Environmental Sensitivities: Prevalence of Major Symptoms in a Referral Center: The Nova Scotia Environmental Sensitivities Research Center Study

Environmental Health Perspectives, Feb, 2001 by Michel R. Joffres, Tim Williams, Brenda Sabo, Roy A. Fox

Some of the high scores among women after exposure such as "trouble seeing at night" and "bruising easily" were not expected. The next steps in the analysis of these data will be to conduct factor analyses to see if there are any specific subgroups. Multivariate analysis will be used to investigate associations between symptom occurrence, scores, and other variables available in this data set. In a separate preliminary factor analysis, a single factor explained a high proportion of variance compared with all the other factors, suggesting a certain homogeneity of this group of individuals.

This study has a few limitations. The relatively low response rate (47%) in this usually committed group was not anticipated and limited generalizations. The response rate might be explained partly by negative media attention aimed at the center and by a postal strike, both of which coincided with the mailing of surveys. Follow-up calls to recipients elicited the following most frequently cited reasons for failing to answer the questionnaire: difficulty answering some of the questions, length of the questionnaire, busy lifestyle, or the taxing nature of the questionnaire. Because this population experiences a high level of cognitive difficulties, a long questionnaire might have been perceived as too taxing on the already low energy level of some of these individuals. Pilot testing had not revealed any major problem in this area, so the length of the questionnaire had not been reduced. Because basic demographic data had been collected on all individuals, comparison of nonrespondents with respondents found no statistically significant differences in age or sex distribution between these groups.

Issues around bias due to self-referral and differential diagnosis were limited because only Nova Scotia physicians have referred patients to the center. After examination, about 9% of referrals received a diagnosis other than ES. These 34 individuals were removed from analyses. Because we are the only referral center in Nova Scotia, we can also assume that our patient population is fairly representative of the ES population. Nevertheless, it is important to recognize that, as yet, no conclusive test exists to confirm the diagnosis of ES and that a diagnosis of ES remains clinical, based on limited criteria (16,21).

A priori labeling of these symptoms as psychogenic has done tremendous harm: It has hindered the ability of affected individuals to seek help, and also the amount of research conducted (7,28,30). It is time to recognize that we cannot separate the psyche from the physical dimensions of the human being, and that we must understand and support ES sufferers. It is vital not to wait for answers on definitions, etiology, and pathophysiology before we protect individuals with existing recommendations (31,32). This phenomenon is not new (33); it affects quality of life, disables, and creates major human and economic losses. Although many individuals return to a healthy and productive life, varying degrees of sensitivity remain. Strategies that look at multiple aspects of individuals' lives have been successful in reintegrating individuals into a fulfilling social and work environment. Attitudes of treating physicians must change to reflect and accept the reality of these experiences as multifactorial, where psychological and physical aspects are part of the problem and the solution.