Care Partners' Engagement in Preventing Falls for Community-Dwelling Older People With Dementia.

BACKGROUND AND OBJECTIVES: Little is known about how to prevent falls in community-dwelling older people with dementia. Although their care partners adopt various behaviors to prevent their falls, it is unclear if these behaviors reduce falls for those with different levels of fall risk. RESEARCH DESIGN AND METHODS: Linking the 2015 and 2016 National Health and Aging Trends Study and the 2015 National Study of Caregiving (NSOC), we identified 390 community-dwelling older people with dementia with 607 care partners. We selected 26 NSOC items representing fall risk management (FRM) behaviors. We examined the prevalence and dimensionality of these behaviors and investigated associations between care partners' behaviors in 2015 (T1) and older people's falls in 2016 (T2) stratified by their fall incidence at T1, adjusting for covariates. RESULTS: Five domains of FRM were identified: mobility and safety assistance, medical service coordination, health management, social service coordination, and accommodation. For those who did not fall at T1, mobility and safety assistance and social service coordination were each associated with an increased risk of falling at T2 (adjusted incidence rate ratio [aIRR] = 1.39, 95% confidence interval [CI] = 1.06-1.83, p = .019, aIRR = 1.25, 95% CI = 1.01-1.55, p = .043). For those who had fallen at T1, social service coordination was associated with a decreased risk of falling at T2 (aIRR = 0.83, 95% CI = 0.73-0.94, p = .004). DISCUSSION AND IMPLICATIONS: The different impacts of dementia care partners' FRM behaviors emphasize the need to address specific behaviors when involving care partners in preventing falls for older people with dementia at varying levels of fall risk.

DIF Detection With Zero-Inflation Under the Factor Mixture Modeling Framework.

Response data containing an excessive number of zeros are referred to as zero-inflated data. When differential item functioning (DIF) detection is of interest, zero-inflation can attenuate DIF effects in the total sample and lead to underdetection of DIF items. The current study presents a DIF detection procedure for response data with excess zeros due to the existence of unobserved heterogeneous subgroups. The suggested procedure utilizes the factor mixture modeling (FMM) with MIMIC (multiple-indicator multiple-cause) to address the compromised DIF detection power via the estimation of latent classes. A Monte Carlo simulation was conducted to evaluate the suggested procedure in comparison to the well-known likelihood ratio (LR) DIF test. Our simulation study results indicated the superiority of FMM over the LR DIF test in terms of detection power and illustrated the importance of accounting for latent heterogeneity in zero-inflated data. The empirical data analysis results further supported the use of FMM by flagging additional DIF items over and above the LR test.

maat: An R Package for Multiple Administrations Adaptive Testing.

Multiple Administrations Adaptive Testing (MAAT) is an extension of the shadow-test approach to CAT for the assessment framework involving multiple tests administered periodically throughout the year. The maat package utilizes multiple item pools vertically scaled across grades and multiple phases (stages) within each test administration, allowing for transitioning from an item pool to another as deemed necessary to further enhance the quality of assessment.

Linking Scores with Patient-Reported Health Outcome Instruments:A VALIDATION STUDY AND COMPARISON OF THREE LINKING METHODS.

The psychometric process used to establish a relationship between the scores of two (or more) instruments is generically referred to as linking. When two instruments with the same content and statistical test specifications are linked, these instruments are said to be equated. Linking and equating procedures have long been used for practical benefit in educational testing. In recent years, health outcome researchers have increasingly applied linking techniques to patient-reported outcome (PRO) data. However, these applications have some noteworthy purposes and associated methodological questions. Purposes for linking health outcomes include the harmonization of data across studies or settings (enabling increased power in hypothesis testing), the aggregation of summed score data by means of score crosswalk tables, and score conversion in clinical settings where new instruments are introduced, but an interpretable connection to historical data is needed. When two PRO instruments are linked, assumptions for equating are typically not met and the extent to which those assumptions are violated becomes a decision point around how (and whether) to proceed with linking. We demonstrate multiple linking procedures-equipercentile, unidimensional IRT calibration, and calibrated projection-with the Patient-Reported Outcomes Measurement Information System Depression bank and the Patient Health Questionnaire-9. We validate this link across two samples and simulate different instrument correlation levels to provide guidance around which linking method is preferred. Finally, we discuss some remaining issues and directions for psychometric research in linking PRO instruments.

