Computerized Adaptive Testing Simulation Research Articles

Optimizing Oxford Shoulder Scores with computerized adaptive testing reduces redundancy while maintaining precision.

The Oxford Shoulder Score (OSS) is a 12-item measure commonly used for the assessment of shoulder surgeries. This study explores whether computerized adaptive testing (CAT) provides a shortened, individually tailored questionnaire while maintaining test accuracy. A total of 16,238 preoperative OSS were available in the National Joint Registry (NJR) for England, Wales, Northern Ireland, the Isle of Man, and the States of Guernsey dataset (April 2012 to April 2022). Prior to CAT, the foundational item response theory (IRT) assumptions of unidimensionality, monotonicity, and local independence were established. CAT compared sequential item selection with stopping criteria set at standard error (SE) < 0.32 and SE < 0.45 (equivalent to reliability coefficients of 0.90 and 0.80) to full-length patient-reported outcome measure (PROM) precision. Confirmatory factor analysis (CFA) for unidimensionality exhibited satisfactory fit with root mean square standardized residual (RSMSR) of 0.06 (cut-off ≤ 0.08) but not with comparative fit index (CFI) of 0.85 or Tucker-Lewis index (TLI) of 0.82 (cut-off > 0.90). Monotonicity, measured by H value, yielded 0.482, signifying good monotonic trends. Local independence was generally met, with Yen's Q3 statistic > 0.2 for most items. The median item count for completing the CAT simulation with a SE of 0.32 was 3 (IQR 3 to 12), while for a SE of 0.45 it was 2 (IQR 2 to 6). This constituted only 25% and 16%, respectively, when compared to the 12-item full-length questionnaire. Calibrating IRT for the OSS has resulted in the development of an efficient and shortened CAT while maintaining accuracy and reliability. Through the reduction of redundant items and implementation of a standardized measurement scale, our study highlights a promising approach to alleviate time burden and potentially enhance compliance with these widely used outcome measures.

Item response theory and computer adaptive testing of the sexual knowledge scale of the sexual knowledge and attitude test in a college sample

ABSTRACT Our study addresses the limited availability of well-validated scales for assessing general sexual knowledge among college populations. To fill this gap, we examined the psychometric properties of a 41-item sexual knowledge scale derived from the Sexual Knowledge and Attitudes Test – Adolescents (SKAT-A) in a sample of young adults aged 18–25 (N = 1,291). We employed classical test theory (CTT) procedures, followed by item response theory (IRT) and computerized adaptive testing (CAT), to refine the SKAT-A knowledge scale. Both CTT and IRT analyses identified six items for removal due to poor discrimination and difficulty parameters. A confirmatory factor analysis supported a well-defined unidimensional latent trait of sexual knowledge. The results of CAT simulations using dynamic item administration demonstrated the scale’s measurement precision, with moderate test reliability and relatively low standard errors. On average, there was a 54.3% reduction in the number of items administered without compromising scale reliability. This study concludes that the SKAT-A efficiently assesses a unidimensional trait of sexual knowledge in college-attending young adults. It highlights that only a subset of items from the full test bank is necessary to achieve this, providing a practical and reliable tool for assessing sexual knowledge in this population.

Developing Computerized Adaptive Testing for a National Health Professionals Exam: An Attempt from Psychometric Simulations.

The accurate assessment of health professionals' competence is critical for ensuring public health safety and quality of care. Computerized Adaptive Testing (CAT) based on the Item Response Theory (IRT) has the potential to improve measurement accuracy and reduce respondent burden. In this study, we conducted psychometric simulations to develop a CAT for evaluating the candidates' competence of health professionals. The initial CAT item bank was sourced from the Standardized Competence Test for Clinical Medicine Undergraduates (SCTCMU), a nationwide summative test in China, consisting of 300 multiple-choice items. We randomly selected response data from 2000 Chinese clinical medicine undergraduates for analysis. Two types of analyses were performed: first, evaluating the psychometric properties of all items to meet the requirements of CAT; and second, conducting multiple CAT simulations using both simulated and real response data. The final CAT item bank consisted of 121 items, for which item parameters were calculated using a two-parameter logistic model (2PLM). The CAT simulations, based on both simulated and real data, revealed sufficient marginal reliability (coefficient of marginal reliability above 0.750) and criterion-related validity (Pearson's correlations between CAT scores and aggregate scores of the SCTCMU exceeding 0.850). In national-level medical education assessment, there is an increasing need for concise yet valid evaluations of candidates' competence of health professionals. The CAT developed in this study demonstrated satisfactory reliability and validity, offering a more efficient assessment of candidates' competence of health professionals. The psychometric properties of the CAT could lead to shorter test durations, reduced information loss, and a decreased testing burden for participants.

