emotional role (ER), general health (GH), mental health (MH) subscales of SF-36 (r=-0.58-0.80), and BDI scores (r=0.39) before the treatment. However, there were moderate and weak correlations with FPS and PR and social functioning (SF) subscales of SF-36 only after the treatment (r=-0.52 and r=-0.39).

Conclusions: FPS is a satisfactory tool to assess pain in patients with chronic pain conditions and demonstrates sensitivity to detect changes after the treatment.