%0 Journal Article %J Journal of Rheumatology %D 2009 %T Progress in assessing physical function in arthritis: PROMIS short forms and computerized adaptive testing %A Fries, J.F. %A Cella, D. %A Rose, M. %A Krishnan, E. %A Bruce, B. %K *Disability Evaluation %K *Outcome Assessment (Health Care) %K Arthritis/diagnosis/*physiopathology %K Health Surveys %K Humans %K Prognosis %K Reproducibility of Results %X OBJECTIVE: Assessing self-reported physical function/disability with the Health Assessment Questionnaire Disability Index (HAQ) and other instruments has become central in arthritis research. Item response theory (IRT) and computerized adaptive testing (CAT) techniques can increase reliability and statistical power. IRT-based instruments can improve measurement precision substantially over a wider range of disease severity. These modern methods were applied and the magnitude of improvement was estimated. METHODS: A 199-item physical function/disability item bank was developed by distilling 1865 items to 124, including Legacy Health Assessment Questionnaire (HAQ) and Physical Function-10 items, and improving precision through qualitative and quantitative evaluation in over 21,000 subjects, which included about 1500 patients with rheumatoid arthritis and osteoarthritis. Four new instruments, (A) Patient-Reported Outcomes Measurement Information (PROMIS) HAQ, which evolved from the original (Legacy) HAQ; (B) "best" PROMIS 10; (C) 20-item static (short) forms; and (D) simulated PROMIS CAT, which sequentially selected the most informative item, were compared with the HAQ. RESULTS: Online and mailed administration modes yielded similar item and domain scores. The HAQ and PROMIS HAQ 20-item scales yielded greater information content versus other scales in patients with more severe disease. The "best" PROMIS 20-item scale outperformed the other 20-item static forms over a broad range of 4 standard deviations. The 10-item simulated PROMIS CAT outperformed all other forms. CONCLUSION: Improved items and instruments yielded better information. The PROMIS HAQ is currently available and considered validated. The new PROMIS short forms, after validation, are likely to represent further improvement. CAT-based physical function/disability assessment offers superior performance over static forms of equal length. %B Journal of Rheumatology %7 2009/09/10 %V 36 %P 2061-2066 %8 Sep %@ 0315-162X (Print)0315-162X (Linking) %G eng %M 19738214 %0 Journal Article %J Quality of Life Research %D 2009 %T Replenishing a computerized adaptive test of patient-reported daily activity functioning %A Haley, S. M. %A Ni, P. %A Jette, A. M. %A Tao, W. %A Moed, R. %A Meyers, D. %A Ludlow, L. H. %K *Activities of Daily Living %K *Disability Evaluation %K *Questionnaires %K *User-Computer Interface %K Adult %K Aged %K Cohort Studies %K Computer-Assisted Instruction %K Female %K Humans %K Male %K Middle Aged %K Outcome Assessment (Health Care)/*methods %X PURPOSE: 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. %B Quality of Life Research %7 2009/03/17 %V 18 %P 461-71 %8 May %@ 0962-9343 (Print)0962-9343 (Linking) %G eng %M 19288222 %0 Journal Article %J Archives of Physical Medicine and Rehabilitation %D 2008 %T Assessing self-care and social function using a computer adaptive testing version of the pediatric evaluation of disability inventory %A Coster, W. J. %A Haley, S. M. %A Ni, P. %A Dumas, H. M. %A Fragala-Pinkham, M. A. %K *Disability Evaluation %K *Social Adjustment %K Activities of Daily Living %K Adolescent %K Age Factors %K Child %K Child, Preschool %K Computer Simulation %K Cross-Over Studies %K Disabled Children/*rehabilitation %K Female %K Follow-Up Studies %K Humans %K Infant %K Male %K Outcome Assessment (Health Care) %K Reference Values %K Reproducibility of Results %K Retrospective Studies %K Risk Factors %K Self Care/*standards/trends %K Sex Factors %K Sickness Impact Profile %X OBJECTIVE: To examine score agreement, validity, precision, and response burden of a prototype computer adaptive testing (CAT) version of the self-care and social function scales of the Pediatric Evaluation of Disability Inventory compared with the full-length version of these scales. DESIGN: Computer simulation analysis of cross-sectional and longitudinal retrospective data; cross-sectional prospective study. SETTING: Pediatric rehabilitation hospital, including inpatient acute rehabilitation, day school program, outpatient clinics; community-based day care, preschool, and children's homes. PARTICIPANTS: Children with disabilities (n=469) and 412 children with no disabilities (analytic sample); 38 children with disabilities and 35 children without disabilities (cross-validation sample). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Summary scores from prototype CAT applications of each scale using 15-, 10-, and 5-item stopping rules; scores from the full-length self-care and social function scales; time (in seconds) to complete assessments and respondent ratings of burden. RESULTS: Scores from both computer simulations and field administration of the prototype CATs were highly consistent with scores from full-length administration (r range, .94-.99). Using computer simulation of retrospective data, discriminant validity, and sensitivity to change of the CATs closely approximated that of the full-length scales, especially when the 15- and 10-item stopping rules were applied. In the cross-validation study the time to administer both CATs was 4 minutes, compared with over 16 minutes to complete the full-length scales. CONCLUSIONS: Self-care and social function score estimates from CAT administration are highly comparable with those obtained from full-length scale administration, with small losses in validity and precision and substantial decreases in administration time. %B Archives of Physical Medicine and Rehabilitation %7 2008/04/01 %V 89 %P 622-629 %8 Apr %@ 1532-821X (Electronic)0003-9993 (Linking) %G eng %M 18373991 %2 2666276 %0 Journal Article %J Spine %D 2008 %T Computerized adaptive testing in back pain: Validation of the CAT-5D-QOL %A Kopec, J. A. %A Badii, M. %A McKenna, M. %A Lima, V. D. %A Sayre, E. C. %A Dvorak, M. %K *Disability Evaluation %K *Health Status Indicators %K *Quality of Life %K Adult %K Aged %K Algorithms %K Back Pain/*diagnosis/psychology %K British Columbia %K Diagnosis, Computer-Assisted/*standards %K Feasibility Studies %K Female %K Humans %K Internet %K Male %K Middle Aged %K Predictive Value of Tests %K Questionnaires/*standards %K Reproducibility of Results %X STUDY DESIGN: We have conducted an outcome instrument validation study. OBJECTIVE: Our objective was to develop a computerized adaptive test (CAT) to measure 5 domains of health-related quality of life (HRQL) and assess its feasibility, reliability, validity, and efficiency. SUMMARY OF BACKGROUND DATA: Kopec and colleagues have recently developed item response theory based item banks for 5 domains of HRQL relevant to back pain and suitable for CAT applications. The domains are Daily Activities (DAILY), Walking (WALK), Handling Objects (HAND), Pain or Discomfort (PAIN), and Feelings (FEEL). METHODS: An adaptive algorithm was implemented in a web-based questionnaire administration system. The questionnaire included CAT-5D-QOL (5 scales), Modified Oswestry Disability Index (MODI), Roland-Morris Disability Questionnaire (RMDQ), SF-36 Health Survey, and standard clinical and demographic information. Participants were outpatients treated for mechanical back pain at a referral center in Vancouver, Canada. RESULTS: A total of 215 patients completed the questionnaire and 84 completed a retest. On average, patients answered 5.2 items per CAT-5D-QOL scale. Reliability ranged from 0.83 (FEEL) to 0.92 (PAIN) and was 0.92 for the MODI, RMDQ, and Physical Component Summary (PCS-36). The ceiling effect was 0.5% for PAIN compared with 2% for MODI and 5% for RMQ. The CAT-5D-QOL scales correlated as anticipated with other measures of HRQL and discriminated well according to the level of satisfaction with current symptoms, duration of the last episode, sciatica, and disability compensation. The average relative discrimination index was 0.87 for PAIN, 0.67 for DAILY and 0.62 for WALK, compared with 0.89 for MODI, 0.80 for RMDQ, and 0.59 for PCS-36. CONCLUSION: The CAT-5D-QOL is feasible, reliable, valid, and efficient in patients with back pain. This methodology can be recommended for use in back pain research and should improve outcome