JMIR Publications

ABSTRACT

Background:

An accurate measurement of pain is required to improve its management and research. The Visual Analog Scale (VAS) on paper format has been shown to be an accurate, valid, reliable and reproducible way to measure pain intensity. However, some limitations should be considered, some of which can be implemented with the introduction of an electronic VAS version, suitable to be used both in a tablet and a smartphone.

Objective:

This study aims to validate a new method of recording pain level by comparing the traditional paper VAS with the “Pain Level” module, included in the newly designed App “Interactive Clinics”.

Methods:

A prospective observational cross-sectional study was designed. The sample consisted on 102 participants, aged 18 to 65 years old. A Force Dial algometer was employed to induce mild pressure symptoms at the participants’ thumbs. Pain was measured using a paper VAS (10 cm line) and the app. Inter-method and intra-method reliability were assessed using both Intraclass Correlation Coefficient and Bland-Altman analysis.

Results:

The inter-method reliability estimated by ICC (3,1) was 0.8588 with a 95% confidence interval of 0.8139 to 0.8961, indicating a good-reliability. The intra-method reliability estimated by ICCa(3,1) was 0.8588 with a 95% confidence interval of 0.8088 to 0.8976 also indicating a good-reliability. Bland-Altman analysis showed a difference (SD) of 0.175 (0.49) and limits of agreement ranged from -0.79 to 1.14.

Conclusions:

The “Pain Level” module is highly reliable and interchangeable with paper VAS version. This tool could potentially help clinicians and researchers to precisely asses pain in a simple, economical way with the use of a ubiquitous technology. Clinical Trial: This study was approved by the Comitè d’Ètica en Recerca from U. Vic – UCC, number 48/2018.