The Electronic Faces Thermometer Scale (eFTS)-Construct Validity for Pain Assessment in Pediatric Postoperative Care in Sweden

BACKGROUND: Pain in children is undertreated. An assessment scale co-designed with children, parents, and health care professionals could lead to more effective pain assessments and treatment strategies aimed at reducing pain and pain-related symptoms. There are analogue scales validated for self-report of pain in children, but today, children regularly use digital technology, which healthcare should align with. The newly developed electronic Faces Thermometer Scale is a digital assessment scale that needs further validation before it may be recommended for self-reporting pain intensity.

AIMS: The study aimed to determine the convergent and discriminant validity of a new digital pain assessment scale in a pediatric postoperative setting.

METHODS: The study was performed at a pediatric surgery department in southern Sweden. A total of 88 children were included, generating 716 assessments. Convergent validity was established by comparing the well-validated Colored Analogue Scale and Faces Pain Scale Revised with the electronic Faces Thermometer Scale. Pain assessments were conducted at three different time points: one before surgery, one once the participant became alert and aware, and one 30-45 min after the second time point. A p-value of 0.05 was considered statistically significant. Discriminant validity was established by comparing a potential non-painful situation with a painful situation using the electronic Faces Thermometer Scale.

RESULTS: The agreement between the scales at different time points, as well as across different ages and gender, showed a statistically significant correlation: Kendall's Tau B correlation coefficient varied between 0.61 and 0.79 at different time points. The electronic Faces Thermometer Scale was able to discriminate pain across different age groups and genders. There was a statistically significant difference between pre- and postoperative assessments, and the Clopper-Pearson proportion ranged from 0.70 to 0.90.

CONCLUSIONS: The electronic Faces Thermometer Scale provides a valid digital scale for self-report of pain within pediatric postoperative care.