assessment, facilitate comparisons across studies, and reduce patient burden. %B Spine %7 2008/05/23 %V 33 %P 1384-90 %8 May 20 %@ 1528-1159 (Electronic)0362-2436 (Linking) %G eng %M 18496353 %0 Journal Article %J Disability & Rehabilitation %D 2008 %T Efficiency and sensitivity of multidimensional computerized adaptive testing of pediatric physical functioning %A Allen, D. D. %A Ni, P. %A Haley, S. M. %K *Disability Evaluation %K Child %K Computers %K Disabled Children/*classification/rehabilitation %K Efficiency %K Humans %K Outcome Assessment (Health Care) %K Psychometrics %K Reproducibility of Results %K Retrospective Studies %K Self Care %K Sensitivity and Specificity %X PURPOSE: Computerized adaptive tests (CATs) have efficiency advantages over fixed-length tests of physical functioning but may lose sensitivity when administering extremely low numbers of items. Multidimensional CATs may efficiently improve sensitivity by capitalizing on correlations between functional domains. Using a series of empirical simulations, we assessed the efficiency and sensitivity of multidimensional CATs compared to a longer fixed-length test. METHOD: Parent responses to the Pediatric Evaluation of Disability Inventory before and after intervention for 239 children at a pediatric rehabilitation hospital provided the data for this retrospective study. Reliability, effect size, and standardized response mean were compared between full-length self-care and mobility subscales and simulated multidimensional CATs with stopping rules at 40, 30, 20, and 10 items. RESULTS: Reliability was lowest in the 10-item CAT condition for the self-care (r = 0.85) and mobility (r = 0.79) subscales; all other conditions had high reliabilities (r > 0.94). All multidimensional CAT conditions had equivalent levels of sensitivity compared to the full set condition for both domains. CONCLUSIONS: Multidimensional CATs efficiently retain the sensitivity of longer fixed-length measures even with 5 items per dimension (10-item CAT condition). Measuring physical functioning with multidimensional CATs could enhance sensitivity following intervention while minimizing response burden. %B Disability & Rehabilitation %7 2008/02/26 %V 30 %P 479-84 %@ 0963-8288 (Print)0963-8288 (Linking) %G eng %M 18297502 %0 Journal Article %J Spine %D 2008 %T Letting the CAT out of the bag: Comparing computer adaptive tests and an 11-item short form of the Roland-Morris Disability Questionnaire %A Cook, K. F. %A Choi, S. W. %A Crane, P. K. %A Deyo, R. A. %A Johnson, K. L. %A Amtmann, D. %K *Disability Evaluation %K *Health Status Indicators %K Adult %K Aged %K Aged, 80 and over %K Back Pain/*diagnosis/psychology %K Calibration %K Computer Simulation %K Diagnosis, Computer-Assisted/*standards %K Humans %K Middle Aged %K Models, Psychological %K Predictive Value of Tests %K Questionnaires/*standards %K Reproducibility of Results %X 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. %B Spine %7 2008/05/23 %V 33 %P 1378-83 %8 May 20 %@ 1528-1159 (Electronic) %G eng %M 18496352 %0 Journal Article %J Journal of Pediatric Orthopedics %D 2008 %T Measuring physical functioning in children with spinal impairments with computerized adaptive testing %A Mulcahey, M. J. %A Haley, S. M. %A Duffy, T. %A Pengsheng, N. %A Betz, R. R. %K *Disability Evaluation %K Adolescent %K Child %K Child, Preschool %K Computer Simulation %K Cross-Sectional Studies %K Disabled Children/*rehabilitation %K Female %K Humans %K Infant %K Kyphosis/*diagnosis/rehabilitation %K Male %K Prospective Studies %K Reproducibility of Results %K Scoliosis/*diagnosis/rehabilitation %X BACKGROUND: The purpose of this study was to assess the utility of measuring current physical functioning status of children with scoliosis and kyphosis by applying computerized adaptive testing (CAT) methods. Computerized adaptive testing uses a computer interface to administer the most optimal items based on previous responses, reducing the number of items needed to obtain a scoring estimate. METHODS: This was a prospective study of 77 subjects (0.6-19.8 years) who were seen by a spine surgeon during a routine clinic visit for progress spine deformity. Using a multidimensional version of the Pediatric Evaluation of