Dataset Information

Evaluation of the Adult Strabismus-20 (AS-20) questionnaire using Rasch analysis.

ABSTRACT: To further refine the Adult Strabismus 20 (AS-20) health-related quality of life (HRQOL) questionnaire using Rasch analysis.Rasch analysis was performed independently on the original AS-20 using the following steps: dimensionality, response ordering, local dependence, infit and outfit analyses, differential item functioning, subject targeting, and confirmatory dimensionality.Two subscales were present in each of the original AS-20 subscales, for a total of 4 subscales, which were labeled "self-perception," "interaction," "reading function," and "general function." Response ordering was appropriate for 3 of the subscales but required reduction to 4 response options for the fourth subscale. No notable local dependence was found for any subscale. As a result of fit analysis, 2 items were removed, 1 each from 2 subscales. No significant differential item functioning was seen for sex or age. The resulting 5-item self-perception subscale and 4-item reading function subscale are reliable and target the adult strabismus patient cohort appropriately. The resulting 5-item interaction subscale and 4-item general function subscale have less than optimal reliability.The AS-20 benefits from reduction to 4 subscales (self-perception, interaction, reading function, and general function) and reducing the response options in the general function subscale from 5 to 4 options. The refined AS-20 may prove to be even more responsive to HRQOL changes in adult strabismus following treatment or changes over time.

SUBMITTER: Leske DA

PROVIDER: S-EPMC4686183 | biostudies-literature | 2012 May

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Evaluation of the Adult Strabismus-20 (AS-20) questionnaire using Rasch analysis.

Leske David A DA Hatt Sarah R SR Liebermann Laura L Holmes Jonathan M JM

Investigative ophthalmology & visual science 20120504 6

<h4>Purpose</h4>To further refine the Adult Strabismus 20 (AS-20) health-related quality of life (HRQOL) questionnaire using Rasch analysis.<h4>Methods</h4>Rasch analysis was performed independently on the original AS-20 using the following steps: dimensionality, response ordering, local dependence, infit and outfit analyses, differential item functioning, subject targeting, and confirmatory dimensionality.<h4>Results</h4>Two subscales were present in each of the original AS-20 subscales, for a ...[more]

PMID: 22447864

Similar Datasets

Project description:PurposeTo evaluate the psychometric properties of the Adult Strabismus-20 (AS-20)- a health-related quality of life (HRQoL) questionnaire in adults with strabismus, and if flawed, to revise the AS-20 and its subscales creating valid measurement scales.Methods584 adults (meanage, 27.5 years) with strabismus were recruited from an outpatient clinic at a South Indian tertiary eye care centre and were administered the AS-20 questionnaire.The AS-20 was translated and back translated into two Indian languages. The AS-20 and its two 10-item subscales - 'psychosocial' and 'function'were assessed separately for fit to the Rasch model, including an assessment of the rating scale, unidimensionality (by principal components analysis), measurement precision by person separation reliability, PSR, targeting, and differential item functioning (DIF; notable > 1.0 logits).ResultsResponse categories were not used as intended, thereby, required re-organization and reducing their number from 5 to 3. The AS-20 had adequate measurement precision (PSR = 0.87) but lacked unidimensionality; however, deletion of the six multi-dimensionality causing items and an additional three misfitting items resulted in 11-item unidimensional questionnaire (AS-11). Two items failed to satisfy the model expectations in the 'psychosocial' subscale and were deleted - resulting in an 8-item unidimensional scale with adequate PSR (0.81) and targeting (0.23 logits). One item misfit in the 'function' subscale and was deleted-resulting in a 9 item Rasch-revised unidimensional subscale with acceptable PSR (0.80) and targeting (0.97 logits).None of the items displayed notable DIF by age, gender and level of education.ConclusionsThe AS-11 and its two Rasch-revised subscales - 8-item psychosocial and 9-item function subscale may be more appropriate than the original AS-20 and its two 10-item subscales for use as unidimensional measures of HRQoL in adults with strabismus in India. Further work is required to establish the validity of the revised rating scale.

Project description:Background:The Patient-Rated Wrist Evaluation (PRWE) was developed as a wrist joint specific measure of pain and disability and evidence of sound validity has been accumulated through classical psychometric methods. Rasch analysis (RA) has been endorsed as a newer method for analyzing the clinical measurement properties of self-report outcome measures. The purpose of this study was to evaluate the PRWE using Rasch modeling. Methods:We employed the Rasch model to assess overall fit, response scaling, individual item fit, differential item functioning (DIF), local dependency, unidimensionality and person separation index (PSI). A convenience sample of 382 patients with distal radius fracture was recruited from the hand and upper limb clinic at large academic healthcare organization, London, Ontario, Canada, 6-month post-injury scores of the PRWE was used. RA was conducted on the 3 subscales (pain, specific activities, and usual activities) of the PRWE separately. Results:The pain subscale adequately fit the Rasch model when item 4 "Pain - When it is at its worst" was deleted to eliminate non-uniform DIF by age group, and item 5 "How often do you have pain" was rescored by collapsing into 8 intervals to eliminate disordered thresholds. Uniform DIF for "Use my affected hand to push up from the chair" (by work status) and "Use bathroom tissue with my affected hand" (by injured hand) was addressed by splitting the items for analysis. After background rescoring of 2 items in pain subscale, 2 items in specific activities and 3 items in usual activities, all three subscales of the PRWE were well targeted and had high reliability (PSI?=?0.86). These changes provided a unidimensional, interval-level scaled measure. Conclusion:Like a previous analysis of the Patient-Rated Wrist and Hand Evaluation, this study found the PRWE could be fit to the Rasch model with rescoring of multiple items. However, the modifications required to achieve fit were not the same across studies, our fit statistics also suggested one of the pain items should be deleted. This study adds to the pool of evidence supporting the PRWE, but cannot confidently provide a Rasch-based scoring algorithm.