Efficacy and tolerability of febuxostat in gout patients on dialysis.

BACKGROUND: There are no sufficient data available on the use of febuxostat in patients undergoing dialysis. AIM: To investigate the efficacy and tolerability of febuxostat in gout patients on dialysis. METHODS: We retrospectively reviewed clinical and laboratory data available from a referral centre from January 2012 to December 2018. We included gout patients who initiated febuxostat during dialysis. Data regarding serum uric acid levels before and after the febuxostat treatment and clinical information such as gout attack after febuxostat initiation, as well as adverse events involving febuxostat treatment, were obtained from medical records. RESULTS: Among 62 patients who were treated with febuxostat for over 3 months, 45 were undergoing haemodialysis (HD) and 17 were undergoing peritoneal dialysis (PD). The mean serum uric acid level was significantly reduced 3 months after treatment (3.71 ± 1.32 mg/dL) compared with that at the pretreatment level (9.36 ± 2.06 mg/dL) (P < 0.001). The serum uric acid level was observed to be significantly reduced at 3 months in both HD and PD patients and subsequently remained at a significantly reduced level for 12 months. Of the 62 patients, only two stopped febuxostat due to its adverse effects. Initial dose of 80 mg/day was associated with higher adverse events compared to dose of 20-40 mg/day (odds ratio 8.25, 95% confidence interval 1.90-35.97, P = 0.006). CONCLUSIONS: Febuxostat is efficacious and well tolerated in gout patients on dialysis. Febuxostat taken at dose of 20-40 mg/day might be appropriate initial dose in patients undergoing dialysis.

Validation of a Short Form for Health Literacy Assessment Using Talking Touchscreen Technology.

BACKGROUND: Health literacy is an area of growing research and clinical interest, necessitating short, accurate measures of this complex construct. Health Literacy Assessment Using Talking Touchscreen Technology (Health LiTT) measures prose, document, and quantitative literacy by self-administration on a touchscreen computer. OBJECTIVE: The objective of this study was to assess the validity of a short form of Health LiTT and to identify a meaningful cutoff score for adequate health literacy. METHODS: A subsample of 137 participants from the Literacy and Cognitive Function among Older Adults study completed a 10-item Health LiTT short form and three interviewer-administered health literacy measures: Test of Functional Health Literacy in Adults (TOFHLA), Rapid Estimate of Adult Literacy in Medicine (REALM), and Newest Vital Sign (NVS). Convergent validity was assessed by correlating scores for all measures, and known-groups validity was assessed by comparing mean Health LITT scores across TOFHLA levels (inadequate, marginal, adequate). Internal consistency reliability was estimated with Cronbach's alpha. A cutoff score for adequate health literacy was established using the TOFHLA cutoff for adequate versus inadequate/marginal health literacy. KEY RESULTS: Spearman correlations between Health LiTT scores and total TOFHLA, REALM, and NVS scores were 0.65, 0.69, and 0.56, respectively (all p < .001). Mean Health LiTT scores were significantly and meaningfully different across inadequate (40.4), marginal (50.1), and adequate (57.1) TOFHLA categories (F = 60.6; p < .001). Cronbach's alpha for the Health LiTT short form was .73. A cutoff score of 55 on Health LiTT showed acceptable sensitivity and specificity to identify adequate health literacy. CONCLUSIONS: This 10-item Health LiTT short form demonstrated excellent convergent and known-groups validity and acceptable internal consistency reliability in older adults. The established cutoff also showed excellent sensitivity and specificity. Validation of other custom Health LiTT short forms with varying items from the bank and computer adaptive test-generated Health LiTT scores is ongoing. [HLRP: Health Literacy Research and Practice. 2020;4(4):e200-e207.] PLAIN LANGUAGE SUMMARY: This article provides evidence of the need for and psychometric properties of a valid and reliable short form of the flexible, technologically advanced Health Literacy Assessment Using Talking Touchscreen Technology measure, as well as a cutoff score to note adequate versus marginal/inadequate health literacy.