Applying computerized adaptive testing to the Desires for Speed Questionnaire in the Chinese population: A simulation study.

The current methods for measuring patient-reported outcomes for amphetamine (speed) craving have limitation ability to adapt to the needs of individual patients while maintaining consistency in their scores. This study aimed to investigate whether the 40-item Desires for Speed Questionnaire (DSQ) could be improved for assessing clinical subjects using computerized adaptive testing (CAT). A sample of 677 participants from four drug addiction treatment centers in China was utilized in the study. Two types of analysis were conducted using the response data. First, the psychometric properties of all items were evaluated to meet the requirements of CAT. Second, multiple CAT simulations were carried out using real response data. The results indicated that the CAT method, which only required a small number of items (50%-75%), produced results that were only slightly different from the full DSQ assessment in terms of measuring amphetamine craving and criterion validity. In conclusion, this study suggests that developing a DSQ CAT for clinical subjects is useful as it leads to more efficient measurement without compromising the reliability of the test outcomes. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Development of the PREMIUM computerized adaptive testing for measuring the access and care coordination for patients with severe mental illness

Severe mental illness (SMI) patients often have complex health needs, which makes it difficult to access and coordinate their care. This study aimed to develop a computerized adaptive testing (CAT) tool, PREMIUM CAT-ACC, to measure SMI patients' experience with access and care coordination. This multicenter and cross-sectional study included 496 adult in- and out-patients with SMI (i.e., schizophrenia, bipolar disorder, or major depressive disorder). Psychometric analysis of the 13-item bank showed adequate properties, with preliminary evidence of external validity and no substantial differential item functioning for sex, age, care setting, and diagnosis, making it suitable for CAT administration. A post-hoc CAT simulation demonstrated that the tool was efficient and accurate, with an average of seven items, compared to the full item bank administration. Its use by clinicians can contribute to optimizing patient care pathways and transitioning towards more person-centered healthcare.

The Relation of Item Difficulty Between Classical Test Theory and Item Response Theory: Computerized Adaptive Test Perspective

This study aims to transform the calculated item difficulty statistics according to Classical Test Theory (CTT) into the item difficulty parameter of Item Response Theory (IRT) by utilizing the normal distribution curve and to analyze the effectiveness of this transformation based on Rasch model. In this regard, 36 different data sets created with catR package were studied. For each data set, item difficulty parameters and transformed item difficulty parameters were calculated and the correlation coefficients between these parameters were analyzed. Then, Computerized Adaptive Test (CAT) simulations were performed using these parameters. According to the simulation results, the correlation coefficients between the estimated theta values with both methods were high. Furthermore, in CAT simulations in which both parameters were used, especially in the samples which were over 250, it was found to have similar bias, RMSE values, and the average number of administered items.

Measuring glaucoma quality of life in an Asian population using item banking: psychometric evaluation and computerized adaptive testing simulations.

