The Brief Environmental Exposure and Sensitivity Inventory (BREESI): an international validation study

Background Chemical intolerance (CI) is a condition that may result in multisystem symptoms triggered by low levels of exposure to xenobiotics such as chemical inhalants, foods, and/or drugs. The population prevalence of self-reported chemical intolerance is estimated to be between 4 and 25% across several countries. Clinicians and researchers require a brief, practical screening tool for identifying chemical intolerance. Objectives We investigated the validity of a three-item screening questionnaire for CI, the Brief Environmental Exposure and Sensitivity Inventory (BREESI). The internationally validated, and widely used 50-item Quick Environmental Exposure and Sensitivity Inventory (QEESI) was used as the reference standard. Methods Five thousand individuals ( n = 1000 in each of five countries: the US, Japan, Italy, Mexico, and India) responded to both the QEESI and the BREESI using an online research survey platform. We determined the statistical performance metrics for the BREESI, comparing the number of items chosen on the BREESI with QEESI scores for chemical intolerance. Logistic regression was used to determine the likelihood of chemical intolerance based on endorsing 0, 1, 2, or 3 items on the BREESI. We report the BREESI's sensitivity and specificity, positive and negative predictive values, and positive and negative likelihood ratios. Results Compared to the QEESI reference standard, the BREESI had excellent sensitivity, specificity, positive and negative likelihood ratios, and positive and negative predictive values for chemical intolerance in all countries except than in Japan, the negative predictive value was poor. Notwithstanding, logistic regression curves show that in all of the countries, for each one-unit increase in the number of BREESI items, there is a 4- to 5-fold increase in the odds of CI. Discussion This study confirms the results of two recently published validation papers in the US. The BREESI performs well as a screening tool for chemical intolerance. It is a practical screening tool for researchers, clinicians, and epidemiologists seeking to understand and address this important and prevalent condition.