Measuring Self-Reported Physical Function in Individuals With TBI: Development of the TBI-QOL Mobility and Upper Extremity Item Banks and Short Forms.

OBJECTIVES: To describe the development and field testing of the patient-reported outcome measures of Mobility and Upper Extremity function from the Traumatic Brain Injury Quality of Life (TBI-QOL) measurement system, and to evaluate the use of computer adaptive testing. SETTING: Five rehabilitation facilities funded as part of the TBI Model Systems network. PARTICIPANTS: Individuals with complicated mild, moderate, or severe traumatic brain injury (n = 590). INTERVENTIONS: Not available. OUTCOME MEASURES: TBI-QOL Mobility and Upper Extremity item banks. RESULTS: Item response theory and factor analyses supported the unidimensionality of the Mobility and Upper Extremity banks. Descriptive statistics showed a ceiling effect for both measures. Simulated computer adaptive tests (CATs) showed that measurement precision was maintained across administration formats for both measures. The Upper Extremity CAT showed a loss of precision for individuals without impairment and that a higher number of items were required to achieve sufficiently precise measurement, compared to the Mobility CAT. CONCLUSIONS: The TBI-QOL Upper Extremity and Mobility item banks achieved good breadth of coverage, particularly among those individuals who have experienced some degree of functional limitation. The use of CAT administration minimizes respondent burden, while allowing for the comprehensive assessment of adults with TBI. The combined use of the TBI-QOL with performance-based measures could guide the development of targeted rehabilitation treatments.

Linking the GAD-7 and PHQ-9 to the TBI-QOL Anxiety and Depression Item Banks.

OBJECTIVE: To link scores on commonly used measures of anxiety (7-item Generalized Anxiety Disorder Scale; GAD-7) and depression (9-item Patient Health Questionnaire; PHQ-9) to the Traumatic Brain Injury Quality of Life (TBI-QOL) measurement system. SETTING: 5 Traumatic Brain Injury Model Systems. PARTICIPANTS: A total of 385 individuals with traumatic brain injury (TBI) (31% complicated mild; 14% moderate; and 54% severe). DESIGN: Observational cohort. MAIN MEASURES: GAD-7, PHQ-9, TBI-QOL Anxiety v1.0 and TBI-QOL Depression v1.0. RESULTS: Item response theory-based linking methods were used to create crosswalk tables that convert scores on the GAD-7 to the TBI-QOL Anxiety metric and scores on the PHQ-9 to the TBI-QOL Depression metric. Comparisons between actual and crosswalked scores suggest that the linkages were successful and are appropriate for group-level analysis. Linking functions closely mirror crosswalks between the GAD-7/PHQ-9 and the Patient-Reported Outcomes Measurement Information System (PROMIS), suggesting that general population linkages are similar to those from a TBI sample. CONCLUSION: Researchers and clinicians can use the crosswalk tables to transform scores on the GAD-7 and the PHQ-9 to the TBI-QOL metric for group-level analyses.

PROMIS® Adult Health Profiles: Efficient Short-Form Measures of Seven Health Domains.

BACKGROUND: There is a need for valid self-report measures of core health-related quality of life (HRQoL) domains. OBJECTIVE: To derive brief, reliable and valid health profile measures from the Patient Reported Outcomes Measurement Information System® (PROMIS®) item banks. METHODS: Literature review, investigator consensus process, item response theory (IRT) analysis, and expert review of scaling results from multiple PROMIS data sets. We developed 3 profile measures ranging in length from 29 to 57 questions. These profiles assess important HRQoL domains with highly informative subsets of items from respective item banks and yield reliable information across mild-to-severe levels of HRQoL experiences. Each instrument assesses the domains of pain interference, fatigue, depression, anxiety, sleep disturbance, physical function, and social function using 4-, 6-, and 8-item short forms for each domain, and an average pain intensity domain score, using a 0-10 numeric rating scale. RESULTS: With few exceptions, all domain short forms within the profile measures were highly reliable across at least 3 standard deviation (30 T-score) units and were strongly correlated with the full bank scores. Construct validity with ratings of general health and quality of life was demonstrated. Information to inform statistical power for clinical and general population samples is also provided. CONCLUSIONS: Although these profile measures have been used widely, with summary scoring routines published, description of their development, reliability, and initial validity has not been published until this article. Further evaluation of these measures and clinical applications are encouraged.

