title: Prospective impact of illness uncertainty on outcomes in chronic lung disease.
abstract: OBJECTIVE
  To determine which aspect of illness uncertainty (i.e., ambiguity or complexity) has a stronger association with psychological and clinical outcomes over a 2-year period among individuals with a genetic subtype of chronic obstructive pulmonary disease (COPD). Ambiguity reflects uncertainty about physical cues and symptoms, and complexity reflects uncertainty about treatment and the medical system.
  
  
  METHODS
  Four-hundred and 7 individuals with alpha-1 antitrypsin deficiency-associated COPD completed questionnaires at baseline, 1- and 2-year follow-up. Uncertainty was measured using the Mishel Uncertainty in Illness Scale. Outcomes were measured using the Hospital Anxiety and Depression Scale, St. George's Respiratory Questionnaire, and MMRC Dyspnea Scale. Ambiguity and complexity were examined as predictors of depressive symptoms, anxiety, quality of life, and breathlessness using linear mixed models adjusting for demographic and health characteristics.
  
  
  RESULTS
  Ambiguity was associated with more depressive symptoms (b = 0.09, SE = 0.02, p < .001) and anxiety (b = 0.13, SE = 0.02, p < .001), worse quality of life (b = 0.57, SE = 0.10, p < .001), and more breathlessness (b = 0.02, SE = 0.006, p < .001). Complexity did not have an independent effect on any outcome. Interactions between ambiguity and time since diagnosis were not statistically significant.
  
  
  CONCLUSIONS
  Ambiguity was prospectively associated with worse mood, quality of life, and breathlessness. Thus, ambiguity should be targeted in psychosocial interventions. Time since diagnosis did not affect the association between ambiguity and outcomes, suggesting that the impact of ambiguity is equally strong throughout the course of COPD.
authors.affiliation: Department of Psychiatry.
authors.forename: Karin F
authors.initials: KF
authors.lastname: Hoth
authors.forename: Frederick S
authors.initials: FS
authors.lastname: Wamboldt
authors.forename: Matthew
authors.initials: M
authors.lastname: Strand
authors.forename: Dee W
authors.initials: DW
authors.lastname: Ford
authors.forename: Robert A
authors.initials: RA
authors.lastname: Sandhaus
authors.forename: Charlie
authors.initials: C
authors.lastname: Strange
authors.forename: David B
authors.initials: DB
authors.lastname: Bekelman
authors.forename: Kristen E
authors.initials: KE
authors.lastname: Holm
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001007:Anxiety / Q000175:diagnosis; D003863:Depression / Q000175:diagnosis; D004417:Dyspnea / Q000175:diagnosis; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011569:Psychiatric Status Rating Scales; D029424:Pulmonary Disease, Chronic Obstructive / Q000235:genetics* / Q000523:psychology*; D011788:Quality of Life; D011795:Surveys and Questionnaires; D035501:Uncertainty; D019896:alpha 1-Antitrypsin Deficiency / Q000150:complications*