Project description:ObjectivesEmpowerment is the process through which individuals with hearing-related challenges acquire and use knowledge, skills and strategies, and increase self-efficacy, participation, and control of their hearing health care, hearing solutions, and everyday lives. The aim was to refine and validate the Empowerment Audiology Questionnaire (EmpAQ), a hearing-specific measure of empowerment. This was achieved through (1) refinement via Rasch analysis (study 1), and (2) traditional psychometric analysis of the final survey structure (study 2).DesignIn study 1, 307 adult hearing aid owners completed the initial empowerment measure (33 items) online. To inform an intended item reduction, Rasch analysis was used to assess a range of psychometric properties for individual items. The psychometric properties included analysis of individual items (e.g., response dependency, fit to the polytomous Rasch model, threshold ordering) and the whole EmpAQ (e.g., dimensionality). Item reduction resulted in a 15-item version (EmpAQ-15) and a short-form 5-item version (EmpAQ-5), validated using modern (Rasch), and traditional (Classical Test Theory) psychometric analysis (study 2). In study 2, 178 adult hearing aid owners completed the EmpAQ-15 and EmpAQ-5, alongside 5 questionnaires to measure related constructs. These included two hearing-specific questionnaires (Social Participation Restrictions Questionnaire and Self-Assessment of Communication), two general health-related questionnaires (Patient Activation Measure and World Health Organization Disability Assessment Schedule 2.0), and a general empowerment questionnaire (Health Care Empowerment Questionnaire). Modern (Rasch) and traditional psychometric analysis techniques (internal consistency, construct validity, and criterion validity) were used to assess the psychometric properties of the EmpAQ-15 and EmpAQ-5.ResultsRasch analysis of the initial 33-item measure of empowerment identified 18 items with high response dependency, poor fit to the Rasch model, and threshold disordering, which were removed, resulting in a long-form (EmpAQ-15) hearing-specific measure of empowerment. A short-form (EmpAQ-5) version was developed for use in the clinic setting. Validation of the two EmpAQ measures using Rasch analysis showed good item fit to the Rasch model, appropriate threshold targeting, and the existence of unidimensionality. Traditional psychometric evaluation showed that both questionnaires had high internal consistency and positive correlations with the hearing-specific questionnaires. However, in contrast with our hypotheses, correlations with general health questionnaires were stronger than with hearing-specific questionnaires; all questionnaires were correlated with the EmpAQ and in the direction hypothesized. Taken together, these findings support the construct validity of the EmpAQ-15 and EmpAQ-5.ConclusionsThe EmpAQ-15 and EmpAQ-5 are the first self-report measures to be developed specifically for the measurement of empowerment. The EmpAQ-15 and EmpAQ-5 were found to meet the Rasch model criteria for interval-level measurements. Traditional psychometric evaluation supports the construct validity of both measures. The EmpAQ measures have the potential to be used in both research and clinical practice to evaluate empowerment along the hearing journey. The next stage of this research will be to further validate these measures by assessing their responsiveness, minimal clinically important difference, and clinical interpretability in a clinical population.

Project description:BackgroundClinical teaching evaluations are common in health profession education programs to ensure students are receiving a quality clinical education experience. Questionnaires students use to evaluate their clinical teachers have been developed in professions such as medicine and nursing. The development of a questionnaire that is specifically for the osteopathy on-campus, student-led clinic environment is warranted. Previous work developed the 30-item Osteopathy Clinical Teaching Questionnaire. The current study utilised Rasch analysis to investigate the construct validity of the Osteopathy Clinical Teaching Questionnaire and provide evidence for the validity argument through fit to the Rasch model.MethodsSenior osteopathy students at four institutions in Australia, New Zealand and the United Kingdom rated their clinical teachers using the Osteopathy Clinical Teaching Questionnaire. Three hundred and ninety-nine valid responses were received and the data were evaluated for fit to the Rasch model. Reliability estimations (Cronbach's alpha and McDonald's omega) were also evaluated for the final model.ResultsThe initial analysis demonstrated the data did not fit the Rasch model. Accordingly, modifications to the questionnaire were made including removing items, removing person responses, and rescoring one item. The final model contained 12 items and fit to the Rasch model was adequate. Support for unidimensionality was demonstrated through both the Principal Components Analysis/t-test, and the Cronbach's alpha and McDonald's omega reliability estimates. Analysis of the questionnaire using McDonald's omega hierarchical supported a general factor (quality of clinical teaching in osteopathy).ConclusionThe evidence for unidimensionality and the presence of a general factor support the calculation of a total score for the questionnaire as a sufficient statistic. Further work is now required to investigate the reliability of the 12-item Osteopathy Clinical Teaching Questionnaire to provide evidence for the validity argument.

Dataset Information

Evaluation of the Adult Strabismus-20 (AS-20) questionnaire using Rasch analysis.

Publications

Evaluation of the Adult Strabismus-20 (AS-20) questionnaire using Rasch analysis.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets