Establishing intra- and inter-rater agreement of the Face, Legs, Activity, Cry, Consolability scale for evaluating pain in toddlers during immunization

BACKGROUND: The Face, Legs, Activity, Cry, Consolability (FLACC) scale is a five-item tool that was developed to assess postoperative pain in young children. The tool is frequently used as an outcome measure in studies investigating acute procedural pain in young children; however, there are limited published psychometric data in this context. OBJECTIVE: To establish inter-rater and intrarater agreement of the FLACC scale in toddlers during immunization. METHODS: Participants comprised a convenience sample of toddlers recruited from an immunization drop-in service, who were part of a larger pilot randomized controlled trial. Toddlers were video- and audiotaped during immunization procedures. The first rater scored each video twice in random order over a period of three weeks (intrarater agreement), while the second rater scored each video once and was blinded to the first rater's scores (inter-rater agreement). The FLACC scale was scored at four timepoints throughout the procedure. Intraclass correlation coefficients were used to assess agreement of the FLACC scale. RESULTS: Thirty toddlers between 12 and 18 months of age were recruited, and video data were available for 29. Intrarater agreement coefficients were 0.88 at baseline, 0.97 at insertion of first needle, and 0.80 and 0.81 at 15 s and 30 s following the final injection, respectively. Inter-rater coefficients were 0.40 at baseline, 0.95 at insertion of first needle, and 0.81 and 0.78 at 15 s and 30 s following the final injection, respectively. CONCLUSIONS: The FLACC scale has sufficient agreement in assessing pain in toddlers during immunizations, especially during the most painful periods of the procedure.