To assess the psychometric properties of glaucoma-specific health-related quality of life (HRQoL) item banks (IBs), and explore their efficiency using computerized adaptive testing (CAT) simulations. In this cross-sectional, clinical study, 300 Asian glaucoma patients answered 221 items within seven IBs: Ocular Comfort Symptoms (OS); Activity Limitation (AL); Lighting (LT); Mobility (MB); Glaucoma Management (GM); Psychosocial (PSY); and Work (WK). Rasch analysis was conducted to assess each IB's psychometric properties (e.g., item "fit" to the construct; unidimensionality) and a set of analytic performance criteria guiding decision making relating to retaining or dropping domains and items was employed. CAT simulations determined the mean number of items for 'high' and 'moderate' measurement precision (stopping rule: SEM 0.3 and 0.387, respectively). Participants' mean age was 67.2 ± 9.2years (62% male; 87% Chinese). LT, MB, and GM displayed good psychometric properties overall. To optimize AL's psychometric properties, 16 items were deleted due to poor "fit", high missing data, item bias, low discrimination and/or a low clinical/patient importance rating. To resolve multidimensionality in PSY, we rehomed 16 items into a "Concern (CN)" domain. PSY and CN required further amendment, including collapsing of response categories, and removal of poorly functioning items (N = 7). Due to poor measurement precision, low applicability and high ceiling effect, low test information indices, and low item separation index the WK IB was not considered further. In CAT simulations on the final seven IBs (n = 182 items total), an average of 12.1 and 15.7 items per IB were required for moderate and high precision measurement, respectively. After reengineering our seven IBs, they displayed robust psychometric properties and good efficiency in CAT simulations. Once finalized, GlauCAT™-Asian may enable comprehensive assessment of the HRQoL impact of glaucoma and associated treatments.

Detecting Differential Item Functioning in CAT Using IRT Residual DIF Approach

AbstractThe residual differential item functioning (RDIF) detection framework was developed recently under a linear testing context. To explore the potential application of this framework to computerized adaptive testing (CAT), the present study investigated the utility of the RDIFR statistic both as an index for detecting uniform DIF of pretest items in CAT and as a direct measure of the effect size of uniform DIF. Extensive CAT simulations revealed RDIFR to have well‐controlled Type I error and slightly higher power to detect uniform DIF compared with CATSIB, especially when pretest items were calibrated using fixed‐item parameter calibration. Moreover, RDIFR accurately estimated the amount of uniform DIF irrespective of the presence of impact. Therefore, RDIFR demonstrates its potential as a useful tool for evaluating both the statistical and practical significance of uniform DIF in CAT.

Applicability and Efficiency of a Polytomous IRT-Based Computerized Adaptive Test for Measuring Psychological Traits

Currently, research on computerized adaptive testing (CAT) focuses mainly on dichotomous items and cognitive traits (achievement, aptitude, etc.). However, polytomous IRT-based CAT is a promising research area for measuring psychological traits that has attracted much attention. The main purpose of this study is to test the practicality of the polytomous IRT-based CAT and its equivalence with the paper-pencil version. Data were collected from 1449 high school students (45% female) via the paper-pencil version. The data were used for IRT parameter estimates and CAT simulation studies. For the equivalence study, the research group consisted of 81 students (47% female) who participated in both the paper-pencil and live CAT applications. The paper-pencil version of the vocational interest inventory consists of 17 factors and 164 items. When the EAP estimation method and setting SE &lt; .50 as the termination criterion, better performance was obtained compared with other CAT designs. The Item selection did not help to reduce test duration or increase measurement accuracy. As a result, it was found that an area of interest can be assessed with four items. The results of the live CAT application showed that the estimates of CAT were strongly positively correlated with its paper-pencil version. In addition, the live CAT application increased applicability compared to the fixed-length test version by reducing test length by 50% and time by 77%. This study shows that the polytomous IRT-based CAT is applicable and efficient for measuring psychological traits.

Psychometric Evaluation of Glaucoma Quality of Life Item Banks (GlauCAT) and Initial Assessment Using Computerized Adaptive Testing.

