A multiple center study of Multiple Chemical Sensitivity syndrome

The lack of widely accepted, standardized, clinical and epidemiologic crite ria for Multiple Chemical Sensitivity syndrome has led to confusion about t he identification of the condition and has slowed pertinent research. In th is article, the authors evaluated the psychometric properties of 2 sets of clinical/epidemiologic criteria for Multiple Chemical Sensitivity syndrome. In this cross-sectional survey of 1,166 patients who visited outpatient oc cupational, otolaryngology, allergy, and clinical ecological clinics, the a uthors used the aforementioned sets of criteria to (a) estimate the prevale nce of the syndrome in these varied samples and (b) compare the current dia gnostic practices of traditional physician specialists with those of clinic al ecologists. The authors used a patient-completed questionnaire to assess the medical, psychosocial, and psychological status of patients who report ed multiple chemical sensitivities. This approach enabled the formulation o f 6 domains, which represented commonly observed characteristics of the syn drome. The authors used a physician-completed questionnaire to collect diag noses of Multiple Chemical Sensitivity syndrome and other medical condition s. Domains, which were operationalized by the questionnaire and comprised t he 2 sets of criteria for identification of the Multiple Chemical Sensitivi ty syndrome, had test-retest reliabilities that exceeded .75 and estimates of internal consistency that ranged between .59 and .94. Evidence of constr uct and face validity was considered acceptable. The overall clinic-based p revalences of Multiple Chemical Sensitivity syndrome, based on 6 and 4 doma ins, were 7% and 23%, respectively. Regardless of the identifying set of cr iteria used, physicians' diagnoses had relatively low sensitivities (range = 6-50%) and relatively high specificities (range = 82-99%). The study data suggested that the domains operationalized by the questionnaire had reason able psychometric characteristics. Study data also support the fact that Mu ltiple Chemical Sensitivity syndrome is often overlooked-even by those phys icians who treat it most frequently-and that use of both sets of objective criteria for identifying the syndrome would greatly improve the sensitivity of physician diagnoses.