Pengsheng Ni

Prospective Evaluation of the AM-PAC-CAT in Outpatient Rehabilitation Settings

Background and Purpose The purpose of this study was to prospectively evaluate the practical and psychometric adequacy of the Activity Measure for Post-Acute Care (AM-PAC) “item bank” and computerized adaptive testing (CAT) assessment platform (AM-PAC-CAT) when applied within orthopedic outpatient physical therapy settings. Method This was a prospective study with a convenience sample of 1,815 patients with spine, lower-extremity, or upper-extremity impairments who received outpatient physical therapy in 1 of 20 outpatient clinics across 5 states. The authors conducted an evaluation of the number of items used and amount of time needed to complete the CAT assessment; evaluation of breadth of content coverage, item exposure rate, and test precision; as well as an assessment of the validity and sensitivity to change of the score estimates. Results Overall, the AM-PAC-CATs Basic Mobility scale demonstrated excellent psychometric properties while the Daily Activity scale demonstrated less adequate psychometric properties when applied in this outpatient sample. The mean length of time to complete the Basic Mobility scale was 1.9 minutes, using, on average, 6.6 items per CAT session, and the mean length of time to complete the Daily Activity scale was 1.01 minutes, using on average, 6.8 items. Background and Conclusion Overall, the findings are encouraging, yet they do reveal several areas where the AM-PAC-CAT scales can be improved to best suit the needs of patients who are receiving outpatient orthopedic physical therapy of the type included in this study.

Clinical Meaningfulness of the Changes in Muscle Performance and Physical Function Associated With Testosterone Administration in Older Men With Mobility Limitation

CONTEXT Testosterone in Older Men with Mobility Limitations Trial determined the effects of testosterone on muscle performance and physical function in older men with mobility limitation. Trials Data and Safety Monitoring Board recommended enrollment cessation due to increased frequency of adverse events in testosterone arm. The changes in muscle performance and physical function were evaluated in relation to participants perception of change. METHODS Men aged 65 years and older, with mobility limitation, total testosterone 100-350 ng/dL, or free testosterone less than 50 pg/mL, were randomized to placebo or 10 g testosterone gel daily for 6 months. Primary outcome was leg-press strength. Secondary outcomes included chest-press strength, stair-climb, 40-m walk, muscle mass, physical activity, self-reported function, and fatigue. Proportions of participants exceeding minimally important difference in study arms were compared. RESULTS Of 209 randomized participants, 165 had follow-up efficacy measures. Mean (SD) age was 74 (5.4) years and short physical performance battery score 7.7 (1.4). Testosterone arm exhibited greater improvements in leg-press strength, chest-press strength and power, and loaded stair-climb than placebo. Compared with placebo, significantly greater proportion of men receiving testosterone improved their leg-press and chest-press strengths (43% vs 18%, p = .01) and stair-climbing power (28% vs 10%, p = .03) more than minimally important difference. Increases in leg-press strength and stair-climbing power were associated with changes in testosterone levels and muscle mass. Physical activity, walking speed, self-reported function, and fatigue did not change. CONCLUSIONS Testosterone administration in older men with mobility limitation was associated with patient-important improvements in muscle strength and stair-climbing power. Improvements in muscle strength and only some physical function measures should be weighed against the risk of adverse events in this population.

Sensitivity to Change and Responsiveness of Four Balance Measures for Community-Dwelling Older Adults

Background Impaired balance has a significant negative impact on mobility, functional independence, and fall risk in older adults. Although several, well-respected balance measures are currently in use, there is limited evidence regarding the most appropriate measure to assess change in community-dwelling older adults. Objective The aim of this study was to compare floor and ceiling effects, sensitivity to change, and responsiveness across the following balance measures in community-dwelling elderly people with functional limitations: Berg Balance Scale (BBS), Performance-Oriented Mobility Assessment total scale (POMA-T), POMA balance subscale (POMA-B), and Dynamic Gait Index (DGI). Design Retrospective data from a 16-week exercise trial were used. Secondary analyses were conducted on the total sample and by subgroups of baseline functional limitation or baseline balance scores. Methods Participants were 111 community-dwelling older adults 65 years of age or older, with functional limitations. Sensitivity to change was assessed using effect size, standardized response mean, and paired t tests. Responsiveness was assessed using minimally important difference (MID) estimates. Results No floor effects were noted. Ceiling effects were observed on all measures, including in people with moderate to severe functional limitations. The POMA-T, POMA-B, and DGI showed significantly larger ceiling effects compared with the BBS. All measures had low sensitivity to change in total sample analyses. Subgroup analyses revealed significantly better sensitivity to change in people with lower compared with higher baseline balance scores. Although both the total sample and lower baseline balance subgroups showed statistically significant improvement from baseline to 16 weeks on all measures, only the lower balance subgroup showed change scores that consistently exceeded corresponding MID estimates. Limitations This study was limited to comparing 4 measures of balance, and anchor-based methods for assessing MID could not be reported. Conclusions Important limitations, including ceiling effects and relatively low sensitivity to change and responsiveness, were noted across all balance measures, highlighting their limited utility across the full spectrum of the community-dwelling elderly population. New, more challenging measures are needed for better discrimination of balance ability in community-dwelling elderly people at higher functional levels.