PurposeTo evaluate the psychometric properties of glaucoma-specific quality of life (QoL) item banks (GlauCAT) and assess their performance using computerized adaptive testing (CAT) simulations.MethodsIn this cross-sectional study, 293 participants with glaucoma (mean age ± SD, 70.7 ± 13.2 years; 45% female) answered 342 items in 12 QoL item banks (IBs): Activity Limitation (AL); Driving (DV); Convenience (CV); Economic (EC); Emotional (EM); General Symptoms (GS); Health Concerns (HC); Lighting (LT); Mobility (MB); Ocular Surface Symptoms (OS); Social (SC); and Visual Symptoms (VS). These IBs were assessed using Rasch analysis, and CAT simulations with 1000 simulated respondents were utilized to determine the average number of items to be administered to achieve moderate and high precision levels.ResultsThe AL, DV, EM, HC, LT, MB, EC, OS, SC, and VS IBs required relatively minor amendments to achieve satisfactory psychometric fit. To resolve multidimensionality, we split CV into Treatment Convenience (TCV) and General Convenience (GCV). Due to poor measurement precision, the GS IB was not pursued further. This resulted in 12 total IBs. In CAT simulations, an average of 3.7 and 7.3 items per IB were required to attain measurement at moderate and high precision, respectively.ConclusionsFollowing rigorous psychometric assessment, we developed 12 valid glaucoma-specific QoL domains that can obtain highly precise person measure estimates using a small number of items.Translational RelevanceGlauCAT will enable researchers and clinicians to quickly and comprehensively assess the impact of glaucoma and its associated interventions across a range of QoL domains.

Multidimensional Computerized Adaptive Testing Simulations in R

Computerized Adaptive Testing (CAT) is a beneficial test technique that decreases the number of items that need to be administered by taking items in accordance with individuals' own ability levels. After the CAT applications were constructed based on the unidimensional Item Response Theory (IRT), Multidimensional CAT (MCAT) applications have gained momentum with the improvement of multidimensional IRT (MIRT) models in recent years. Researchers often benefit from simulation studies in order to design the final adaptive testing application and to test the effectiveness of adaptive testing applications they developed with different methods. Recently, R has become one of the most widely used programming languages in Monte Carlo Simulation studies since it is a free and open-source software. The aims of this study are to present the MCAT simulation process step by step in the R environment, to examine the effects of the conditions that researchers can handle during the simulation process according to two different dimensional models, and to examine the effect of treating multidimensional structures as unidimensional structures on simulation results. In this direction, datasets generated in accordance with within-item dimensionality and between-item dimensionality models, MCAT simulation studies were constructed with different customizations, and MCAT simulation results were compared with unidimensional CAT simulation results. All commands required for each simulation example were explained and results were shared for each condition.

Development of Computerized Adaptive Testing for Emotion Regulation.

Emotion regulation (ER) plays a vital role in individuals’ well-being and successful functioning. In this study, we attempted to develop a computerized adaptive testing (CAT) to efficiently evaluate ER, namely the CAT-ER. The initial CAT-ER item bank comprised 154 items from six commonly used ER scales, which were completed by 887 participants recruited in China. We conducted unidimensionality testing, item response theory (IRT) model comparison and selection, and IRT item analysis including local independence, item fit, differential item functioning, and item discrimination. Sixty-three items with good psychometric properties were retained in the final CAT-ER. Then, two CAT simulation studies were implemented to assess the CAT-ER, which revealed that the CAT-ER developed in this study performed reasonably well, considering that it greatly lessened the test items and time without losing measurement accuracy.

Psychometric Properties of the Pediatric Patient-Reported Outcomes Measurement Information System Item Banks in a Dutch Clinical Sample of Children With Juvenile Idiopathic Arthritis.

