title: Performance of an item response theory-based computer adaptive test in identifying functional decline.
abstract: OBJECTIVE
  To achieve a low respondent burden and increase the responsiveness of functional measurement by using an item response theory-based computer adaptive test (CAT), the Activity Measure for Post-Acute Care (AM-PAC) CAT.
  
  
  METHODS
  Two-year prospective cohort study.
  
  
  METHODS
  Telephonic assessments from a quaternary medical center.
  
  
  METHODS
  Patients (N=311) with late-stage lung cancer (LC).
  
  
  METHODS
  Monthly assessments for up to 2 years. Disease progression was determined via record abstraction. Anchor-based responsiveness techniques were used to compare AM-PAC-CAT score changes between global rating of change (GRC) question response levels, as well as between intervals when adverse clinical events or symptom worsening did and did not occur. Distribution-based responsiveness assessments included calculation of the standardized effect size (SES) and standardized response mean (SRM).
  
  
  METHODS
  AM-PAC-CAT, symptom numerical rating scales, and a GRC.
  
  
  RESULTS
  Administration time averaged 112 seconds over 2543 interviews. AM-PAC-CAT score changes became more positive as GRC responses reflected more improved states: a lot worse (-11.62), a little worse (-1.92), the same (-.10), a little better (1.01), and a lot better (2.82). Score changes were negative when associated with adverse clinical events. The SES and SRM for score differences between 1 to 2 and 9 to 10 months prior to death were -.87 and -1.13, respectively. The minimally important difference estimate was defined by the mean CAT session SE at 2.0.
  
  
  CONCLUSIONS
  The AM-PAC-CAT imposes a low, <2-minute, respondent burden, and distribution- and anchor-based methods suggest that is moderately responsive in patients with late-stage LC.
authors: Department of Physical Medicine and Rehabilitation, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA. Cheville.andrea@mayo.edu
authors: Andrea L
authors: AL
authors: Cheville
authors: Kathleen J
authors: KJ
authors: Yost
authors: Dirk R
authors: DR
authors: Larson
authors: Katiuska
authors: K
authors: Dos Santos
authors: Megan M
authors: MM
authors: O'Byrne
authors: Megan T
authors: MT
authors: Chang
authors: Terry M
authors: TM
authors: Therneau
authors: Felix E
authors: FE
authors: Diehn
authors: Ping
authors: P
authors: Yang
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis / Q000401:mortality / Q000628:therapy*; D015331:Cohort Studies; D003266:Continuity of Patient Care; D004185:Disability Evaluation; D018450:Disease Progression; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016014:Linear Models; D008175:Lung Neoplasms / Q000175:diagnosis / Q000401:mortality / Q000628:therapy*; D008297:Male; D016347:Medical Records Systems, Computerized / Q000706:statistics & numerical data*; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods*; D015999:Multivariate Analysis; D009361:Neoplasm Invasiveness / Q000473:pathology; D009367:Neoplasm Staging; D016017:Odds Ratio; D011446:Prospective Studies; D018570:Risk Assessment; D018434:Sickness Impact Profile; D015996:Survival Rate; D013997:Time Factors