Intrarater and Interrater Reliability of Infrared Image Analysis of Forearm Acupoints before and after Moxibustion

Abstract

The objective of this study was to determine the intrarater and interrater reliabilities of infrared image analysis of forearm acupoints before and after moxibustion. In this work, infrared images of acupoints in the forearm of 20 volunteers (M/F, 10/10) were collected prior to and after moxibustion by infrared thermography (IRT). Two trained raters performed the analysis of infrared images in two different periods at a one-week interval. The intraclass correlation coefficient (ICC) was calculated to determine the intrarater and interrater reliabilities. With regard to the intrarater reliability, ICC values were between 0.758 and 0.994 (substantial to excellent). For the interrater reliability, ICC values ranged from 0.707 to 0.964 (moderate to excellent). Given that the intrarater and interrater reliability levels show excellent concordance, IRT could be a reliable tool to monitor the temperature change of forearm acupoints induced by moxibustion.

Figure 1

Measurement procedure.

Figure 2

Distribution of the 4 ROIs in the thermographic images of the forearm before and after moxibustion. (a) Before moxibustion at LU 5; (b) after moxibustion at LU 5 for 10 min; (c) before moxibustion at HT 3; and (d) after moxibustion at HT 3 for 10 min.

Figure 3

Bland–Altman plot for intrarater agreement between two sets of the temperature values, 7.18% of all readings taken fell outside the 95% agreement limits.

Figure 4

Bland–Altman plot for interrater agreement between two sets of the temperature values, 6.87% of all readings taken fell outside the 95% agreement limits.

Figure 5

Bland–Altman plot for intrarater agreement between two sets of temperature differences (ΔT) after moxibustion at LU 5, 5.00% of all readings taken fell outside the 95% agreement limits.

Figure 6

Bland–Altman plot for interrater agreement between two sets of temperature differences (ΔT) after moxibustion at LU 5, 6.25% of all readings taken fell outside the 95% agreement limits.

Figure 7

Bland–Altman plot for intrarater agreement between two sets of temperature differences (ΔT) after moxibustion at HT 3, 6.87% of all readings taken fell outside the 95% agreement limits.

Figure 8

Bland–Altman plot for interrater agreement between two sets of temperature differences (ΔT) after moxibustion at HT 3, 5.00% of all readings taken fell outside the 95% agreement limits.