The Environmental Symptom-Attribution Scale: Metric properties and normative data

The objective was to develop, metrically evaluate and establish normative data for the Environmental Symptom-Attribution Scale (ESAS), which is a questionnaire-based instrument for quantifying degree to which health symptoms are attributed to specific environmental exposures and sources. Data were used from 3406 individuals who took part in the Västerbotten Environmental Health Study in Sweden. The responders constitute a random sample, aged 18-79 years. They responded to the ESAS and to questions about physician-based diagnoses for evaluation of concurrent validity of the ESAS. Four dimensions of the ESAS were identified, constituting subscales: the Odorous/Pungent, Building-Related, Sound, and Electromagnetic Field Subscales. A Global Scale is available as well. In general, the distributions of the scores on the scales were positively skewed and leptokurtic in shape. The results demonstrate good reliability and concurrent validity of all five ESAS scales. Percentiles were obtained as normative data. Examples of use of the ESAS applied on individuals are provided. The favorable metric properties of the ESAS and its rapid administration suggest that it is useful for assessment in clinical and epidemiological settings.