Refining the Conceptual Basis for Rehabilitation Outcome Measurement: Personal Care and Instrumental Activities Domain

BackgroundRehabilitation 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. ObjectiveTo 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. MethodsParticipants (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. ResultsAfter 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. ConclusionsADL 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.

Accuracy and Precision of the Pediatric Evaluation of Disability Inventory Computer-Adaptive Tests (PEDI-CAT)

Aim  The aims of the study were to: (1) build new item banks for a revised version of the Pediatric Evaluation of Disability Inventory (PEDI) with four content domains: daily activities, mobility, social/cognitive, and responsibility; and (2) use post‐hoc simulations based on the combined normative and disability calibration samples to assess the accuracy and precision of the PEDI computer‐adaptive tests (PEDI‐CAT) compared with the administration of all items.

Function and disability in late life: comparison of the Late-Life Function and Disability Instrument to the Short-Form-36 and the London Handicap Scale

Purpose: We evaluated the Late-Life Function and Disability Instruments (LLFDI) concurrent validity, comprehensiveness and precision by comparing it with the Short-Form-36 physical functioning (PF-10) and the London Handicap Scale (LHS). Methods: We administered the LLFDI, PF-10 and LHS to 75 community-dwelling adults (> 60 years of age). We used Pearson correlation coefficients to examine concurrent validity and Rasch analysis to compare the item hierarchies, content ranges and precision of the PF-10 and LLFDI function domains, and the LHS and the LLFDI disability domains. Results: LLFDI Function (lower extremity scales) and PF-10 scores were highly correlated (r = 0.74 − 0.86, p > 0.001); moderate correlations were found between the LHS and the LLFDI Disability limitation (r = 0.66, p < 0.0001) and Disability frequency (r = 0.47, p < 0.001) scores. The LLFDI had a wider range of content coverage, less ceiling effects and better relative precision across the spectrum of function and disability than the PF-10 and the LHS. The LHS had slightly more content range and precision in the lower end of the disability scale than the LLFDI. Conclusions: The LLFDI is a more comprehensive and precise instrument compared to the PF-10 and LHS for assessing function and disability in community-dwelling older adults.

Computer adaptive test performance in children with and without disabilities: prospective field study of the PEDI-CAT.

Purpose: To examine the discriminant validity, test–retest reliability, administration time and acceptability of the pediatric evaluation of disability inventory computer adaptive test (PEDI-CAT). Methods: A sample of 102 parents of children 3 through 20 years of age with (n = 50) and without (n = 52) disabilities was recruited for this prospective field study. A sub-sample (n = 25) also completed the PEDI-CAT a second time within one month. Parents completed 15 items in each of the four PEDI-CAT domains (daily activities, mobility, social/cognitive, responsibility) using a laptop computer. Following completion, parents answered a four-question user evaluation survey. Results: PEDI-CAT scores based on parent responses differentiated between groups of children with and without disabilities in all four domains. Test–retest reliability estimates were high (ICC = 0.96–0.99) for all four domains. The mean time to complete 60 items for the full sample (n = 102) was 12.66 minutes (SD = 4.47). Parents reported favorable reactions to the PEDI-CAT. Conclusions: The PEDI-CAT offers a valid and reliable assessment acceptable to parents. Implications for rehabilitation The pediatric evaluation of disability inventory computer adaptive test (PEDI-CAT) is a new measure for infants, children and youth from birth through 20 years of age in the functional areas of daily activities, mobility, social/cognitive and responsibility. PEDI-CAT scores based on parent responses differentiated functional skills between groups of children with and without disabilities in all four domains. The PEDI-CAT has high test–retest reliability and could be completed in about 12 minutes. Parent respondents indicated they provided meaningful information about their child with the PEDI-CAT.

