Evaluation of a self-report measure of low-vision functional ability

Persistent Link:
http://hdl.handle.net/10150/280406
Title:
Evaluation of a self-report measure of low-vision functional ability
Author:
Cunningham, Victoria Lynn
Issue Date:
2003
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
The majority of data used in outcome research has until recently been based primarily on treatment provider observations of the patient. Estimating the effect of rehabilitation treatment on functional ability is increasingly relying on patient self-report ratings. Controlling for measurement bias associated with the subjective nature of this type of data was handled by putting self-report and clinician responses to items on an 11-item functional ability instrument into the same metric using a Rasch model, allowing for an accurate picture of whether and how their perceptions differ. For this study, the traditionally clinician-rated instrument was modified to accommodate self-report ratings. The questionnaire was verbally administered during individualized discharge interviews to 112 visually-impaired geriatric veterans whose responses were then paired with clinician ratings. Clinician ratings replicate previous findings which provided a stable foundation against which the self-report ratings were compared. Fit statistics for self-report ratings demonstrate unidimensionality of the assumed functional ability construct. Construct validity, or to what extent clinicians and patients agree on what it is that is being measured (i.e., functional ability), was supported by a moderate correlation between person ability estimates. More informative, however, was the agreement on item difficulty estimates. While six of the 11 items had roughly the same difficulty estimates across the two rating samples, 5 others lacked agreement. Two possible reasons for this incongruity are (1) patient expectations about what they should be able to do by the end of rehabilitation are not realized and (2) exemplars used in eliciting self-report ratings are not as specific as those used by clinicians. The single-factor structure was also analyzed by a confirmatory factor analysis. Although the model did not meet conventional criteria of .95 for the CFI, it was the most parsimonious solution for both sets of ratings as demonstrated by a multisample analysis. These analyses indicated that self-perceived functional ability ratings may be used in place of clinician ratings on the majority of the FAST items. Until the remaining items are modified, at this point, self-report ratings may, at best, supplement, but not be used in place of, clinician ratings.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Psychology, Psychometrics.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Psychology
Degree Grantor:
University of Arizona
Advisor:
Sechrest, Lee

Full metadata record

DC FieldValue Language
dc.language.isoen_USen_US
dc.titleEvaluation of a self-report measure of low-vision functional abilityen_US
dc.creatorCunningham, Victoria Lynnen_US
dc.contributor.authorCunningham, Victoria Lynnen_US
dc.date.issued2003en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractThe majority of data used in outcome research has until recently been based primarily on treatment provider observations of the patient. Estimating the effect of rehabilitation treatment on functional ability is increasingly relying on patient self-report ratings. Controlling for measurement bias associated with the subjective nature of this type of data was handled by putting self-report and clinician responses to items on an 11-item functional ability instrument into the same metric using a Rasch model, allowing for an accurate picture of whether and how their perceptions differ. For this study, the traditionally clinician-rated instrument was modified to accommodate self-report ratings. The questionnaire was verbally administered during individualized discharge interviews to 112 visually-impaired geriatric veterans whose responses were then paired with clinician ratings. Clinician ratings replicate previous findings which provided a stable foundation against which the self-report ratings were compared. Fit statistics for self-report ratings demonstrate unidimensionality of the assumed functional ability construct. Construct validity, or to what extent clinicians and patients agree on what it is that is being measured (i.e., functional ability), was supported by a moderate correlation between person ability estimates. More informative, however, was the agreement on item difficulty estimates. While six of the 11 items had roughly the same difficulty estimates across the two rating samples, 5 others lacked agreement. Two possible reasons for this incongruity are (1) patient expectations about what they should be able to do by the end of rehabilitation are not realized and (2) exemplars used in eliciting self-report ratings are not as specific as those used by clinicians. The single-factor structure was also analyzed by a confirmatory factor analysis. Although the model did not meet conventional criteria of .95 for the CFI, it was the most parsimonious solution for both sets of ratings as demonstrated by a multisample analysis. These analyses indicated that self-perceived functional ability ratings may be used in place of clinician ratings on the majority of the FAST items. Until the remaining items are modified, at this point, self-report ratings may, at best, supplement, but not be used in place of, clinician ratings.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectPsychology, Psychometrics.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplinePsychologyen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorSechrest, Leeen_US
dc.identifier.proquest3108896en_US
dc.identifier.bibrecord.b44825092en_US
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