Deductive automated pollen classification in environmental samples via exploratory deep learning and imaging flow cytometry.

Pollen and tracheophyte spores are ubiquitous environmental indicators at local and global scales. Palynology is typically performed manually by microscopic analysis; a specialised and time-consuming task limited in taxonomical precision and sampling frequency, therefore restricting data quality used to inform climate change and pollen forecasting models. We build on the growing work using AI (artificial intelligence) for automated pollen classification to design a flexible network that can deal with the uncertainty of broad-scale environmental applications. We combined imaging flow cytometry with Guided Deep Learning to identify and accurately categorise pollen in environmental samples; here, pollen grains captured within c. 5500 Cal yr BP old lake sediments. Our network discriminates not only pollen included in training libraries to the species level but, depending on the sample, can classify previously unseen pollen to the likely phylogenetic order, family and even genus. Our approach offers valuable insights into the development of a widely transferable, rapid and accurate exploratory tool for pollen classification in 'real-world' environmental samples with improved accuracy over pure deep learning techniques. This work has the potential to revolutionise many aspects of palynology, allowing a more detailed spatial and temporal understanding of pollen in the environment with improved taxonomical resolution.

Minimal Information about MHC Multimers (MIAMM).

With the goal of improving the reproducibility and annotatability of MHC multimer reagent data, we present the establishment of a new data standard: Minimal Information about MHC Multimers (https://miamm.lji.org/). Multimers are engineered reagents composed of a ligand and a MHC, which can be represented in a standardized format using ontology terminology. We provide an online Web site to host the details of the standard, as well as a validation tool to assist with the adoption of the standard. We hope that this publication will bring increased awareness of Minimal Information about MHC Multimers and drive acceptance, ultimately improving the quality and documentation of multimer data in the scientific literature.

A prototype tracing-technique to assess the mobility of dispersed earthworm casts on a vegetated hillslope using caesium-134 and cobalt-60.

Soil transport on fully vegetated land surfaces is typically detachment limited. Rates of soil and nutrient transport, and ultimately long-term landscape evolution, are controlled by processes that supply soil material for entrainment and transport. Despite their on-going nature, many such processes operate at low rates and have not been subject to detailed investigation. We present preliminary findings from a prototype tracing approach to quantify one such process; namely to determine the relative mobility of sediment from earthworm casts on a fully vegetated hillslope surface. A 0.6 ∗ 0.5 m bounded area of pasture was prepared and fifteen intact earthworm casts representing 203 g of soil were labelled with an estimated 216 Bq of caesium-134 (134Cs) activity and evenly distributed across the upslope half of the plot, 0.3-0.6 m from the downslope outlet. A further 15 intact casts representing 190.7 g of soil were labelled with 224 Bq of cobalt-60 (60Co) activity and distributed between 0.3 and 0.0 m from the same outlet. All labelled casts were exposed to natural weather events over 76 days, during which time 186.3 mm of rainfall generated 16 runoff samples. A mass balance was used to partition labelled sediment from the unlabelled material. A total of 27.17 g of 60Co-labelled casts, equivalent to 14.2% of the original mass deployed, was recovered from a distance of ≤0.3 m from their original locations. In contrast, 8.77 g of 134Cs-labelled casts, equivalent to 4.3% of the original mass deployed, was recovered from a distance ≥0.3 m from their original locations. Some runoff-derived samples recorded an over-enrichment of radionuclide material, which suggests that intact casts may sorb more material than the original assumption predicts. Ways in which sorption can be more accurately quantified to improve the accuracy of the tracing approach are outlined.

Development and Validation of a Computerized-Adaptive Test for PTSD (P-CAT).

