Assessing Pain Behaviors in Healthy Subjects Using the Critical-Care Pain Observation Tool (CPOT): A Pilot Study

The Critical-Care Pain Observation Tool (CPOT) is a behavioral scale recommended by experts for pain assessment in critically ill patients unable to verbally communicate. The main goal of this study was to determine the relationship between self-reports of pain intensity and the CPOT score, and establish the sensibility and the specificity of the CPOT to different levels of pain intensity in healthy subjects. A total of 18 healthy subjects participated in the study (mean age = 37.8 years). All subjects underwent a 2 minutes noxious cold pressor test (CPT) at 7°C. Verbal pain ratings were obtained with a visual analog scale (0-100) while pain behaviors were videotaped. Afterwards, 2 independent evaluators quantified pain behaviors using the CPOT. Interrater reliability was supported with an ICC of 0.963 (95%CI [0.904-0.986]). A moderate positive correlation between the CPOT scores and self-reports of pain intensity during the CPT was found (r = 0.52, p = 0.028). Such result indicates that subjects reporting high level of pain showed a higher number or more intense pain behaviors. A cut-off score >2.5/8 on the CPOT led to a sensibility of 64% and a specificity of 86%. Results from this pilot study support that an increase of CPOT score is correlated with moderate to high levels of pain intensity and further support the clinical use of the CPOT.