title: Heart rate reactivity and current post-traumatic stress disorder when data are missing.
abstract: OBJECTIVE
  This study demonstrates that auxiliary and exclusion criteria variables increase the effectiveness of missing imputation in correcting underestimation of physiologic reactivity in relation to post-traumatic stress disorder (PTSD) caused by deleting cases with missing physiologic data.
  
  
  METHODS
  This study used data from survivors of the 1995 Oklahoma City bombing and imputed missing heart rate data using auxiliary and exclusion criteria variables. Logistic regression was used to examine heart rate reactivity in relation to current PTSD.
  
  
  RESULTS
  Of 113 survivors who participated in the bombing study's 7-year follow-up interview, 42 (37%) had missing data on heart rate reactivity due to exclusion criteria (medical illness or use of cardiovascular or psychotropic medications) or non-participation. Logistic regression results based on imputed heart rate data using exclusion criteria and auxiliary (the presence of any current PTSD arousal symptoms) variables showed that survivors with current bombing-related PTSD had significantly higher heart rates at baseline and recovered more slowly back to baseline heart rate during resting periods than survivors without current PTSD, while results based on complete cases failed to show significant correlations between current PTSD and heart rates at any assessment points.
  
  
  CONCLUSIONS
  Suggested methods yielded an otherwise undetectable link between physiology and current PTSD.
authors.affiliation: Department of Psychiatry and Behavioral Sciences, The University of Oklahoma of Health Sciences Center, Oklahoma City, Oklahoma 73103, USA. hattie-jeon-slaughter@ouhsc.edu
authors.forename: Haekyung
authors.initials: H
authors.lastname: Jeon-Slaughter
authors.forename: Phebe
authors.initials: P
authors.lastname: Tucker
authors.forename: Betty
authors.initials: B
authors.lastname: Pfefferbaum
authors.forename: Carol S
authors.initials: CS
authors.lastname: North
authors.forename: Bernardo Borba
authors.initials: BB
authors.lastname: de Andrade
authors.forename: Barbara
authors.initials: B
authors.lastname: Neas
mesh_terms: D003625:Data Collection / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009825:Oklahoma; D013313:Stress Disorders, Post-Traumatic / Q000503:physiopathology*; D017741:Survivors / Q000706:statistics & numerical data*