OBJECTIVE: The primary purpose was to develop, field test, and validate a computerized-adaptive test (CAT) for posttraumatic stress disorder (PTSD) to enhance PTSD assessment and decrease the burden of symptom monitoring. METHODS: Data sources included self-report and interviewer-administered diagnostic interviews. The sample included 1,288 veterans. In phase 1, 89 items from a previously developed PTSD item pool were administered to a national sample of 1,085 veterans. A multidimensional graded-response item response theory model was used to calibrate items for incorporation into a CAT for PTSD (P-CAT). In phase 2, in a separate sample of 203 veterans, the P-CAT was validated against three other self-report measures (PTSD Checklist, Civilian Version; Mississippi Scale for Combat-Related PTSD; and Primary Care PTSD Screen) and the PTSD module of the Structured Clinical Interview for DSM-IV. RESULTS: A bifactor model with one general PTSD factor and four subfactors consistent with DSM-5 (reexperiencing, avoidance, negative mood-cognitions, and arousal), yielded good fit. The P-CAT discriminated veterans with PTSD from those with other mental health conditions and those with no mental health conditions (Cohen's d effect sizes >.90). The P-CAT also discriminated those with and without a PTSD diagnosis and those who screened positive versus negative for PTSD. Concurrent validity was supported by high correlations (r=.85-.89) with the validation measures. CONCLUSIONS: The P-CAT appears to be a promising tool for efficient and accurate assessment of PTSD symptomatology. Further testing is needed to evaluate its responsiveness to change. With increasing availability of computers and other technologies, CAT may be a viable and efficient assessment method.

Linkage between the PROMIS® pediatric and adult emotional distress measures.

PURPOSE: Research studies that measure health-related quality of life (HRQOL) in both children and adults and longitudinal studies that follow children into adulthood need measures that can be compared across these age groups. This study links the PROMIS pediatric and adult emotional distress measures using data from participants with diverse health conditions and disabilities. METHODS: Analyses were conducted and compared in two separate samples to confirm the stability of results. One sample (n = 874) included individuals aged 14-20 years with special health care needs and who require health services. The other sample (n = 641) included individuals aged 14-25 years who have a physical or cognitive disability. Participants completed both PROMIS pediatric and adult measures. Item response theory-based scores were linked using the linear approximation to calibrated projection. RESULTS: The estimated latent-variable correlation between pediatric and adult PROMIS measures ranged from 0.87 to 0.94. Regression coefficients ß 0 (intercept) and ß 1 (slope), and mean squared error are provided to transform scores from the pediatric to the adult measures, and vice versa. CONCLUSIONS: This study used a relatively new linking method, calibrated projection, to link PROMIS pediatric and adult measure scores, thus expanding the use of PROMIS measures to research that includes both populations.

Development of an IRT-Based Short Form to Assess Applied Cognitive Function in Outpatient Rehabilitation.

OBJECTIVE: Item response theory and computerized adaptive testing methods allow the development of a large calibrated item bank from which different subsets of questions can be selected for administration and scored on a common scale. The objective of this study was to develop an outpatient rehabilitation self-report short form for the Activity Measure for Post-Acute Care Applied Cognition item bank. DESIGN: Using data from a convenience sample of 235 rehabilitation outpatients, item content and item response theory-based test information function parameters were used in item selection. Internal consistency reliability, intraclass correlation coefficient (ICC), and percentage at the lowest (floor) and highest (ceiling) scores were evaluated for the short form and full item bank. RESULTS: A 15-item short form was developed. The internal consistency of the short form was 0.86. The ICC3,1 for the short form and item bank was 0.97 (95% confidence interval, 0.94-0.98). No floor effects were noted, and ceiling effects were 27.66% (short form) and 26.38% (full item bank). CONCLUSIONS: The Applied Cognition outpatient short form demonstrated acceptable psychometric properties and provides a bridge to item response theory-based measurement for settings where point-of-care computing is not available.

Ability of PROMIS Pediatric Measures to Detect Change in Children With Cerebral Palsy Undergoing Musculoskeletal Surgery.

BACKGROUND: The Patient Reported Outcomes Measurement Information System (PROMIS) was developed to provide patient-reported outcome measures that are designed as being universally relevant across health conditions, low burden, and precise. A major problem for research and clinical practice in cerebral palsy (CP) is the void of outcomes instruments that are capable of evaluating the wide range of abilities and broad age spectrum inherent in this clinical population. Given the tremendous potential of PROMIS, the research questions for this study were "How do PROMIS pediatric computer adaptive tests and short forms detect change in children with CP following elective musculoskeletal surgery?" and "How do PROMIS instruments compare to the Pediatric Quality of Life Inventory Cerebral Palsy Module Version 3.0 (PedsQL CP), Pediatric Outcomes Data Collection Instrument (PODCI), the Timed Up and Go (TUG), and the Gross Motor Functional Measure (GMFM)." METHODS: PROMIS Pediatric computer adaptive tests and short forms and the PedsQL, PODCI, TUG, and GMFM were administered before and after surgery. Effect size (ES) and standardized response mean (SRM) were calculated. Floor and ceiling effects were evaluated and, exposure rates for the PROMIS item banks were examined. RESULTS: ES and SRM for all PROMIS Pediatric Measures were nonsignificant. PedsQL CP detected significant, positive change in mobility at 6 (ES=0.26; SRM=0.31) and 12 (ES=0.36; SRM=0.36) months; pain at 12 months (ES=0.29; SRM=0.34); and fatigue at 6 (ES=0.24; SRM=0.22) and 12 (ES=0.36; SRM=0.41) months. Significant negative changes were detected by the PODCI (ES=-0.20; SRM=-0.26), GMFM (ES=-0.13; SRM=-0.24), and TUG (ES=-0.29; SRM=-0.25). Ceiling effects were high. Exposure to an appropriate range of the PROMIS Mobility item bank was limited. CONCLUSIONS: PROMIS measures were less able to detect change than other measures. PROMIS measures may be improved by tailoring start/stop rules or by adding items to include content appropriate for children with mobility impairments. LEVEL OF EVIDENCE: Level III-diagnostic study.

Computerized Adaptive Tests Detect Change Following Orthopaedic Surgery in Youth with Cerebral Palsy.

BACKGROUND: The Cerebral Palsy Computerized Adaptive Test (CP-CAT) is a parent-reported outcomes instrument for measuring lower and upper-extremity function, activity, and global health across impairment levels and a broad age range of children with cerebral palsy (CP). This study was performed to examine whether the Lower Extremity/Mobility (LE) CP-CAT detects change in mobility following orthopaedic surgery in children with CP. METHODS: This multicenter, longitudinal study involved administration of the LE CP-CAT, the Pediatric Outcomes Data Collection Instrument (PODCI) Transfer/Mobility and Sports/Physical Functioning domains, and the Timed "Up & Go" test (TUG) before and after elective orthopaedic surgery in a convenience sample of 255 children, four to twenty years of age, who had CP and a Gross Motor Function Classification System (GMFCS) level of I, II, or III. Standardized response means (SRMs) and 95% confidence intervals (CIs) were calculated for all measures at six, twelve, and twenty-four months following surgery. RESULTS: SRM estimates for the LE CP-CAT were significantly greater than the SRM estimates for the PODCI Transfer/Mobility domain at twelve months, the PODCI Sports/Physical Functioning domain at twelve months, and the TUG at twelve and twenty-four months. When the results for the children at GMFCS levels I, II, and III were grouped together, the improvements in function detected by the LE CP-CAT at twelve and twenty-four months were found to be greater than the changes detected by the PODCI Transfer/Mobility and Sports/Physical Functioning scales. The LE CP-CAT outperformed the PODCI scales for GMFCS levels I and III at both of these follow-up intervals; none of the scales performed well for patients with GMFCS level II. CONCLUSIONS: The results of this study showed that the LE CP-CAT displayed superior sensitivity to change than the PODCI and TUG scales after musculoskeletal surgery in children with CP.

Stereoretentive Pd-catalyzed Kumada-Corriu couplings of alkenyl halides at room temperature.

Stereoselective palladium-catalyzed Kumada-Corriu reactions of functionalized alkenyl halides and a variety of Grignard reagents, including those bearing ß-hydrogen atoms and sensitive functional groups, can be carried out at room temperature using a new combination of reagents.

Tracking functional status across the spinal cord injury lifespan: linking pediatric and adult patient-reported outcome scores.

OBJECTIVE: To use item response theory (IRT) methods to link scores from 2 recently developed contemporary functional outcome measures, the adult Spinal Cord Injury-Functional Index (SCI-FI) and the Pedi SCI (both the parent version and the child version). DESIGN: Secondary data analysis of the physical functioning items of the adult SCI-FI and the Pedi SCI instruments. We used a nonequivalent group design with items common to both instruments and the Stocking-Lord method for the linking. Linking was conducted so that the adult SCI-FI and Pedi SCI scaled scores could be compared. SETTING: Community. PARTICIPANTS: This study included a total sample of 1558 participants. Pedi SCI items were administered to a sample of children (n=381) with SCI aged 8 to 21 years, and of parents/caregivers (n=322) of children with SCI aged 4 to 21 years. Adult SCI-FI items were administered to a sample of adults (n=855) with SCI aged 18 to 92 years. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Five scales common to both instruments were included in the analysis: Wheelchair, Daily Routine/Self-care, Daily Routine/Fine Motor, Ambulation, and General Mobility functioning. RESULTS: Confirmatory factor analysis and exploratory factor analysis results indicated that the 5 scales are unidimensional. A graded response model was used to calibrate the items. Misfitting items were identified and removed from the item banks. Items that function differently between the adult and child samples (ie, exhibit differential item functioning) were identified and removed from the common items used for linking. Domain scores from the Pedi SCI instruments were transformed onto the adult SCI-FI metric. CONCLUSIONS: This IRT linking allowed estimation of adult SCI-FI scale scores based on Pedi SCI scale scores and vice versa; therefore, it provides clinicians with a means of tracking long-term functional data for children with an SCI across their entire lifespan.