Ensuring content validity of patient-reported outcomes: a shadow-test approach to their adaptive measurement.

PURPOSE: Most computerized adaptive testing (CAT) applications in patient-reported outcomes (PRO) measurement to date are reliability-centric, with a primary objective of maximizing measurement efficiency. A key concern and a potential threat to validity is that, when left unconstrained, individual CAT administrations could have items with systematically different attributes, e.g., sub-domain coverage. This paper aims to provide a solution to the problem from an optimal test design framework using the shadow-test approach to CAT. METHODS: Following the approach, a case study was conducted using the PROMIS® (Patient-Reported Outcomes Measurement Information System) fatigue item bank both with empirical and simulated response data. Comparisons between CAT administrations without and with the enforcement of content and item pool usage constraints were examined. RESULTS: The unconstrained CAT exhibited a high degree of variation in items selected from different substrata of the item bank. Contrastingly, the shadow-test approach delivered CAT administrations conforming to all specifications with a minimal loss in measurement efficiency. CONCLUSIONS: The optimal test design and shadow-test approach to CAT provide a flexible framework for solving complex test-assembly problems with better control of their domain coverage than for the conventional use of CAT in PRO measurement. Applications in a wide array of PRO domains are expected to lead to more controlled and balanced use of CAT in the field.

Do measures of depressive symptoms function differently in people with spinal cord injury versus primary care patients: the CES-D, PHQ-9, and PROMIS®-D.

PURPOSE: To evaluate whether items of three measures of depressive symptoms function differently in persons with spinal cord injury (SCI) than in persons from a primary care sample. METHODS: This study was a retrospective analysis of responses to the Patient Health Questionnaire depression scale, the Center for Epidemiological Studies Depression scale, and the National Institutes of Health Patient-Reported Outcomes Measurement Information System (PROMIS®) version 1.0 eight-item depression short form 8b (PROMIS-D). The presence of differential item function (DIF) was evaluated using ordinal logistic regression. RESULTS: No items of any of the three target measures were flagged for DIF based on standard criteria. In a follow-up sensitivity analyses, the criterion was changed to make the analysis more sensitive to potential DIF. Scores were corrected for DIF flagged under this criterion. Minimal differences were found between the original scores and those corrected for DIF under the sensitivity criterion. CONCLUSIONS: The three depression screening measures evaluated in this study did not perform differently in samples of individuals with SCI compared to general and community samples. Transdiagnostic symptoms did not appear to spuriously inflate depression severity estimates when administered to people with SCI.

Development of a six-factor questionnaire for use in weight management counseling.

OBJECTIVE: To develop and validate a new 6 factor questionnaire (6-FQ) that identifies unhealthful behavioral, cognitive and affective lifestyle pattern factors among a large sample of adults who are overweight or obese. METHODS: Based on a previously developed 53-item lifestyle patterns questionnaire completed by 10,000 subjects, a new 6-FQ was developed and validated by using two prospective subject groups (n=640) with combined mean age of 43±11.4years and BMI 33.8±9.1kg/m2. RESULTS: An exploratory factor analysis and multidimensional scaling were conducted that identified 6 distinct factors with excellent psychometric properties. Cronbach's internal consistency reliability estimates ranged from 0.76 to 0.85. The prevalence rates and odds ratios of the factors are generally and directly related with increasing BMI categories. The 6-FQ is highly correlated with multiple subscales from the co-administered IWQOL-Lite questionnaire. CONCLUSIONS: The 6-FQ is a 27-item self-administered instrument with excellent psychometric properties that measures patients' lifestyle pattern factors. PRACTICE IMPLICATIONS: The 6-FQ is a convenient, short, self-administered instrument that has potential to target patients' self-identified lifestyle patterns related to body weight, and should allow clinicians to efficiently and effectively counsel patients on targeted treatment recommendations.

