The revised FLACC score: Reliability and validation for pain assessment in children with cerebral palsy

Abstract

Background and aimsPain in children with cerebral palsy (CP) is difficult to assess and is therefore not sufficiently recognized and treated. Children with severe cognitive impairments have an increased risk of neglected postoperative, procedural and chronic pain resulting in decreased quality of life. The r-FLACC (revised Face, Legs, Activity, Cry and Consolability) pain score is an internationally acclaimed tool for assessing pain in children with CP because of its ease to use and its use of core pain behaviours. In addition the r-FLACC pain score may be superior to other pain assessment tools since it includes an open-ended descriptor for incorporation of individual pain behaviours. The COSMIN group has set up three quality domains, which describe the quality of Health-Related Patient-Reported Outcomes (HR-PROs). These are reliability (internal consistency, reliability and measurement error), validity (content validity, construct validity and criterion validity) and responsiveness. The r-FLACC score has only been assessed for reliability and validity in the original English version by the developers of the score. The aim of this study is to assess reliability and validity of the r-FLACC pain score for use in Danish children with CP. MethodsTwenty-seven children aged 3–15 years old with CP were included after orthopaedic surgery. Two methods for assessment of postoperative pain were used. Pain intensity was assessed by r-FLACC, with a 2min standardized video recording of the child, and the Observational Visual Analogue Score (VAS-OBS) assessed by the parents. The COSMIN checklist was used as a guideline in the reliability and validity testing of the r-FLACC score. ResultsReliability was supported by three measurement properties. Internal consistency was excellent with a Cronbachs alpha of 0.9023 and 0.9758 (two raters). A factor analysis of the subgroups in the r-FLACC score showed unidimensionality. A test–retest showed excellent intra-rater reliability with an intraclass correlation (ICC) of 0.97530. Inter-rater reliability was acceptable with an ICC of 0.74576. Validity was supported by three measurement properties. Content validity was tested by the originators of the r-FLACC. Construct validity was supported by a significant increase in r-FLACC scores following surgery (n=17; difference 2.23; p=0.0397). Criterion validity was acceptable with Pearson's correlation coefficients of 0.76 and 0.59 when comparing r-FLACC scores and VAS-OBS scores. Conclusion and implicationsThis study benefits from a systematical approach to the validation and reliability parameters by using the COSMIN checklist as a guideline. It is evident that the r-FLACC pain score maintains its psychometric properties after translation. In conclusion, the r-FLACC pain score is valid and reliable in assessing postoperative pain in children with CP not able to self-report pain. With the r-FLACC pain score clinicians have a valid tool for assessing postoperative pain, hence increasing the quality of pain management in children with CP. In addition the validated r-FLACC score has the potential for use in interventional research regarding pain management in this vulnerable group of patients. Future perspectives include validation of the r-FLACC score for procedural and chronic everyday pain and implementation into daily practice.