Sensitivity of a computer adaptive assessment for measuring functional mobility changes in children enrolled in a community fitness programme

Objective: To examine the relative sensitivity to detect functional mobility changes with a full-length parent questionnaire compared with a computerized adaptive testing version of the questionnaire after a 16-week group fitness programme. Design: Prospective, pre- and posttest study with a 16-week group fitness intervention. Setting: Three community-based fitness centres. Subjects: Convenience sample of children (n = 28) with physical or developmental disabilities. Interventions: A 16-week group exercise programme held twice a week in a community setting. Main measures: A full-length (161 items) paper version of a mobility parent questionnaire based on the Pediatric Evaluation of Disability Inventory, but expanded to include expected skills of children up to 15 years old was compared with a 15-item computer adaptive testing version. Both measures were administered at pre- and posttest intervals. Results: Both the full-length Pediatric Evaluation of Disability Inventory and the 15- item computer adaptive testing version detected significant changes between pre and posttest scores, had large effect sizes, and standardized response means, with a modest decrease in the computer adaptive test as compared with the 161-item paper version. Correlations between the computer adaptive and paper formats across pre and posttest scores ranged from r = 0.76 to 0.86. Conclusions: Both functional mobility test versions were able to detect positive functional changes at the end of the intervention period. Greater variability in score estimates was generated by the computerized adaptive testing version, which led to a relative reduction in sensitivity as defined by the standardized response mean. Extreme scores were generally more difficult for the computer adaptive format to estimate with as much accuracy as scores in the mid-range of the scale. However, the reduction in accuracy and sensitivity, which did not influence the group effect results in this study, is counterbalanced by the large reduction in testing burden.

Evaluation of an Item Bank for a Computerized Adaptive Test of Activity in Children With Cerebral Palsy

Background: Contemporary clinical assessments of activity are needed across the age span for children with cerebral palsy (CP). Computerized adaptive testing (CAT) has the potential to efficiently administer items for children across wide age spans and functional levels. Objective: The objective of this study was to examine the psychometric properties of a new item bank and simulated computerized adaptive test to assess activity level abilities in children with CP. Design: This was a cross-sectional item calibration study. Methods: The convenience sample consisted of 308 children and youth with CP, aged 2 to 20 years (X=10.7, SD=4.0), recruited from 4 pediatric hospitals. We collected parent-report data on an initial set of 45 activity items. Using an Item Response Theory (IRT) approach, we compared estimated scores from the activity item bank with concurrent instruments, examined discriminate validity, and developed computer simulations of a CAT algorithm with multiple stop rules to evaluate scale coverage, score agreement with CAT algorithms, and discriminant and concurrent validity. Results: Confirmatory factor analysis supported scale unidimensionality, local item dependence, and invariance. Scores from the computer simulations of the prototype CATs with varying stop rules were consistent with scores from the full item bank (r=.93–.98). The activity summary scores discriminated across levels of upper-extremity and gross motor severity and were correlated with the Pediatric Outcomes Data Collection Instrument (PODCI) physical function and sports subscale (r=.86), the Functional Independence Measure for Children (Wee-FIM) (r=.79), and the Pediatric Quality of Life Inventory–Cerebral Palsy version (r=.74). Limitations: The sample size was small for such IRT item banks and CAT development studies. Another limitation was oversampling of children with CP at higher functioning levels. Conclusions: The new activity item bank appears to have promise for use in a CAT application for the assessment of activity abilities in children with CP across a wide age range and different levels of motor severity.

Spinal cord injury-functional index: item banks to measure physical functioning in individuals with spinal cord injury.

OBJECTIVES To develop a comprehensive set of patient-reported items to assess multiple aspects of physical functioning relevant to the lives of people with spinal cord injury (SCI), and to evaluate the underlying structure of physical functioning. DESIGN Cross-sectional. SETTING Inpatient and community. PARTICIPANTS Item pools of physical functioning were developed, refined, and field tested in a large sample of individuals (N=855) with traumatic SCI stratified by diagnosis, severity, and time since injury. INTERVENTIONS None. MAIN OUTCOME MEASURE Spinal Cord Injury-Functional Index (SCI-FI) measurement system. RESULTS Confirmatory factor analysis (CFA) indicated that a 5-factor model, including basic mobility, ambulation, wheelchair mobility, self-care, and fine motor function, had the best model fit and was most closely aligned conceptually with feedback received from individuals with SCI and SCI clinicians. When just the items making up basic mobility were tested in CFA, the fit statistics indicated strong support for a unidimensional model. Similar results were demonstrated for each of the other 4 factors, indicating unidimensional models. CONCLUSIONS Though unidimensional or 2-factor (mobility and upper extremity) models of physical functioning make up outcomes measures in the general population, the underlying structure of physical function in SCI is more complex. A 5-factor solution allows for comprehensive assessment of key domain areas of physical functioning. These results informed the structure and development of the SCI-FI measurement system of physical functioning.