TBI-QOL: Development and Calibration of Item Banks to Measure Patient Reported Outcomes Following Traumatic Brain Injury.

OBJECTIVE: To use a patient-centered approach or participatory action research design combined with advanced psychometrics to develop a comprehensive patient-reported outcomes (PRO) measurement system specifically for individuals with traumatic brain injury (TBI). This TBI Quality-of-Life (TBI-QOL) measurement system expands the work of other large PRO measurement initiatives, that is, the Patient-Reported Outcomes Measurement Information System and the Neurology Quality-of-Life measurement initiative. SETTING: Five TBI Model Systems centers across the United States. PARTICIPANTS: Adults with TBI. DESIGN: Classical and modern test development methodologies were used. Qualitative input was obtained from individuals with TBI, TBI clinicians, and caregivers of individuals with TBI through multiple methods, including focus groups, individual interviews, patient consultation, and cognitive debriefing interviews. Item pools were field tested in a large multisite sample (n = 675) and calibrated using item response theory methods. MAIN OUTCOMES MEASURES: Twenty-two TBI-QOL item banks/scales. RESULTS: The TBI-QOL consists of 20 independent calibrated item banks and 2 uncalibrated scales that measure physical, emotional, cognitive, and social aspects of health-related quality of life. CONCLUSIONS: The TBI-QOL measurement system has potential as a common data element in TBI research and to enhance collection of health-related quality-of-life and PRO data in rehabilitation research and clinical settings.

Optimal Reassembly of Shadow Tests in CAT.

Even in the age of abundant and fast computing resources, concurrency requirements for large-scale online testing programs still put an uninterrupted delivery of computer-adaptive tests at risk. In this study, to increase the concurrency for operational programs that use the shadow-test approach to adaptive testing, we explored various strategies aiming for reducing the number of reassembled shadow tests without compromising the measurement quality. Strategies requiring fixed intervals between reassemblies, a certain minimal change in the interim ability estimate since the last assembly before triggering a reassembly, and a hybrid of the two strategies yielded substantial reductions in the number of reassemblies without degradation in the measurement accuracy. The strategies effectively prevented unnecessary reassemblies due to adapting to the noise in the early test stages. They also highlighted the practicality of the shadow-test approach by minimizing the computational load involved in its use of mixed-integer programming.

Methodology for the development and calibration of the SCI-QOL item banks.

OBJECTIVE: To develop a comprehensive, psychometrically sound, and conceptually grounded patient reported outcomes (PRO) measurement system for individuals with spinal cord injury (SCI). METHODS: Individual interviews (n=44) and focus groups (n=65 individuals with SCI and n=42 SCI clinicians) were used to select key domains for inclusion and to develop PRO items. Verbatim items from other cutting-edge measurement systems (i.e. PROMIS, Neuro-QOL) were included to facilitate linkage and cross-population comparison. Items were field tested in a large sample of individuals with traumatic SCI (n=877). Dimensionality was assessed with confirmatory factor analysis. Local item dependence and differential item functioning were assessed, and items were calibrated using the item response theory (IRT) graded response model. Finally, computer adaptive tests (CATs) and short forms were administered in a new sample (n=245) to assess test-retest reliability and stability. PARTICIPANTS AND PROCEDURES: A calibration sample of 877 individuals with traumatic SCI across five SCI Model Systems sites and one Department of Veterans Affairs medical center completed SCI-QOL items in interview format. RESULTS: We developed 14 unidimensional calibrated item banks and 3 calibrated scales across physical, emotional, and social health domains. When combined with the five Spinal Cord Injury--Functional Index physical function banks, the final SCI-QOL system consists of 22 IRT-calibrated item banks/scales. Item banks may be administered as CATs or short forms. Scales may be administered in a fixed-length format only. CONCLUSIONS: The SCI-QOL measurement system provides SCI researchers and clinicians with a comprehensive, relevant and psychometrically robust system for measurement of physical-medical, physical-functional, emotional, and social outcomes. All SCI-QOL instruments are freely available on Assessment CenterSM.

