Development of corrected perceptual strain index (CPeSI) with higher validity

<h2>Abstract</h2> Incorporating age and BMI in the equation of PeSI can enhance the accuracy and validity of this index. Therefore, the aim of this study was to develop the Corrected Perceptual Strain Index (CPeSI) and validate its use as a measure of perceptual strain. 194 Iranian male employees participated in this study. In the first step, data related to the demographic characteristics of the person was gathered. In the next step, the subjects were asked to perform the routine work, and their tympanic temperature and environmental parameters were measured after 90 min. Moreover, the subjects are asked to state their thermal sensation and perceived exertion. In the final step, the new index was developed by this data using structural equation modeling. The impact of these parameters on tympanic temperature was determined and used to develop a new equation based on their normalized values between zero and one. The impact coefficients of the variables of age, body mass index, rating of perceived exertion, and thermal sensation were equal to 0.142, 0.171, 0.773, and 0.561, respectively. To categorize the total score of the index, cut-off points of 7.95, 9.89, and 11.69 were obtained by ROC analysis. The results showed that indices of perceptual strain index (PeSI) and corrected perceptual strain index (CPeSI) justified 65 and 71 percent of the variations in the body temperature, respectively. Overall, based on the results of this field study it can be concluded that the newly developed CPeSI index, which takes into account the influences of age and BMI, is a more reliable and valid measure for assessing perceptual strain compared to the older index.