JMIR Publications

ABSTRACT

Background:

Measuring pain on mobile devices using classic unidimensional pain scales like visual analogue scale (VAS), numerical rating scale (NRS), and face pain scale (FPS) was proved to be reliable and valid. However, most classic pain scales were designed in monotone color, which looks less appealing on touch screens. Colorful pain scales with a good design might be more welcomed by mobile device users. Emojis are pictographs that are typically presented in a colorful form. Conformed to the Unicode standard, emoji possess the power of standardization across platforms and they are popular among mobile device users. Thousands of emojis have been developed and certain emoji faces might be combined to measure pain. However, which emojis sequence can best reflect levels of pain needs to be studied.

Objective:

This study was designed to develop an emoji faces pain scale (emoji-FPS) as well as to check its reliability, validity, and preference in adult patients who receive surgery.

Methods:

A modified Delphi technique with two rounds of online surveys was applied to obtain panelists’ consensus on the sequence of emojis that can best represent six levels of pain. Then, a prospective cohort of patients scheduled to receive perianal surgery were recruited in one center and were asked to complete an online questionnaire on a mobile device at five time points (before surgery [T1], wake up after surgery [T2], four hours after surgery [T3], the second day after surgery [T4], and fifteen minutes after T4 [T5]). Four well validated pain scales (NRS, VAS, Wong-Baker FACES® pain rating scale [Wong-Baker FACES], and Faces Pain Scale-Revised [FPS-R]) were included in the questionnaire.

Results:

After two rounds of surveys on 40 panelists, an emoji-FPS of ????, ????, ????, ☹️, ????, and ???? was finally determined to represent six pain levels from “No Hurt” to “Hurst Worst”. For validation, 300 patients underwent scheduled perianal surgery were recruited and 299 were analyzed, mean (SD) age of whom was 38.5 (10.5) years and 106 (35.5%) were women. For concurrent validity, Emoji-FPS was highly correlated with four reference scales with Spearman correlation coefficient ρ ranging from 0.91 to 0.95. Excellent agreements were observed between four versions of Emoji-FPS (on iOS, Android, Microsoft platforms and Openmoji) with weighted Kappa coefficients ranging from 0.96 to 0.97. For discriminant validity, patients’ mean preoperative Emoji-FPS score (T1) was significantly higher than postoperative Emoji-FPS score (T4) with a difference of 1.4 (95% CI, 1.3-1.6, P <.001). For test-retest reliability, Emoji-FPS scores measured at T4 and T5 were highly correlated with ρ of 0.91. Emoji-FPS was mostly preferred by patients, followed by Wong-Baker FACES, FPS-R, NRS, and VAS.

Conclusions:

It’s feasible to apply the newly developed Emoji-FPS in adult surgery patients. Clinical Trial: Registration number：ChiCTR2100051366