Confocal microscopy of cardiac myocytes.

Detailed methods are provided for the preparation and confocal imaging of cardiac myocyte development and differentiation. Examples include protocols for the analysis of cultured myocytes as well as vibratome sections of hearts from embryonic and adult tissue. Techniques include routine labeling of F-actin with phalloidin as well as multiple labeling protocols for colocalization studies and cell volume analysis.

Validity of computer adaptive tests of daily routines for youth with spinal cord injury.

OBJECTIVE: To evaluate the accuracy of computer adaptive tests (CATs) of daily routines for child- and parent-reported outcomes following pediatric spinal cord injury (SCI) and to evaluate the validity of the scales. METHODS: One hundred ninety-six daily routine items were administered to 381 youths and 322 parents. Pearson correlations, intraclass correlation coefficients (ICC), and 95% confidence intervals (CI) were calculated to evaluate the accuracy of simulated 5-item, 10-item, and 15-item CATs against the full-item banks and to evaluate concurrent validity. Independent samples t tests and analysis of variance were used to evaluate the ability of the daily routine scales to discriminate between children with tetraplegia and paraplegia and among 5 motor groups. RESULTS: ICC and 95% CI demonstrated that simulated 5-, 10-, and 15-item CATs accurately represented the full-item banks for both child- and parent-report scales. The daily routine scales demonstrated discriminative validity, except between 2 motor groups of children with paraplegia. Concurrent validity of the daily routine scales was demonstrated through significant relationships with the FIM scores. CONCLUSION: Child- and parent-reported outcomes of daily routines can be obtained using CATs with the same relative precision of a full-item bank. Five-item, 10-item, and 15-item CATs have discriminative and concurrent validity.

An examination of the PROMIS(®) pediatric instruments to assess mobility in children with cerebral palsy.

PURPOSE: The Patient-Reported Outcomes Measurement Information System (PROMIS(®)) provides adult and pediatric self-report measures of health-related quality of life designed for use across medical conditions and the general population. The purpose of this study was to examine the feasibility and validity of the PROMIS(®) Pediatric Short Form and computer-adaptive test (CAT) mobility measures in children with cerebral palsy (CP). METHODS: Eighty-two children with CP completed self-report (PROMIS(®) Mobility Short Form, PROMIS(®) Mobility CAT, Pediatric Quality of Life Inventory™) and performance-based assessments of mobility (Timed Up and Go, Gross Motor Function Measure). Parents provided three proxy reports of child mobility (Pediatric Outcomes Data Collection Instrument, Functional Assessment Questionnaire, Shriners Hospitals for Children CP-CAT). Validity of PROMIS(®) instruments was examined through correlations with other measures and "known groups" analyses determined by Gross Motor Function Classification System (GMFCS). RESULTS: On average, the PROMIS(®) CAT required less than seven items and 2 minutes to administer. Both PROMIS(®) measures showed moderate to high correlations with child- and parent-proxy report of child mobility; correlations with performance-based measure were small for the PROMIS(®) Short Form and non-significant for the PROMIS(®) CAT. All measures except for the PROMIS(®) CAT were able to distinguish between GMFCS categories. CONCLUSIONS: Results support the convergent and discriminant validity of the pediatric PROMIS(®) Mobility Short Form in children with CP. The PROMIS(®) Mobility CAT correlates well with child report and parent report of mobility but not with performance-based measures and does not differentiate between known mobility groups.

Development of a computer-adaptive physical function instrument for Social Security Administration disability determination.

