%0 Journal Article %J Medical Care %D 2004 %T Activity outcome measurement for postacute care %A Haley, S. M. %A Coster, W. J. %A Andres, P. L. %A Ludlow, L. H. %A Ni, P. %A Bond, T. L. %A Sinclair, S. J. %A Jette, A. M. %K *Self Efficacy %K *Sickness Impact Profile %K Activities of Daily Living/*classification/psychology %K Adult %K Aftercare/*standards/statistics & numerical data %K Aged %K Boston %K Cognition/physiology %K Disability Evaluation %K Factor Analysis, Statistical %K Female %K Human %K Male %K Middle Aged %K Movement/physiology %K Outcome Assessment (Health Care)/*methods/statistics & numerical data %K Psychometrics %K Questionnaires/standards %K Rehabilitation/*standards/statistics & numerical data %K Reproducibility of Results %K Sensitivity and Specificity %K Support, U.S. Gov't, Non-P.H.S. %K Support, U.S. Gov't, P.H.S. %X BACKGROUND: Efforts to evaluate the effectiveness of a broad range of postacute care services have been hindered by the lack of conceptually sound and comprehensive measures of outcomes. It is critical to determine a common underlying structure before employing current methods of item equating across outcome instruments for future item banking and computer-adaptive testing applications. OBJECTIVE: To investigate the factor structure, reliability, and scale properties of items underlying the Activity domains of the International Classification of Functioning, Disability and Health (ICF) for use in postacute care outcome measurement. METHODS: We developed a 41-item Activity Measure for Postacute Care (AM-PAC) that assessed an individual's execution of discrete daily tasks in his or her own environment across major content domains as defined by the ICF. We evaluated the reliability and discriminant validity of the prototype AM-PAC in 477 individuals in active rehabilitation programs across 4 rehabilitation settings using factor analyses, tests of item scaling, internal consistency reliability analyses, Rasch item response theory modeling, residual component analysis, and modified parallel analysis. RESULTS: Results from an initial exploratory factor analysis produced 3 distinct, interpretable factors that accounted for 72% of the variance: Applied Cognition (44%), Personal Care & Instrumental Activities (19%), and Physical & Movement Activities (9%); these 3 activity factors were verified by a confirmatory factor analysis. Scaling assumptions were met for each factor in the total sample and across diagnostic groups. Internal consistency reliability was high for the total sample (Cronbach alpha = 0.92 to 0.94), and for specific diagnostic groups (Cronbach alpha = 0.90 to 0.95). Rasch scaling, residual factor, differential item functioning, and modified parallel analyses supported the unidimensionality and goodness of fit of each unique activity domain. CONCLUSIONS: This 3-factor model of the AM-PAC can form the conceptual basis for common-item equating and computer-adaptive applications, leading to a comprehensive system of outcome instruments for postacute care settings. %B Medical Care %V 42 %P I49-161 %G eng %M 14707755 %0 Journal Article %J Medical Care %D 2004 %T Refining the conceptual basis for rehabilitation outcome measurement: personal care and instrumental activities domain %A Coster, W. J. %A Haley, S. M. %A Andres, P. L. %A Ludlow, L. H. %A Bond, T. L. %A Ni, P. S. %K *Self Efficacy %K *Sickness Impact Profile %K Activities of Daily Living/*classification/psychology %K Adult %K Aged %K Aged, 80 and over %K Disability Evaluation %K Factor Analysis, Statistical %K Female %K Humans %K Male %K Middle Aged %K Outcome Assessment (Health Care)/*methods/statistics & numerical data %K Questionnaires/*standards %K Recovery of Function/physiology %K Rehabilitation/*standards/statistics & numerical data %K Reproducibility of Results %K Research Support, U.S. Gov't, Non-P.H.S. %K Research Support, U.S. Gov't, P.H.S. %K Sensitivity and Specificity %X BACKGROUND: Rehabilitation outcome measures routinely include content on performance of daily activities; however, the conceptual basis for item selection is rarely specified. These instruments differ significantly in format, number, and specificity of daily activity items and in the measurement dimensions and type of scale used to specify levels of performance. We propose that a requirement for upper limb and hand skills underlies many activities of daily living (ADL) and instrumental activities of daily living (IADL) items in current instruments, and that items selected based on this definition can be placed along a single functional continuum. OBJECTIVE: To examine the dimensional structure and content coverage of a Personal Care and Instrumental Activities item set and to examine the comparability of items from existing instruments and a set of new items as measures of this domain. METHODS: Participants (N = 477) from 3 different disability groups and 4 settings representing the continuum of postacute rehabilitation care were administered the newly developed Activity Measure for Post-Acute Care (AM-PAC), the SF-8, and an additional setting-specific measure: FIM (in-patient rehabilitation); MDS (skilled nursing facility); MDS-PAC (postacute settings); OASIS (home care); or PF-10 (outpatient clinic). Rasch (partial-credit model) analyses were conducted on a set of 62 items covering the Personal Care and Instrumental domain to examine item fit, item functioning, and category difficulty estimates and unidimensionality. RESULTS: After removing 6 misfitting items, the remaining 56 items fit acceptably along the hypothesized continuum. Analyses yielded different difficulty estimates for the maximum score (eg, "Independent performance") for items with comparable content from different instruments. Items showed little differential item functioning across age, diagnosis, or severity groups, and 92% of the participants fit the model. CONCLUSIONS: ADL and IADL items from existing rehabilitation outcomes instruments that depend on skilled upper limb and hand use can be located along a single continuum, along with the new personal care and instrumental items of the AM-PAC addressing gaps in content. Results support the validity of the proposed definition of the Personal Care and Instrumental Activities dimension of function as a guide for future development of rehabilitation outcome instruments, such as linked, setting-specific short forms and computerized adaptive testing approaches. %B Medical Care %V 42 %P I62-172 %8 Jan %G eng %M 14707756