ObjectiveTo assess the psychometric properties of 8 pediatric Patient‐Reported Outcomes Measurement Information System (PROMIS) item banks in a clinical sample of children with juvenile idiopathic arthritis (JIA).MethodsA total of 154 Dutch children (mean ± SD age 14.4 ± 3.0 years; range 8–18 years) with JIA completed 8 pediatric version 1.0 PROMIS item banks (anger, anxiety, depressive symptoms, fatigue, pain interference, peer relationships, physical function mobility, physical function upper extremity) twice and the Pediatric Quality of Life Inventory (PedsQL) and the Childhood Health Assessment Questionnaire (C‐HAQ) once. Structural validity of the item banks was assessed by fitting a graded response model (GRM) and inspecting GRM fit (comparative fit index [CFI], Tucker‐Lewis index [TLI], and root mean square error of approximation [RMSEA]) and item fit (S‐X2 statistic). Convergent validity (with PedsQL/C‐HAQ subdomains) and discriminative validity (active/inactive disease) were assessed. Reliability of the item banks, short forms, and computerized adaptive testing (CAT) was expressed as the SE of theta (SE[θ]). Test–retest reliability was assessed using intraclass correlation coefficients (ICCs) and smallest detectable change.ResultsAll item banks had sufficient overall GRM fit (CFI >0.95, TLI >0.95, RMSEA <0.08) and no item misfit (all S‐X2 P > 0.001). High correlations (>0.70) were found between most PROMIS T scores and hypothesized PedsQL/C‐HAQ (sub)domains. Mobility, pain interference, and upper extremity item banks were able to discriminate between patients with active and inactive disease. Regarding reliability, PROMIS item banks outperformed legacy instruments. Post hoc CAT simulations outperformed short forms. Test–retest reliability was strong (ICC >0.70) for all full‐length item banks and short forms, except for the peer relationships item bank.ConclusionThe pediatric PROMIS item banks displayed sufficient psychometric properties for Dutch children with JIA. PROMIS item banks are ready for use in clinical research and practice for children with JIA.

The physical activity parenting practices (PAPP) item Bank: a psychometrically validated tool for improving the measurement of physical activity parenting practices of parents of 5\u201312-year-old children

BackgroundMany tools have been developed to measure physical activity parenting practices (PAPP). Currently, there is little standardization on how PAPP constructs are operationalized for 5–12 year-old children. Given this lack of consistency our team have started the process of standardizing the measurement of PAPP by developing an item bank which was conceptually informed by 24 experts from 6 countries.PurposeThe purpose of this paper is to present the psychometric properties of the PAPP item bank using the expert-informed PAPP conceptual framework.MethodsA sample (N = 626) of Canadian parents completed the PAPP item bank (100 items measuring 12 constructs). Confirmatory Factor Analyses (CFA), confirmatory bi-factor item analyses, and Item Response Modeling (IRM) were used to assess the structural validity of scores derived from the PAPP item bank. Differential Item Functioning (DIF) and Differential Response Functioning (DRF) were used to determine whether the PAPP items are invariant by parent sex, ethnicity of parent, and household income. Finally, Computerized Adaptive Testing (CAT) simulations were used to determine the efficiency of the item bank – this involved ascertaining whether each construct can be assessed with fewer items.ResultsThe PAPP expert-informed conceptual framework was mainly supported by the CFA analyses. Notable changes included: a) collapsing smaller constructs into one general construct (modeling, co-participation, and monitoring constructs were collapsed into a construct assessing nondirective support); or b) splitting a construct into two smaller constructs (restrict for safety reason construct was split into indoor physical activity restriction and allowance for unsupervised outside physical activity). While the CFA analyses supported the structural validity of 11 constructs, the bi-factor item analyses and IRM analyses supported collapsing correlated constructs into more general constructs. These analyses further reduced the number of constructs measured by the PAPP item bank to nine constructs (65 items – reliability ranging from .79 to .94). As seven of the PAPP constructs had reliability greater than .80, CAT simulations further reduced the number of items to 31 items.ConclusionOverall, the PAPP item bank has excellent psychometric properties and provides an efficient way to assess PAPP.

Development of a Computerized Adaptive Testing System for Assessing Social Knowledge in People With Schizophrenia.

