title: Comparing non-specific physical symptoms in environmentally sensitive patients: prevalence, duration, functional status and illness behavior.
abstract: OBJECTIVE
  Little is known about the potential clinical relevance of non-specific physical symptoms (NSPS) reported by patients with self-reported environmental sensitivities. This study aimed to assess NSPS in people with general environmental sensitivity (GES) and idiopathic environmental intolerance attributed to electromagnetic fields (IEI-EMF) and to determine differences in functional status and illness behavior.
  
  
  METHODS
  An epidemiological study was conducted in the Netherlands, combining self-administered questionnaires with the electronic medical records of the respondents as registered by general practitioners. Analyses included n=5789 registered adult (≥18 years) patients, comprising 5073 non-sensitive (NS) individuals, 514 in the GES group and 202 in the IEI-EMF group.
  
  
  RESULTS
  Participants with GES were about twice as likely to consult alternative therapy compared to non-sensitive individuals; those with IEI-EMF were more than three times as likely. Moreover, there was a higher prevalence of symptoms and medication prescriptions and longer symptom duration among people with sensitivities. Increasing number and duration of self-reported NSPS were associated with functional impairment, illness behavior, negative symptom perceptions and prevalence of GP-registered NSPS in the examined groups.
  
  
  CONCLUSIONS
  Even after adjustment for medical and psychiatric morbidity, environmentally sensitive individuals experience poorer health, increased illness behavior and more severe NSPS. The number and duration of self-reported NSPS are important components of symptom severity and are associated with characteristics similar to those of NSPS in primary care. The substantial overlap between the sensitive groups strengthens the notion that different types of sensitivities might be part of one, broader environmental illness.
authors.affiliation: Institute for Risk Assessment Sciences (IRAS), Utrecht University, Utrecht, The Netherlands; National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands. Electronic address: christos.baliatsas@rivm.nl.
authors.forename: Christos
authors.initials: C
authors.lastname: Baliatsas
authors.affiliation: National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands.
authors.forename: Irene
authors.initials: I
authors.lastname: van Kamp
authors.affiliation: Netherlands Institute for Health Services Research (NIVEL), Utrecht, The Netherlands.
authors.forename: Mariette
authors.initials: M
authors.lastname: Hooiveld
authors.affiliation: Netherlands Institute for Health Services Research (NIVEL), Utrecht, The Netherlands.
authors.forename: Joris
authors.initials: J
authors.lastname: Yzermans
authors.affiliation: Institute for Risk Assessment Sciences (IRAS), Utrecht University, Utrecht, The Netherlands; National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands.
authors.forename: Erik
authors.initials: E
authors.lastname: Lebret
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D004574:Electromagnetic Fields; D055590:Electromagnetic Phenomena; D018876:Environmental Illness / Q000453:epidemiology* / Q000523:psychology*; D005260:Female; D006801:Humans; D055809:Illness Behavior; D008297:Male; D008875:Middle Aged; D018777:Multiple Chemical Sensitivity / Q000453:epidemiology / Q000523:psychology; D009426:Netherlands / Q000453:epidemiology; D010465:Perception; D015995:Prevalence; D012803:Sick Role; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: Electromagnetic hypersensitivity; Environmental sensitivity; IEI-EMF; Idiopathic environmental intolerance; Medically unexplained symptoms; Primary care