A New Method of Assessing Ability to Perform Activities of Daily Living: Design, Methods and Baseline Data

Abstract

Purpose:: To describe the study protocol and the baseline characteristics of the subjects. This study seeks to determine the relationship of a third-generation performance-based measure of visual function to clinical and subjective measures in glaucoma patients.

Methods:: Cross-sectional study from March 2006 to December 2006 of 194 glaucoma patients exhibiting the full range of visual loss caused by glaucoma. The study was performed at the Wills Eye Hospital. Patients ranged in age from 15-95. Exclusion criteria were inability to understand and respond to spoken English, low vision training, and presence of significant neurological, motor or other problems that may have prevented the patient from completing the study. After informed consent, patients were evaluated using a third-generation, novel, performance-based measure, the Assessment of Disability Related to Vision (ADREV) which comprises nine tasks which simulate various activities of daily living; these include: 1) putting a stick into 7 holes of different sizes, 2) entering numbers into different sized calculators, 3) finding large and small objects spread around a room, 4) detecting motion, 5) matching socks, 6) reading print under dull and bright light, 7) following a prescribed walking course, 8) recognizing signs at a distance and 9) recognizing facial expressions. All patients also completed a battery of standard clinical tests of visual function including visual acuity, bilateral visual fields test (Humphrey), binocular visual field test (Estermann), contrast sensitivity and stereopsis, as well as the National Eye Institute’s Visual Functioning Questionnaire (NEI-VFQ-25). Main Outcome Measures are the scores on the subtests (range 0-7 on each subtest) and the total scores of ADREV (range 0-63) and NEI-VFQ-25 (range 0-100).

Results:: Mean age was 67.1. 50.5 % were females. 55.2 % were of European extraction. 71.6 % had primary open-angle glaucoma. A strength of this study was the inclusion of the full range of clinical severities. For example, with regards to the mean defect as determined by Humphrey visual field testing in the worse eye, the mean was -16 dB with a range from +1 to -40 dB.

Conclusions:: This study should show 1) how much and what types of disability are caused by glaucoma, 2) how those difficulties in performing the activities of daily living relate to standard clinical tests and 3) how they relate to the types and amount of change in quality of life. We wish to share the methodology with others.

Keywords: clinical research methodology • quality of life