Replenishing a computerized adaptive test of patient-reported daily activity functioning.
OBJECTIVE
Computerized adaptive testing (CAT) item banks may need to be updated, but before new items can be added, they must be linked to the previous CAT. The purpose of this study was to evaluate 41 pretest items prior to including them into an operational CAT.


METHODS
We recruited 6,882 patients with spine, lower extremity, upper extremity, and nonorthopedic impairments who received outpatient rehabilitation in one of 147 clinics across 13 states of the USA. Forty-one new Daily Activity (DA) items were administered along with the Activity Measure for Post-Acute Care Daily Activity CAT (DA-CAT-1) in five separate waves. We compared the scoring consistency with the full item bank, test information function (TIF), person standard errors (SEs), and content range of the DA-CAT-1 to the new CAT (DA-CAT-2) with the pretest items by real data simulations.


RESULTS
We retained 29 of the 41 pretest items. Scores from the DA-CAT-2 were more consistent (ICC = 0.90 versus 0.96) than DA-CAT-1 when compared with the full item bank. TIF and person SEs were improved for persons with higher levels of DA functioning, and ceiling effects were reduced from 16.1% to 6.1%.


CONCLUSIONS
Item response theory and online calibration methods were valuable in improving the DA-CAT.
Haley
Stephen M
SM
Boston University School of Public Health, Boston, MA, USA. smhaley@bu.edu
Ni
Pengsheng
P
Jette
Alan M
AM
Tao
Wei
W
Moed
Richard
R
Meyers
Doug
D
Ludlow
Larry H
LH
D000203:Activities of Daily Living; D000328:Adult; D000368:Aged; D015331:Cohort Studies; D003194:Computer-Assisted Instruction; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care / Q000379:methods*; D011795:Surveys and Questionnaires; D014584:User-Computer Interface