Overview of the Spinal Cord Injury--Quality of Life (SCI-QOL) measurement system.

CONTEXT/OBJECTIVE: The Spinal Cord Injury--Quality of Life (SCI-QOL) measurement system was developed to address the shortage of relevant and psychometrically sound patient reported outcome (PRO) measures available for clinical care and research in spinal cord injury (SCI) rehabilitation. Using a computer adaptive testing (CAT) approach, the SCI-QOL builds on the Patient Reported Outcomes Measurement Information System (PROMIS) and the Quality of Life in Neurological Disorders (Neuro-QOL) initiative. This initial manuscript introduces the background and development of the SCI-QOL measurement system. Greater detail is presented in the additional manuscripts of this special issue. DESIGN: Classical and contemporary test development methodologies were employed. Qualitative input was obtained from individuals with SCI and clinicians through interviews, focus groups, and cognitive debriefing. Item pools were field tested in a multi-site sample (n=877) and calibrated using item response theory methods. Initial reliability and validity testing was performed in a new sample of individuals with traumatic SCI (n=245). SETTING: Five Model SCI System centers and one Department of Veterans Affairs Medical Center across the United States. PARTICIPANTS: Adults with traumatic SCI. INTERVENTIONS: n/a OUTCOME MEASURES: n/a RESULTS: The SCI-QOL consists of 19 item banks, including the SCI-Functional Index banks, and 3 fixed-length scales measuring physical, emotional, and social aspects of health-related QOL (HRQOL). CONCLUSION: The SCI-QOL measurement system consists of psychometrically sound measures for individuals with SCI. The manuscripts in this special issue provide evidence of the reliability and initial validity of this measurement system. The SCI-QOL also links to other measures designed for a general medical population.

Development and psychometric characteristics of the SCI-QOL Pressure Ulcers scale and short form.

OBJECTIVE: To develop a self-reported measure of the subjective impact of pressure ulcers on health-related quality of life (HRQOL) in individuals with spinal cord injury (SCI) as part of the SCI quality of life (SCI-QOL) measurement system. DESIGN: Grounded-theory based qualitative item development methods, large-scale item calibration testing, confirmatory factor analysis (CFA), and item response theory-based psychometric analysis. SETTING: Five SCI Model System centers and one Department of Veterans Affairs medical center in the United States. PARTICIPANTS: Adults with traumatic SCI. MAIN OUTCOME MEASURES: SCI-QOL Pressure Ulcers scale. RESULTS: 189 individuals with traumatic SCI who experienced a pressure ulcer within the past 7 days completed 30 items related to pressure ulcers. CFA confirmed a unidimensional pool of items. IRT analyses were conducted. A constrained Graded Response Model with a constant slope parameter was used to estimate item thresholds for the 12 retained items. CONCLUSIONS: The 12-item SCI-QOL Pressure Ulcers scale is unique in that it is specifically targeted to individuals with spinal cord injury and at every stage of development has included input from individuals with SCI. Furthermore, use of CFA and IRT methods provide flexibility and precision of measurement. The scale may be administered in its entirety or as a 7-item "short form" and is available for both research and clinical practice.

Measuring anxiety after spinal cord injury: Development and psychometric characteristics of the SCI-QOL Anxiety item bank and linkage with GAD-7.