OBJECTIVES: To develop and test an instrument to assess physical function for Social Security Administration (SSA) disability programs, the SSA-Physical Function (SSA-PF) instrument. Item response theory (IRT) analyses were used to (1) create a calibrated item bank for each of the factors identified in prior factor analyses, (2) assess the fit of the items within each scale, (3) develop separate computer-adaptive testing (CAT) instruments for each scale, and (4) conduct initial psychometric testing. DESIGN: Cross-sectional data collection; IRT analyses; CAT simulation. SETTING: Telephone and Internet survey. PARTICIPANTS: Two samples: SSA claimants (n=1017) and adults from the U.S. general population (n=999). INTERVENTIONS: None. MAIN OUTCOME MEASURES: Model fit statistics, correlation, and reliability coefficients. RESULTS: IRT analyses resulted in 5 unidimensional SSA-PF scales: Changing & Maintaining Body Position, Whole Body Mobility, Upper Body Function, Upper Extremity Fine Motor, and Wheelchair Mobility for a total of 102 items. High CAT accuracy was demonstrated by strong correlations between simulated CAT scores and those from the full item banks. On comparing the simulated CATs with the full item banks, very little loss of reliability or precision was noted, except at the lower and upper ranges of each scale. No difference in response patterns by age or sex was noted. The distributions of claimant scores were shifted to the lower end of each scale compared with those of a sample of U.S. adults. CONCLUSIONS: The SSA-PF instrument contributes important new methodology for measuring the physical function of adults applying to the SSA disability programs. Initial evaluation revealed that the SSA-PF instrument achieved considerable breadth of coverage in each content domain and demonstrated noteworthy psychometric properties.

Development of an instrument to measure behavioral health function for work disability: item pool construction and factor analysis.

OBJECTIVES: To develop a broad set of claimant-reported items to assess behavioral health functioning relevant to the Social Security disability determination processes, and to evaluate the underlying structure of behavioral health functioning for use in development of a new functional assessment instrument. DESIGN: Cross-sectional. SETTING: Community. PARTICIPANTS: Item pools of behavioral health functioning were developed, refined, and field tested in a sample of persons applying for Social Security disability benefits (N=1015) who reported difficulties working because of mental or both mental and physical conditions. INTERVENTIONS: None. MAIN OUTCOME MEASURE: Social Security Administration Behavioral Health (SSA-BH) measurement instrument. RESULTS: Confirmatory factor analysis (CFA) specified that a 4-factor model (self-efficacy, mood and emotions, behavioral control, social interactions) had the optimal fit with the data and was also consistent with our hypothesized conceptual framework for characterizing behavioral health functioning. When the items within each of the 4 scales were tested in CFA, the fit statistics indicated adequate support for characterizing behavioral health as a unidimensional construct along these 4 distinct scales of function. CONCLUSIONS: This work represents a significant advance both conceptually and psychometrically in assessment methodologies for work-related behavioral health. The measurement of behavioral health functioning relevant to the context of work requires the assessment of multiple dimensions of behavioral health functioning. Specifically, we identified a 4-factor model solution that represented key domains of work-related behavioral health functioning. These results guided the development and scale formation of a new SSA-BH instrument.

Conceptual foundation for measures of physical function and behavioral health function for Social Security work disability evaluation.

Physical and mental impairments represent the 2 largest health condition categories for which workers receive Social Security disability benefits. Comprehensive assessment of physical and mental impairments should include aspects beyond medical conditions such as a person's underlying capabilities as well as activity demands relevant to the context of work. The objective of this article is to describe the initial conceptual stages of developing new measurement instruments of behavioral health and physical functioning relevant for Social Security work disability evaluation purposes. To outline a clear conceptualization of the constructs to be measured, 2 content models were developed using structured and informal qualitative approaches. We performed a structured literature review focusing on work disability and incorporating aspects of the International Classification of Functioning, Disability and Health as a unifying taxonomy for framework development. Expert interviews provided advice and consultation to enhance face validity of the resulting content models. The content model for work-related behavioral health function identifies 5 major domains: (1) behavior control, (2) basic interactions, (3) temperament and personality, (4) adaptability, and (5) workplace behaviors. The content model describing physical functioning includes 3 domains: (1) changing and maintaining body position, (2) whole-body mobility, and (3) carrying, moving, and handling objects. These content models informed subsequent measurement properties including item development and measurement scale construction, and provided conceptual coherence guiding future empirical inquiry. The proposed measurement approaches show promise to comprehensively and systematically assess physical and behavioral health functioning relevant to work.

Development of a self-report physical function instrument for disability assessment: item pool construction and factor analysis.

