Article

Rasch analysis of the Ocular Surface Disease Index (OSDI).

The Ohio State University College of Optometry, Columbus, Ohio, USA.
Investigative ophthalmology & visual science (Impact Factor: 3.43). 09/2011; 52(12):8630-5. DOI: 10.1167/iovs.11-8027
Source: PubMed

ABSTRACT The Ocular Surface Disease Index (OSDI) is a 12-item scale for the assessment of symptoms related to dry eye disease and their effect on vision. Its reliability and validity have been investigated within the classical test theory framework and, more recently, using Rasch analysis. The purpose of the present analysis was to more completely investigate the functioning of its response category structure, the validity of its three subscales, and the unidimensionality of the latent construct it is intended to assess.
Responses to the OSDI from 172 females participating in the Dry Eye in Postmenopause (DEiM) study who had previously been diagnosed with dry eye or reported significant ocular irritation and dryness were analyzed. Response category structure and item fit statistics were evaluated for assessment of model fit. Person separation statistics were used to examine the validity of the subscales. Unidimensionality was assessed by principal component analysis (PCA) of model residuals.
The recommended five-category response structure resulted in disordered response thresholds. A four-category structure resulted in ordered thresholds. Item infit statistics were acceptable for all 12 items. Person separation with this category structure was adequate, with a person separation index of 2.16. None of the three subscales demonstrated adequate person separation. PCA showed one other significant factor onto which the three environmental items loaded significantly.
All items demonstrated acceptable fit to the model after collapsing categories to order the response thresholds. The original subscales did not prove valid, and there is some evidence of multidimensionality and poor targeting.

0 Bookmarks
 · 
225 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Rationale Allergic conjunctivitis (AC) is commonly under-diagnosed and undertreated as well as dry eye syndromes (DES). The TOSS scores is used to indicate AC severity and the Ocular Surface Disease Index (OSDI) is a validated questionnaire for DES severity. The utility of the scores of a standard dry eye questionnaire with TOSS scores was compared for consecutive patients seen in an optometric practice. Methods 105 patients were administered both the TOSS and Ocular Surface Disease Index (OSDI) questionnaires. The OSDI is a 12-question questionnaire scored 0 to 100. TOSS questionnaire was scored as a percentage from 0 to 100 and covers four domains: itch, redness, tearing and swelling. Results For 65 females and 40 males, average age 41.2 years old, the overall mean score for OSDI was 22.64 SD 20.69, the overall mean for TOSS was 23.33 SD 24.13. Overall, there was a moderate correlation between the TOSS and OSDI (Pearson 0.544;p<. 001) For males, the correlation was strong (0.709, p<.001), for females the correlation was weak to moderate (Pearson 0.390, p<.001) Conclusions Although both questionnaires have entirely different domains, the correlation was moderate overall and strong for males. The overall mean scores were also very similar.
    The Journal of allergy and clinical immunology 02/2013; 131(2):AB189. · 12.05 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this article was to systematically review all the available ophthalmic patient-reported outcome (PRO) instruments (questionnaires) that demonstrated interval measurement properties to identify the instruments with the highest psychometric quality for use in different eye diseases and conditions. An extensive literature review was carried out to identify all existing ophthalmic PRO instruments. Instruments were then excluded if they did not have demonstrable interval measurement properties; the remaining instruments were reviewed. The quality of the following psychometric properties was assessed: content development (initial item development process), performance of the response scale, dimensionality (whether the instrument measures a single construct), measurement precision, validity (convergent, concurrent, discriminant, and known groups), reliability (test-retest), targeting (whether the items are appropriate [e.g., difficulty level] for the population), differential item functioning (whether subgroups of people respond differently to an item), and responsiveness. The search identified 48 PRO instruments that demonstrated interval measurement properties, and these were relevant to nine applications: glaucoma, dry eye, refractive errors, cataract, amblyopia and strabismus, macular diseases, adult low vision, children low vision, and others. These instruments were evaluated against the psychometric property quality criteria and were rated for quality based on the number of criteria met. This review provides a descriptive catalog of ophthalmic PRO instruments to inform researchers and clinicians on the choice of the highest-quality PRO instrument suitable for their purpose.
    Optometry and vision science: official publication of the American Academy of Optometry 07/2013; · 1.53 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To evaluate the effect of diquafosol tetrasodium (DQS) for the treatment of persistent dry eye after laser in situ keratomileusis (LASIK).
    Cornea 05/2014; · 1.75 Impact Factor

Full-text

Download
2 Downloads
Available from