TY - JOUR T1 - Letting the CAT out of the bag: Comparing computer adaptive tests and an 11-item short form of the Roland-Morris Disability Questionnaire JF - Spine Y1 - 2008 A1 - Cook, K. F. A1 - Choi, S. W. A1 - Crane, P. K. A1 - Deyo, R. A. A1 - Johnson, K. L. A1 - Amtmann, D. KW - *Disability Evaluation KW - *Health Status Indicators KW - Adult KW - Aged KW - Aged, 80 and over KW - Back Pain/*diagnosis/psychology KW - Calibration KW - Computer Simulation KW - Diagnosis, Computer-Assisted/*standards KW - Humans KW - Middle Aged KW - Models, Psychological KW - Predictive Value of Tests KW - Questionnaires/*standards KW - Reproducibility of Results AB - STUDY DESIGN: A post hoc simulation of a computer adaptive administration of the items of a modified version of the Roland-Morris Disability Questionnaire. OBJECTIVE: To evaluate the effectiveness of adaptive administration of back pain-related disability items compared with a fixed 11-item short form. SUMMARY OF BACKGROUND DATA: Short form versions of the Roland-Morris Disability Questionnaire have been developed. An alternative to paper-and-pencil short forms is to administer items adaptively so that items are presented based on a person's responses to previous items. Theoretically, this allows precise estimation of back pain disability with administration of only a few items. MATERIALS AND METHODS: Data were gathered from 2 previously conducted studies of persons with back pain. An item response theory model was used to calibrate scores based on all items, items of a paper-and-pencil short form, and several computer adaptive tests (CATs). RESULTS: Correlations between each CAT condition and scores based on a 23-item version of the Roland-Morris Disability Questionnaire ranged from 0.93 to 0.98. Compared with an 11-item short form, an 11-item CAT produced scores that were significantly more highly correlated with scores based on the 23-item scale. CATs with even fewer items also produced scores that were highly correlated with scores based on all items. For example, scores from a 5-item CAT had a correlation of 0.93 with full scale scores. Seven- and 9-item CATs correlated at 0.95 and 0.97, respectively. A CAT with a standard-error-based stopping rule produced scores that correlated at 0.95 with full scale scores. CONCLUSION: A CAT-based back pain-related disability measure may be a valuable tool for use in clinical and research contexts. Use of CAT for other common measures in back pain research, such as other functional scales or measures of psychological distress, may offer similar advantages. VL - 33 SN - 1528-1159 (Electronic) N1 - Cook, Karon FChoi, Seung WCrane, Paul KDeyo, Richard AJohnson, Kurt LAmtmann, Dagmar5 P60-AR48093/AR/United States NIAMS5U01AR052171-03/AR/United States NIAMSComparative StudyResearch Support, N.I.H., ExtramuralUnited StatesSpineSpine. 2008 May 20;33(12):1378-83. ER -