Abstract
Purpose: :
To measure differences between doctors (OD/MD) (DR), occupational therapists (OT), and vision rehabilitation therapists (RT) in estimates of rehabilitation potential of low vision patients.
Methods: :
One hundred vision rehabilitation service providers representing three different professions (DR, OT, RT) reviewed and rated rehabilitation potential of 10 cases online. Using a 5-category ordinal scale, clinicians estimated the probability of successful rehabilitation outcomes for each case. Rehabilitation potential of each case was estimated on an interval scale using Rasch analysis. Applying conventional terminology of Rasch analysis, cases were treated as "items" and clinicians as "persons". Estimated item measures defined the rehabilitation potential of each case and estimated person measures defined each clinician’s overall bias toward optimistic or pessimistic judgments of patient outcomes. Chi-square-like item and person measure fit statistics were used to judge validity of the estimated measures.
Results: :
Estimated rehabilitation potential of 10 cases ranged from-2.95 to 1.6 logits with a standard deviation of 1.28 logits. Fit statistics indicated all cases agreed with expectations of the measurement model and verified the validity and unidimensionality of the rehabilitation potential measure. There was no differential item functioning based on category of clinician. Fit statistics indicated all clinician responses agreed with the expectations of the measurement model, verifying unidimensionality and validity of person measures. As illustrated in figure, ANOVA showed a significant difference in bias between professions. RTs had the highest level of bias and DRs had the lowest.
Conclusions: :
The present study finds significant differences between doctors, occupational therapists, and vision rehabilitation therapists in their estimates of rehabilitation potential of low vision patients. Of the three groups, doctors who provide vision rehabilitation services are the most pessimistic about patient outcomes and vision rehabilitation therapists are the most optimistic.
Keywords: low vision • clinical (human) or epidemiologic studies: outcomes/complications • clinical (human) or epidemiologic studies: biostatistics/epidemiology methodology