OBJECTIVES: To build a comprehensive item pool representing work-relevant physical functioning and to test the factor structure of the item pool. These developmental steps represent initial outcomes of a broader project to develop instruments for the assessment of function within the context of Social Security Administration (SSA) disability programs. DESIGN: Comprehensive literature review; gap analysis; item generation with expert panel input; stakeholder interviews; cognitive interviews; cross-sectional survey administration; and exploratory and confirmatory factor analyses to assess item pool structure. SETTING: In-person and semistructured interviews and Internet and telephone surveys. PARTICIPANTS: Sample of SSA claimants (n=1017) and a normative sample of adults from the U.S. general population (n=999). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: Model fit statistics. RESULTS: The final item pool consisted of 139 items. Within the claimant sample, 58.7% were white; 31.8% were black; 46.6% were women; and the mean age was 49.7 years. Initial factor analyses revealed a 4-factor solution, which included more items and allowed separate characterization of: (1) changing and maintaining body position, (2) whole body mobility, (3) upper body function, and (4) upper extremity fine motor. The final 4-factor model included 91 items. Confirmatory factor analyses for the 4-factor models for the claimant and the normative samples demonstrated very good fit. Fit statistics for claimant and normative samples, respectively, were: Comparative Fit Index=.93 and .98; Tucker-Lewis Index=.92 and .98; and root mean square error approximation=.05 and .04. CONCLUSIONS: The factor structure of the physical function item pool closely resembled the hypothesized content model. The 4 scales relevant to work activities offer promise for providing reliable information about claimant physical functioning relevant to work disability.

Scale refinement and initial evaluation of a behavioral health function measurement tool for work disability evaluation.

OBJECTIVE: To use item response theory (IRT) data simulations to construct and perform initial psychometric testing of a newly developed instrument, the Social Security Administration Behavioral Health Function (SSA-BH) instrument, that aims to assess behavioral health functioning relevant to the context of work. DESIGN: Cross-sectional survey followed by IRT calibration data simulations. SETTING: Community. PARTICIPANTS: Sample of individuals applying for Social Security Administration disability benefits: claimants (n=1015) and a normative comparative sample of U.S. adults (n=1000). INTERVENTIONS: None. MAIN OUTCOME MEASURE: SSA-BH measurement instrument. RESULTS: IRT analyses supported the unidimensionality of 4 SSA-BH scales: mood and emotions (35 items), self-efficacy (23 items), social interactions (6 items), and behavioral control (15 items). All SSA-BH scales demonstrated strong psychometric properties including reliability, accuracy, and breadth of coverage. High correlations of the simulated 5- or 10-item computer adaptive tests with the full item bank indicated robust ability of the computer adaptive testing approach to comprehensively characterize behavioral health function along 4 distinct dimensions. CONCLUSIONS: Initial testing and evaluation of the SSA-BH instrument demonstrated good accuracy, reliability, and content coverage along all 4 scales. Behavioral function profiles of Social Security Administration claimants were generated and compared with age- and sex-matched norms along 4 scales: mood and emotions, behavioral control, social interactions, and self-efficacy. Using the computer adaptive test-based approach offers the ability to collect standardized, comprehensive functional information about claimants in an efficient way, which may prove useful in the context of the Social Security Administration's work disability programs.

A preliminary evaluation of the PEDI-CAT Mobility item bank for children using walking aids and wheelchairs.

OBJECTIVE: To examine the discriminant validity and scoring patterns of the PEDI-CAT Mobility item bank for children who use a walking aid or wheelchair. METHODS: Parents whose children use a walking aid (n=35) or a wheelchair (n=31) completed the full PEDI-CAT Mobility item bank (105 items including 13 walking aid and 14 wheelchair items) on-line. An independent sample t-test was used to examine mean scores between the groups. Point spread and placement of the scores along the overall 20-80 test scale and response patterns for the 27 mobility device items were analyzed descriptively. RESULTS: Mean scaled scores were significantly different (p < 0.001) for the two groups. Mean score for the Wheelchair Group (38.37, SD=7.09) was lower than the Walking Aid Group (46.97, SD=5.10). The Walking Aid Group started and ended higher on the 20 to 80 scale metric than the Wheelchair Group. No floor or ceiling effects were seen for the scoring of the 27 items specifying use of a mobility device. CONCLUSION: The %scores of the PEDI-CAT Mobility domain could differentiate the functional mobility status between known groups of children who use a walking aid or wheelchair and provides specific items to measure functional mobility with use of a mobility device.

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.