A multiple center study of multiple chemical sensitivity syndrome

Area of Science:

• Environmental Health
• Clinical Epidemiology
• Psychometrics

Background:

• Lack of standardized criteria for Multiple Chemical Sensitivity syndrome (MCS) hinders research and diagnosis.
• Clinical ecologists and traditional specialists have differing diagnostic practices for MCS.
• Patient-reported symptoms and physician diagnoses are key data points for MCS assessment.

Purpose of the Study:

• To evaluate the psychometric properties of two sets of clinical/epidemiologic criteria for MCS.
• To estimate the prevalence of MCS in diverse outpatient clinic populations.
• To compare diagnostic practices between traditional physicians and clinical ecologists.

Main Methods:

• Cross-sectional survey of 1,166 patients across multiple clinic types.
• Utilized patient-completed questionnaires assessing medical, psychosocial, and psychological status.
• Developed and validated criteria based on 6 domains of commonly observed MCS characteristics.

Main Results:

• The developed criteria demonstrated good test-retest reliability (> .75) and internal consistency (.59–.94).
• Clinic-based prevalence estimates for MCS were 7% (6 domains) and 23% (4 domains).
• Physician diagnoses showed low sensitivity (6–50%) but high specificity (82–99%) for MCS.

Conclusions:

• The questionnaire-operationalized domains possess acceptable psychometric properties for identifying MCS.
• MCS is frequently underdiagnosed, even by specialists treating the condition.
• Objective criteria sets are crucial for enhancing the sensitivity of physician diagnoses for MCS.