OBJECTIVE: To develop a calibrated item bank and computer adaptive test to assess anxiety symptoms in individuals with spinal cord injury (SCI), transform scores to the Patient Reported Outcomes Measurement Information System (PROMIS) metric, and create a statistical linkage with the Generalized Anxiety Disorder (GAD)-7, a widely used anxiety measure. DESIGN: Grounded-theory based qualitative item development methods; large-scale item calibration field testing; confirmatory factor analysis; graded response model item response theory analyses; statistical linking techniques to transform scores to a PROMIS metric; and linkage with the GAD-7. Setting Five SCI Model System centers and one Department of Veterans Affairs medical center in the United States. Participants Adults with traumatic SCI. MAIN OUTCOME MEASURES: Spinal Cord Injury-Quality of Life (SCI-QOL) Anxiety Item Bank RESULTS: Seven hundred sixteen individuals with traumatic SCI completed 38 items assessing anxiety, 17 of which were PROMIS items. After 13 items (including 2 PROMIS items) were removed, factor analyses confirmed unidimensionality. Item response theory analyses were used to estimate slopes and thresholds for the final 25 items (15 from PROMIS). The observed Pearson correlation between the SCI-QOL Anxiety and GAD-7 scores was 0.67. CONCLUSIONS: The SCI-QOL Anxiety item bank demonstrates excellent psychometric properties and is available as a computer adaptive test or short form for research and clinical applications. SCI-QOL Anxiety scores have been transformed to the PROMIS metric and we provide a method to link SCI-QOL Anxiety scores with those of the GAD-7.

Measuring psychological trauma after spinal cord injury: Development and psychometric characteristics of the SCI-QOL Psychological Trauma item bank and short form.

OBJECTIVE: To describe the development and psychometric properties of the SCI-QOL Psychological Trauma item bank and short form. DESIGN: Using a mixed-methods design, we developed and tested a Psychological Trauma item bank with patient and provider focus groups, cognitive interviews, and item response theory based analytic approaches, including tests of model fit, differential item functioning (DIF) and precision. SETTING: We tested a 31-item pool at several medical institutions across the United States, including the University of Michigan, Kessler Foundation, Rehabilitation Institute of Chicago, the University of Washington, Craig Hospital and the James J. Peters/Bronx Veterans Administration hospital. PARTICIPANTS: A total of 716 individuals with SCI completed the trauma items RESULTS: The 31 items fit a unidimensional model (CFI=0.952; RMSEA=0.061) and demonstrated good precision (theta range between 0.6 and 2.5). Nine items demonstrated negligible DIF with little impact on score estimates. The final calibrated item bank contains 19 items CONCLUSION: The SCI-QOL Psychological Trauma item bank is a psychometrically robust measurement tool from which a short form and a computer adaptive test (CAT) version are available.

Measuring depression after spinal cord injury: Development and psychometric characteristics of the SCI-QOL Depression item bank and linkage with PHQ-9.

OBJECTIVE: To develop a calibrated spinal cord injury-quality of life (SCI-QOL) item bank, computer adaptive test (CAT), and short form to assess depressive symptoms experienced by individuals with SCI, transform scores to the Patient Reported Outcomes Measurement Information System (PROMIS) metric, and create a crosswalk to the Patient Health Questionnaire (PHQ)-9. DESIGN: We used grounded-theory based qualitative item development methods, large-scale item calibration field testing, confirmatory factor analysis, item response theory (IRT) analyses, and statistical linking techniques to transform scores to a PROMIS metric and to provide a crosswalk with the PHQ-9. SETTING: Five SCI Model System centers and one Department of Veterans Affairs medical center in the United States. PARTICIPANTS: Adults with traumatic SCI. MAIN OUTCOME MEASURES: Spinal Cord Injury--Quality of Life (SCI-QOL) Depression Item Bank RESULTS: Individuals with SCI were involved in all phases of SCI-QOL development. A sample of 716 individuals with traumatic SCI completed 35 items assessing depression, 18 of which were PROMIS items. After removing 7 non-PROMIS items, factor analyses confirmed a unidimensional pool of items. We used a graded response IRT model to estimate slopes and thresholds for the 28 retained items. The SCI-QOL Depression measure correlated 0.76 with the PHQ-9. CONCLUSIONS: The SCI-QOL Depression item bank provides a reliable and sensitive measure of depressive symptoms with scores reported in terms of general population norms. We provide a crosswalk to the PHQ-9 to facilitate comparisons between measures. The item bank may be administered as a CAT or as a short form and is suitable for research and clinical applications.