Disability Inventory CAT program (PEDI-MCAT), we evaluated content range, accuracy and efficiency, known-group validity, concurrent validity with the Pediatric Outcomes Data Collection Instrument, and test-retest reliability in a subsample (n = 16) within a 2-week interval. RESULTS: We found the PEDI-MCAT to have sufficient item coverage in both self-care and mobility content for this sample, although most patients tended to score at the higher ends of both scales. Both the accuracy of PEDI-MCAT scores as compared with a fixed format of the PEDI (r = 0.98 for both mobility and self-care) and test-retest reliability were very high [self-care: intraclass correlation (3,1) = 0.98, mobility: intraclass correlation (3,1) = 0.99]. The PEDI-MCAT took an average of 2.9 minutes for the parents to complete. The PEDI-MCAT detected expected differences between patient groups, and scores on the PEDI-MCAT correlated in expected directions with scores from the Pediatric Outcomes Data Collection Instrument domains. CONCLUSIONS: Use of the PEDI-MCAT to assess the physical functioning status, as perceived by parents of children with complex spinal impairments, seems to be feasible and achieves accurate and efficient estimates of self-care and mobility function. Additional item development will be needed at the higher functioning end of the scale to avoid ceiling effects for older children. LEVEL OF EVIDENCE: This is a level II prospective study designed to establish the utility of computer adaptive testing as an evaluation method in a busy pediatric spine practice. %B Journal of Pediatric Orthopedics %7 2008/03/26 %V 28 %P 330-5 %8 Apr-May %@ 0271-6798 (Print)0271-6798 (Linking) %G eng %M 18362799 %2 2696932 %0 Journal Article %J Archives of Physical Medicine and Rehabilitation %D 2006 %T Measurement precision and efficiency of multidimensional computer adaptive testing of physical functioning using the pediatric evaluation of disability inventory %A Haley, S. M. %A Ni, P. %A Ludlow, L. H. %A Fragala-Pinkham, M. A. %K *Disability Evaluation %K *Pediatrics %K Adolescent %K Child %K Child, Preschool %K Computers %K Disabled Persons/*classification/rehabilitation %K Efficiency %K Humans %K Infant %K Outcome Assessment (Health Care) %K Psychometrics %K Self Care %X OBJECTIVE: To compare the measurement efficiency and precision of a multidimensional computer adaptive testing (M-CAT) application to a unidimensional CAT (U-CAT) comparison using item bank data from 2 of the functional skills scales of the Pediatric Evaluation of Disability Inventory (PEDI). DESIGN: Using existing PEDI mobility and self-care item banks, we compared the stability of item calibrations and model fit between unidimensional and multidimensional Rasch models and compared the efficiency and precision of the U-CAT- and M-CAT-simulated assessments to a random draw of items. SETTING: Pediatric rehabilitation hospital and clinics. PARTICIPANTS: Clinical and normative samples. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Not applicable. RESULTS: The M-CAT had greater levels of precision and efficiency than the separate mobility and self-care U-CAT versions when using a similar number of items for each PEDI subdomain. Equivalent estimation of mobility and self-care scores can be achieved with a 25% to 40% item reduction with the M-CAT compared with the U-CAT. CONCLUSIONS: M-CAT applications appear to have both precision and efficiency advantages compared with separate U-CAT assessments when content subdomains have a high correlation. Practitioners may also realize interpretive advantages of reporting test score information for each subdomain when separate clinical inferences are desired. %B Archives of Physical Medicine and Rehabilitation %7 2006/08/29 %V 87 %P 1223-9 %8 Sep %@ 0003-9993 (Print) %G eng %M 16935059 %0 Journal Article %J Archives of Physical Medicine and Rehabilitation %D 2005 %T Assessing mobility in children using a computer adaptive testing version of the pediatric evaluation of disability inventory %A Haley, S. M. %A Raczek, A. E. %A Coster, W. J. %A Dumas, H. M. %A Fragala-Pinkham, M. A. %K *Computer Simulation %K *Disability Evaluation %K Adolescent %K Child %K Child, Preschool %K Cross-Sectional Studies %K Disabled