title: Assessment of response shift using two structural equation modeling techniques.
abstract: OBJECTIVE
  To identify response shift using two structural equation modeling (SEM) techniques.
  
  
  METHODS
  Hypertensive patients (n = 909) with coronary artery disease (CAD) completed SF-36 surveys at both baseline and 1-year follow-up. Response shift was identified using Oort and Schmitt SEM techniques. The type of response shift linked to changes in various parameters of the SEM measurement model is defined differently for both SEM approaches. Effect sizes were calculated for the impact of response shift on the change of SF-36 domain scores when using the Oort approach.
  
  
  RESULTS
  Both Oort and Schmitt SEM approaches identified response shift only in the SF-36 physical functioning (PF) scale. The effect size of recalibration on the change of PF domain scores when using the Oort approach was -0.12.
  
  
  CONCLUSIONS
  This study showed that hypertensive patients with CAD experienced a response shift over a 1-year period. Both the SEM approaches identified response shift (uniform recalibration using the Oort approach and recalibration using the Schmitt approach); however, both approaches use different parameters to define and test response shift. We found that either the variation in analytic methods or the sample used may influence the identification and type of response shift.
authors.affiliation: South College, School of Pharmacy, 400 Goodys Lane, Knoxville, TN 37922, USA. pgandhi@southcollegetn.edu
authors.forename: Pranav K
authors.initials: PK
authors.lastname: Gandhi
authors.forename: L Douglas
authors.initials: LD
authors.lastname: Ried
authors.forename: I-Chan
authors.initials: IC
authors.lastname: Huang
authors.forename: Carole L
authors.initials: CL
authors.lastname: Kimberlin
authors.forename: Teresa L
authors.initials: TL
authors.lastname: Kauf
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D003324:Coronary Artery Disease / Q000523:psychology; D005163:Factor Analysis, Statistical; D005260:Female; D005500:Follow-Up Studies; D006304:Health Status; D006306:Health Surveys; D006801:Humans; D006973:Hypertension / Q000523:psychology; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D011788:Quality of Life; D011795:Surveys and Questionnaires; D016896:Treatment Outcome