Abstract
Purpose:
Compare measures of low vision rehabilitation outcomes estimated from patient-report, therapist-report, and performance of timed independent activities of daily living (TIADL) tasks.
Methods:
Forty home-health patients with low vision were administered the Activity Inventory (AI) by telephone interview; performed 17 standardized TIADL tasks in their customary manner in their home; and had their patient-identified activity goals from the AI rated by the therapist using the Functional Independence Measure (FIM) scale. These tests were conducted on all patients both before and after provision of LVR services in each patient’s home by the same therapist. Rasch analysis was used to estimate patients’ functional abilities from each of the three sets of test data. Outcomes estimated from TIADL results were compared to outcomes estimated from patient difficulty ratings of AI tasks customarily performed indoors. Outcomes estimated from FIM ratings of patient-identified activity goals were compared to outcomes estimated from patient difficulty ratings of the same AI goals.
Results:
At pre-LVR baseline, correlations were 0.57 between functional ability measures estimated from patient ratings of AI Goals and measures estimated from FIM ratings of the same AI Goals by the therapist. Correlations were 0.52 between measures estimated from patient ratings of indoor AI tasks and measures estimated from patient performance of TIADL tasks. After LVR the correlations were 0.43 for patient-reported vs therapist-reported measures and 0.25 for patient-reported vs performance-based measures. LVR effect sizes for the sample of 40 patients was 0.65 for performance-based measures and 0.85 for the corresponding patient-reported measures. LVR effect sizes were 2.74 for therapist-reported measures and 0.49 for the corresponding patient-reported measures.
Conclusions:
There is strong agreement between functional ability measures estimated from patient difficulty ratings of AI goals important to them and measures estimated from therapist FIM ratings of the same goals. Similar strong agreement is seen between functional ability measures estimated from TIADL task performance and measures estimated from patient's difficulty ratings of AI IADL tasks. However, there is disagreement between measures in the magnitude of the effect of rehabilitation.