A psychometrically sound measure of social knowledge (SK) is necessary to assess people with schizophrenia because they tend to have moderate to severe deficits in SK. To develop a computerized adaptive test (CAT) for assessing SK in people with schizophrenia. Two phases, consisting of (1) development and validation of an SK item bank and (2) determination of the best stopping rules for the CAT. Two psychiatric hospitals. Two hundred thirty-six people diagnosed with schizophrenia through convenience sampling. Computerized Adaptive Test-Social Knowledge (CAT-SK). The SK items were examined using Rasch analysis. A CAT simulation was performed to determine the best set of stopping rules for achieving high reliability and efficiency. After unsuitable items were removed, 71 items remained with acceptable model fit (infit and outfit mean square <1.4) and no gender bias. Two suboptimal alternative sets of rules were identified. The most efficient set used 21 items to achieve acceptable Rasch reliability (.81). The most reliable set used 40 items to achieve satisfactory Rasch reliability (.88). High correlations (r > .93) between CAT-SK scores and scores on the SK item bank support the concurrent validity of the CAT-SK. The CAT-SK appears to be a valid assessment that can provide reliable or efficient measures of SK. If high reliability is needed, examiners can adopt the most reliable set of 40 items. If efficiency is the primary concern, they can adopt the most efficient set of 21 items. The CAT-SK is a valid measure of SK with flexibility to meet examiners' needs.

Ability estimation in computerized adaptive test using Mamdani Fuzzy Inference System

Assessment is an activity to find out the learning outcomes of a course. Conventionally, assessment is done using a pencil and paper test. Along with the development of information and communication technology, evaluation can be done computerized, known as Computer Based Test (CBT). The Computerized Adaptive Test (CAT) is one form of CBT where the items given are chosen based on the students’ abilities. This research aims to design a system that can estimate the ability of students based on the parameters of the questions and answers given. The estimation method uses the Mamdani Fuzzy Inference System (MFIS). The input MFIS is a level of difficulty and discrimination of the questions, the probability of students being able to answer correctly, and the student’s answer, while the output is an ability estimated. Based on this fuzzy system output, the next item questions will be determined according to the ability of the students. 24 IF-THEN rules are used for fuzzy systems. CAT simulations are carried out for Linear Algebra Course with six topics, namely vector, matrices concepts, matrices operation, determinant, inverse, and matrices applications. The type of question given is multiple choice. Giving items will be stopped if the value of the estimated ability of the students has not changed. From the simulations carried out, for each topic, the ability of the student can be acquired with the number of questions as many as six questions. So that the CAT system can minimize the time of the exam, reduce the subjectivity of the assessment and can arrange for each student to get the questions according to his abilities.

A new approach to assessing shyness of college students using computerized adaptive testing: CAT-Shyness

Assessing shy symptoms via computerized adaptive testing (CAT) provides greater measurement precision coupled with a lower test burden compared to conventional tests. The computerized adaptive test for shyness (CAT-Shyness) was developed based on a large sample of 1400 participants from China. Item bank development included the investigation of unidimensionality, local independence, and exploration of differential item functioning (DIF). CAT simulations based on the real data were carried out to investigate the reliability, validity, and predicted utility (sensitivity and specificity) of the CAT-Shyness. The CAT-Shyness item bank was successfully built and proved to have excellent psychometric properties: high content validity, unidimensionality, local independence, and no DIF. The CAT simulations needed 14 items to achieve a high measurement precision with a reliability of .9. Moreover, the results revealed that the proposed CAT-Shyness had acceptable and reasonable marginal reliability, criterion-related validity, and sensitivity and specificity. It not only had acceptable psychometric properties, but also had a shorter but efficient assessment of shyness, which can save significant test time and reduce the test burden for individuals with less information loss.

Computerized adaptive testing and short form development for child and adolescent oral health patient-reported outcomes measurement.

ObjectivesTo develop computerized adaptive testing (CAT) and short forms of self‐report oral health measures that are predictive of both the children's oral health status index (COHSI) and the children's oral health referral recommendation (COHRR) scales, for children and adolescents, ages 8–17.Material and methodsUsing final item calibration parameters (discrimination and difficulty parameters) from the item response theory analysis, we performed post hoc CAT simulation. Items most frequently administered in the simulation were incorporated for possible inclusion in final oral health assessment toolkits, to select the best performing eight items for COHSI and COHRR.ResultsTwo previously identified unidimensional sets of self‐report items consisting of 19 items for the COHSI and 22 items for the COHRR were administered through CAT resulting in eight‐item short forms for both the COHSI and COHRR. Correlations between the simulated CAT scores and the full item bank representing the latent trait are r = .94 for COHSI and r = .96 for COHRR, respectively, which demonstrated high reliability of the CAT and short form.ConclusionsUsing established rigorous measurement development standards, the CAT and corresponding eight‐item short form items for COHSI and COHRR were developed to assess the oral health status of children and adolescents, ages 8–17. These measures demonstrated good psychometric properties and can have clinical utility in oral health screening and evaluation and clinical referral recommendations.

