Comparison of the psychometric properties of the FLACC scale, the MBPS and the observer applied visual analogue scale used to assess procedural pain

Abstract

Purpose: The purpose of this study was to compare the psychometric data and feasibility and clinical utility of the Face Legs, Activity, Cry and Consolability scale (FLACC), the Modified Behavioral Pain Scale (MBPS) and the Visual Analogue Scale for observers (VASobs) used to assess procedural pain in infants and young children. Patients and Methods: Twenty-six clinicians assessed videorecorded segments of 100 infants and young children who underwent a painful and/or distressing procedure in the emergency department using the FLACC scale, the MBPS and the VASobs pain and VASobs distress. Results: VASobs pain scores were lowest across all procedures and phases of procedures (p < 0.001). Inter-rater reliability was lowest for VASobs pain scores (ICC 0.55). Sensitivity and specificity were highest for FLACC scores (94.9% and 72.5%, respectively) at the lowest cut-off score (pain score two). Observers changed their MBPS scores more often than they changed FLACC or VASobs scores, but FLACC scores were more often incomplete. Reviewers did not consider any scale of use for procedural pain measurement. Conclusion: The reliability and sensitivity of the FLACC and MBPS were supported by study data but concerns about the capacity of these scales to distinguish between pain- and non-pain-related distress were raised. The VASobs cannot be recommended. Despite its limitations, the FLACC scale may be better suited than other scales for procedural pain measurement.