A standardized questionnaire has not been established for screening or diagnostic assessment of patients with multiple chemical sensitivity (MCS) in Japan. In the US, Miller and Prihoda (1999a, b) developed a questionnaire that could be used internationally, the Quick Environment Exposure Sensitivity Inventory (QEESI©), to assist researchers and clinicians in evaluating patients and populations for chemical sensitivity. The Japanese version of QEESI©was subsequently translated by Ishikawa and Miyata (1999). The present study was performed to investigate the reliability and validity of QEESI©(Japanese version) for research purposes and for evaluation of patients with MCS in Japan. A total of 498 subjects were recruited from the general population of Miyagi prefecture, Japan. The factor structure in QEESI©was analyzed with 40 items on four subscales except for the items in ‘Masking’ using principal components analysis with Promax rotation. The results showed that 30 items on three subscales, ‘Chemical Inhalant Intolerances,’ ‘Symptom Severity,’ and ‘Life Impact’ except for ‘Other Intolerances’ were consistent with those reported for the US population by Miller and Prihoda (1999a). Cronbach’s a reliability coefficient ranged between 0.87 and 0.94 indicating high internal consistency in the 30 items on three subscales. Next, we compared the mean scores on three subscales of QEESI©in two groups: 131 self-reported MCS group who were new outpatients at the Environmental Medical Center in Kitasato Institute Hospital, and 131 members of the general population (controls) who were matched for both gender and age with the self-reported MCS group. Mean scores on each subscale for the self-reported MCS group were significantly greater than those for controls (PB < 0.001). Mean scores on all of the 30 items on three subscales for the self-reported MCS group were also significantly greater than for the controls (PB < 0.001). These findings indicated that the 30 items on three subscales in QEESI©can be used for surveys and for diagnostic assessment of patients with MCS as well as for comparative studies between patients in Japan and in other countries.

Objectives The Quick Environment Exposure Sensitivity Inventory (QEESI^©) has been used as a questionnaire to evaluate subjective symptoms of patients with multiple chemical sensitivity (MCS), also known as idiopathic environmental intolerance, in Japan. However, no cutoff value for Japanese subjects has yet been established. We designed this study to establish a cutoff value for Japanese subjects using QEESI^© for screening of MCS patients. Methods A questionnaire using the QEESI^© was administered to 103 MCS patients and 309 healthy control subjects matched for age and sex. QEESI^© scores of the two groups were compared using logistic regression analysis, receiver operating characteristic analysis, and the Mann–Whitney test. Results Cutoff values for Japanese subjects were determined for the Chemical Intolerance subscale (40), Symptom Severity subscale (20), and Life Impact subscale (10). The subjects whose scores exceeded the cutoff values in any two subscales accounted for 88.4% of the patients but only 14.5% of the controls. Conclusions Our results suggest that subjects meeting two out of three subscale criteria can be screened as “patients suffering from a low level of environmental chemicals such as MCS” in Japan.

The Quick Environmental Exposure and Sensitivity Inventory (QEESI) developed by Miller and Prihoda in the USA is used as a questionnaire for patients with multiple chemical sensitivity (MCS) in >10 countries. We developed a Japanese version of QEESI, assessed its reliability and validity, and defined original cut-off values for screening Japanese patients with MCS in 2003. Our recent study revealed that opportunities for exposure to various chemicals had increased for people in Japan, while subjective symptoms of MCS in patients had increased in severity. In this study, we considered new cut-off values that combined QEESI subscale scores based on the current situation in Japan. The questionnaire used was a Japanese version of QEESI. The survey was conducted from 2012 to 2015. Participants were 111 patients with MCS (mean age: 46 ± 20, 81% female) initially diagnosed by physicians, and 444 age- and gender-matched controls not diagnosed with MCS by doctors. The discriminatory validity of QEESI scores of patients and controls were evaluated by logistic regression and receiver operating characteristic analyses when considering interactions of the Masking Index (ongoing chemical exposure). New combined cut-off values were then set. New combined cut-off values (meeting conditions of Chemical Intolerances ≥ 30, Symptom Severity ≥ 13, and Life Impacts ≥ 17) showed high sensitivity (82.0%) and specificity (94.4%). Using new criteria when considering ongoing chemical exposure, study participants were categorized as: Very suggestive, Somewhat suggestive, Problematic, and Not suggestive. Participants classified as Very suggestive included 25 (5.6%) controls. We have set new criteria with combined cut-off values based on current Japanese conditions. Such new criteria can be used for screening and as a diagnostic aid for Japanese patients with MCS and suggest approximately 6% of the Japanese general population may be classified as “Very suggestive people with MCS”.

QEESI© (Miller and Prihoda, 1999a: Toxicology and Industrial Health, 15, 370) was applied to 498 subjects, recruited from the general population of Miyagi prefecture, Japan, who had not been diagnosed previously as having multiple chemical sensitivity (MCS) or sick building syndrome. Seventeen (3.8%) of 440 subjects who returned valid completed questionnaires were classified as having symptoms ‘very suggestive’ of MCS using the four-classification system of Miller and Prihoda (1999a). We conducted detailed telephone interviews with these 17 individuals. All were visiting local hospitals on an outpatient basis with diagnoses other than MCS and had either current or previous presumed chemical exposure. Therefore, we recommended they undergo a medical check by MCS medical experts and indoor air quality assessment. Seven subjects participated in both the medical check and indoor air quality monitoring, six subjects participated in indoor air quality monitoring only and four subjects participated in neither. The seven subjects who participated in both the medical check and monitoring were diagnosed as having MCS by the above expert physicians. In nine houses of 13 subjects who participated in indoor environmental quality (IEQ) survey, acetaldehyde (9/9), formaldehyde (8/9), total volatile compounds (TVOCs) (6/9) and paradichlorobenzene (3/9) levels were above the respective guideline values for indoor air concentrations, outlined by the Ministry of Health, Labor and Welfare of Japan and were presumed to act as factors contributing to the subjects’ hypersensitivity and onset or development of symptoms. These results suggested that there might still be a population of patients not properly diagnosed as having MCS by clinicians in Japan. Therefore, we verified the efficacy of QEESI (Japanese version) for screening of MCS patients. The results of indoor air quality analysis suggested the manifestation and deterioration of MCS in Japan might be precipitated by indoor air pollutants, such as formaldehyde, acetaldehyde, volatile compounds (VOCs) and paradichlorobenzene.