Children/*rehabilitation %K Female %K Humans %K Infant %K Male %K Outcome Assessment (Health Care)/*methods %K Rehabilitation Centers %K Rehabilitation/*standards %K Sensitivity and Specificity %X OBJECTIVE: To assess score agreement, validity, precision, and response burden of a prototype computerized adaptive testing (CAT) version of the Mobility Functional Skills Scale (Mob-CAT) of the Pediatric Evaluation of Disability Inventory (PEDI) as compared with the full 59-item version (Mob-59). DESIGN: Computer simulation analysis of cross-sectional and longitudinal retrospective data; and cross-sectional prospective study. SETTING: Pediatric rehabilitation hospital, including inpatient acute rehabilitation, day school program, outpatient clinics, community-based day care, preschool, and children's homes. PARTICIPANTS: Four hundred sixty-nine children with disabilities and 412 children with no disabilities (analytic sample); 41 children without disabilities and 39 with disabilities (cross-validation sample). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Summary scores from a prototype Mob-CAT application and versions using 15-, 10-, and 5-item stopping rules; scores from the Mob-59; and number of items and time (in seconds) to administer assessments. RESULTS: Mob-CAT scores from both computer simulations (intraclass correlation coefficient [ICC] range, .94-.99) and field administrations (ICC=.98) were in high agreement with scores from the Mob-59. Using computer simulations of retrospective data, discriminant validity, and sensitivity to change of the Mob-CAT closely approximated that of the Mob-59, especially when using the 15- and 10-item stopping rule versions of the Mob-CAT. The Mob-CAT used no more than 15% of the items for any single administration, and required 20% of the time needed to administer the Mob-59. CONCLUSIONS: Comparable score estimates for the PEDI mobility scale can be obtained from CAT administrations, with losses in validity and precision for shorter forms, but with a considerable reduction in administration time. %B Archives of Physical Medicine and Rehabilitation %7 2005/05/17 %V 86 %P 932-9 %8 May %@ 0003-9993 (Print) %G eng %M 15895339 %0 Journal Article %J Journal of Rehabilitation Medicine %D 2005 %T Contemporary measurement techniques for rehabilitation outcomes assessment %A Jette, A. M. %A Haley, S. M. %K *Disability Evaluation %K Activities of Daily Living/classification %K Disabled Persons/classification/*rehabilitation %K Health Status Indicators %K Humans %K Outcome Assessment (Health Care)/*methods/standards %K Recovery of Function %K Research Support, N.I.H., Extramural %K Research Support, U.S. Gov't, Non-P.H.S. %K Sensitivity and Specificity computerized adaptive testing %X In this article, we review the limitations of traditional rehabilitation functional outcome instruments currently in use within the rehabilitation field to assess Activity and Participation domains as defined by the International Classification of Function, Disability, and Health. These include a narrow scope of functional outcomes, data incompatibility across instruments, and the precision vs feasibility dilemma. Following this, we illustrate how contemporary measurement techniques, such as item response theory methods combined with computer adaptive testing methodology, can be applied in rehabilitation to design functional outcome instruments that are comprehensive in scope, accurate, allow for compatibility across instruments, and are sensitive to clinically important change without sacrificing their feasibility. Finally, we present some of the pressing challenges that need to be overcome to provide effective dissemination and training assistance to ensure that current and future generations of rehabilitation professionals are familiar with and skilled in the application of contemporary outcomes measurement. %B Journal of Rehabilitation Medicine %V 37 %P 339-345 %G eng %M 16287664 %0 Generic %D 2004 %T The AMC Linear Disability Score project in a population requiring residential care: psychometric properties %A Holman, R. %A Lindeboom, R. %A Vermeulen, M. %A de Haan, R. J. %K *Disability Evaluation %K *Health Status Indicators %K Activities of Daily Living/*classification %K Adult %K Aged %K Aged, 80 and over %K Data Collection/methods %K Female %K Humans %K Logistic Models %K Male %K Middle Aged %K Netherlands %K Pilot Projects %K Probability %K Psychometrics/*instrumentation %K Questionnaires/standards %K Residential Facilities/*utilization %K Severity of Illness Index %X BACKGROUND: Currently there is a lot of interest in the flexible framework offered by item banks for measuring patient relevant outcomes, including functional status. However, there are few item banks, which have been developed to quantify functional status, as expressed by the ability to perform activities of daily life. METHOD: This paper examines the psychometric properties of the AMC Linear Disability Score (ALDS) project item bank using an item response theory model and full information factor analysis. Data were collected from 555 respondents on a total of 160 items. RESULTS: Following the analysis, 79 items remained in the item bank. The remaining 81 items were excluded because of: difficulties in presentation (1 item); low levels of variation in response pattern (28 items); significant differences in measurement characteristics for males and females or for respondents under or over 85 years old (26 items); or lack of model fit to the data at item level (26 items). CONCLUSIONS: It is conceivable that the item bank will have different measurement characteristics for other patient or demographic populations. However, these results indicate that the ALDS item bank has sound psychometric properties for respondents in residential care settings and could form a stable base for measuring functional status in a range of situations, including the implementation of computerised adaptive testing of functional status. %B Health and Quality of Life Outcomes %7 2004/08/05 %V 2 %P 42 %8 Aug 3 %@ 1477-7525 (Electronic)1477-7525 (Linking) %G eng %M 15291958 %2 514531 %0 Generic %D 2004 %T Practical methods for dealing with 'not applicable' item responses in the AMC Linear Disability Score project %A Holman, R. %A Glas, C. A. %A Lindeboom, R. %A Zwinderman, A. H. %A de Haan, R. J. %K *Disability Evaluation %K *Health Surveys %K *Logistic Models %K *Questionnaires %K Activities of Daily Living/*classification %K Data Interpretation, Statistical %K Health Status %K Humans %K Pilot Projects %K Probability %K Quality of Life %K Severity of Illness Index %X BACKGROUND: Whenever questionnaires are used to collect data on constructs, such as functional status or health related quality of life, it is unlikely that all respondents will respond to all items. This paper examines ways of dealing with responses in a 'not applicable' category to items included in the AMC Linear Disability Score (ALDS) project item bank. METHODS: The data examined in this paper come from the responses of 392 respondents to 32 items and form part of the calibration sample for the ALDS item bank. The data are analysed using the one-parameter logistic item response theory model. The four practical strategies for dealing with this type of response are: cold deck imputation; hot deck imputation; treating the missing responses as if these items had never been offered to those individual patients; and using a model which takes account of the 'tendency to respond to items'. RESULTS: The item and respondent population parameter estimates were very similar for the strategies involving hot deck imputation; treating the missing responses as if these items had never been offered to those individual patients; and using a model which takes account of the 'tendency to respond to items'. The estimates obtained using the cold deck imputation method were substantially different. CONCLUSIONS: The cold deck imputation method was not considered suitable for use in the ALDS item bank. The other three methods described can be usefully implemented in the ALDS item bank, depending on the purpose of the data analysis to be carried out. These three methods may be useful for other data sets examining similar constructs, when item response theory based methods are used. %B Health and Quality of Life Outcomes %7 2004/06/18 %V 2 %P 29 %8 Jun 16 %@ 1477-7525 (Electronic)1477-7525 (Linking) %G eng %9 Comparative StudyResearch Support, Non-U.S. Gov't %M 15200681 %2 441407