title: Distribution-based estimates of minimal important difference for hospital anxiety and depression scale and impact of event scale-revised in survivors of acute respiratory failure.
abstract: This study will estimate distribution-based minimal important difference (MID) for the Hospital Anxiety and Depression Scale anxiety (HADS-A) and depression (HADS-D) subscales, and the Impact of Event Scale-Revised (IES-R) in survivors of acute respiratory failure (ARF).
  
  
  
  Secondary analyses of data from two US and three UK studies of ARF survivors (total N=1223). HADS-D and HADS-A were used to assess depression and anxiety symptoms. IES-R assessed post-traumatic stress disorder symptoms. Standard error of measurement, minimal detectable change90, 0.5 standard deviation (S.D.), and 0.2 S.D. were used to estimate MID for the combined sample, by studies, 6- and 12-month follow-ups, country and mental health condition.
  
  
  
  Overall, MID estimates converged to 2.0-2.5 for the HADS-A, 1.9-2.3 for the HADS-D and 0.17-0.18 for the IES-R. MID estimates were comparable across studies, follow-up, country and mental health condition.
  
  
  
  Among ARF survivors, 2.0-2.5 is a reasonable range for the MID for both HADS subscales, and 0.2 is reasonable for IES-R. Until anchor-based MIDs for these instruments are available, these distribution-based estimates can help researchers plan future studies and interpret the clinical importance of findings in ARF patient populations.
authors.affiliation: Department of Health Policy and Management, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA. Electronic address: kchan10@jhu.edu.
authors.forename: Kitty S
authors.initials: KS
authors.lastname: Chan
authors.affiliation: Outcomes After Critical Illness and Surgery (OACIS) Group, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Lisa
authors.initials: L
authors.lastname: Aronson Friedman
authors.affiliation: Outcomes After Critical Illness and Surgery (OACIS) Group, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Mental Health, Johns Hopkins University Bloomberg, School of Public Health, Baltimore, MD.
authors.forename: O Joseph
authors.initials: OJ
authors.lastname: Bienvenu
authors.affiliation: Outcomes After Critical Illness and Surgery (OACIS) Group, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Victor D
authors.initials: VD
authors.lastname: Dinglas
authors.affiliation: Department of Critical Care Medicine, Sunnybrook Health Sciences Centre, Toronto, ON, Canada; Department of Anesthesia, University of Toronto, Toronto, ON, Canada.
authors.forename: Brian H
authors.initials: BH
authors.lastname: Cuthbertson
authors.affiliation: Glenfield Hospital, Leicester, UK.
authors.forename: Richard
authors.initials: R
authors.lastname: Porter
authors.affiliation: University of Liverpool, Liverpool, UK.
authors.forename: Christina
authors.initials: C
authors.lastname: Jones
authors.affiliation: Department of Medicine, Pulmonary and Critical Care Division, Intermountain Medical Center, Murray, UT, USA; Center for Humanizing Critical Care, Intermountain Health Care, Murray, UT, USA; Psychology Department and Neuroscience Center, Brigham Young University, Provo, UT, USA.
authors.forename: Ramona O
authors.initials: RO
authors.lastname: Hopkins
authors.affiliation: Outcomes After Critical Illness and Surgery (OACIS) Group, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Dale M
authors.initials: DM
authors.lastname: Needham
mesh_terms: D000328:Adult; D001007:Anxiety / Q000175:diagnosis*; D003627:Data Interpretation, Statistical; D003863:Depression / Q000175:diagnosis*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data*; D012131:Respiratory Insufficiency / Q000523:psychology*; D013313:Stress Disorders, Post-Traumatic / Q000175:diagnosis*; D017741:Survivors / Q000523:psychology*
keywords: Acute respiratory failure; Hospital anxiety and depression scale; Impact of event scale-revised; Minimal important difference