Optimizing measurement of vision-related quality of life: a computerized adaptive test for the impact of vision impairment questionnaire (IVI-CAT).

To compare the results from a simulated computerized adaptive test (CAT) for the 28-item Impact of Vision Impairment (IVI) questionnaireand the original paper-pencil version in terms of efficiency (main outcome), defined as percentage item reduction. Using paper-pencil IVI data from 832 participants across the spectrum of vision impairment, item calibrations of the 28-item IVI instrument and its associated 20-item vision-specific functioning (VSF) and 8-item emotional well-being (EWB) subscales were generated with Rasch analysis. Based on these calibrations, CAT simulations were conducted on 1000 cases, with 'high' and 'moderate' precision stopping rules (standard error of measurement [SEM] 0.387 and 0.521, respectively). We examined the average number of items needed to satisfy the stopping rules and the corresponding percentage item reduction, level of agreement between person measures estimated from the full IVI item bank and from the CAT simulations, and item exposure rates (IER). For the overall IVI-CAT, 5 or 9.7 items were required, on average, to obtain moderate or high precision estimates of vision-related quality of life, corresponding to 82.1 and 65.4% item reductions compared to the paper-pencil IVI. Agreement was high between the person measures generated from the full IVI item bank and the IVI-CAT for both the high precision simulation (mean bias, - 0.004 logits; 95% LOA - 0.594 to 0.587) and moderate precision simulation (mean bias, 0.014 logits; 95% LOA - 0.828 to 0.855). The IER for the IVI-CAT in the moderate precision simulation was skewed, with six EWB items used > 40% of the time. Compared to the paper-pencil IVI instrument, the IVI-CATs required fewer items without loss of measurement precision, making them potentially attractive outcome instruments for implementation into clinical trials, healthcare, and research. Final versions of the IVI-CATs are available.

Development and Psychometric Assessment of Novel Item Banks for Hereditary Retinal Diseases.

This study develops psychometrically valid item banks across 10 areas of quality of life (QoL) specific to people with hereditary retinal diseases, which will enable clinicians and researchers to explore the impact of hereditary retinal diseases across all aspects of QoL. The purpose of this study was to assess the psychometric properties of hereditary retinal disease QoL item banks using Rasch analysis and demonstrate the effectiveness of a computerized adaptive testing (CAT) system in obtaining precise measurement of QoL using only a few items. The hereditary retinal disease item banks were answered by 233 participants (median age, 58 years; range, 18 to 94 years; female participants, 59%). The hereditary retinal disease item banks cover 10 QoL domains: activity limitation, mobility, emotional, social, convenience, economic, health concerns, visual symptoms, ocular comfort symptoms, and general symptoms. Rasch analysis assessed the psychometric properties of the 10 item banks and provided item calibrations for the development of CAT. Computerized adaptive testing simulations were performed to calculate the average number of items required to gain precise measurement of each QoL domain. The convenience, economic, visual symptoms, and the social domains formed unidimensional scales. However, the activity limitation and health concerns domains demonstrated multidimensionality and required major modifications to resolve this, which resulted in four new QoL domains, namely, reading, driving, lighting, and concerns about the disease progression. In total, 10 item banks underwent CAT simulation testing, which indicated that 8 to 12 items were required to gain precise measurement of each QoL domain. We have developed 10 psychometrically valid item banks to measure the QoL domains relevant to people with hereditary retinal diseases. On average, only 5 and 10 items were required to gain measurement at moderate and high precision, respectively.