title: Covariation of physical and mental symptoms across illnesses: results of a factor analytic study.
abstract: OBJECTIVE
  Chronic illnesses are associated with reports of symptoms, problems, and dysfunction along multiple dimensions. To determine if the dimensionality is disease-specific and whether physical and emotional symptoms are concomitant and inseparable aspects of the illness experience, we present a factor analysis of symptom and problem reports from five different chronic conditions.
  
  
  METHODS
  People with five different conditions participated in this study: multiple sclerosis (MS) (n = 263), non-insulin-dependent diabetes mellitus (n = 420), nonhead nonneck injury trauma (n = 852), and a group of terminal patients comprised of acquired immune deficiency syndrome (AIDS) (n = 99) and cancer (n = 74) patients. Participants were asked to complete the Quality of Well-Being Scale (QWB) and symptom items from the QWB were factor analyzed.
  
  
  RESULTS
  Both within each condition and across conditions, two factors accounted for the majority of the explained variance and could be described as an Observable Limitations factor and a Subjective Symptoms factor.
  
  
  CONCLUSIONS
  Our factor analyses suggest that physical and emotional symptoms covary and are common to different types of illness.
authors.affiliation: Frontier Science & Technology Research Foundation, Inc., Chestnut Hill, MA 02467, USA.
authors.forename: C E
authors.initials: CE
authors.lastname: Schwartz
authors.forename: R M
authors.initials: RM
authors.lastname: Kaplan
authors.forename: J P
authors.initials: JP
authors.lastname: Anderson
authors.forename: T
authors.initials: T
authors.lastname: Holbrook
authors.forename: M W
authors.initials: MW
authors.lastname: Genderson
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000523:psychology*; D000328:Adult; D002170:Canada; D002908:Chronic Disease; D003924:Diabetes Mellitus, Type 2 / Q000523:psychology*; D005163:Factor Analysis, Statistical; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D008603:Mental Health; D008875:Middle Aged; D015337:Multicenter Studies as Topic; D009103:Multiple Sclerosis / Q000523:psychology*; D009369:Neoplasms / Q000523:psychology*; D011795:Surveys and Questionnaires; D015599:Trauma Severity Indices; D014481:United States; D014947:Wounds and Injuries / Q000523:psychology*