S. Dahlin-ivanoff et al., Development of an ADL instrument targeting elderly persons with age-related macular degeneration, DISABIL REH, 23(2), 2001, pp. 69-79
Background : In order to estimate the needs of early intervention in a heal
th education program, an ADL instrument measuring feelings of (in) security
was needed. The instrument was intended to detect early signs of decline a
nd to evaluate ADL performance among persons with AMD. An evaluative instru
ment must have a high level of responsiveness, which is the ability to dete
ct true changes over time but must also show a high level of intra-individu
al agreement in a test-retest assessment.
Purpose : The purpose of this study was to develop an ADL instrument for ev
aluative purposes and to establish the reliability and the responsiveness o
f the instrument.
Method: The target group comprised all persons referred by an ophthalmologi
st for low vision rehabilitation, 65 years and older, living at home, with
aged-related macular degeneration as the primary diagnosis and with distanc
e visual acuity of the better eye with best correction not lower than 0.1.
A nonparametric statistical method that is developed for paired ordered par
ametrical data was applied in order to measure the systematic and occasiona
l intra-rater disagreement separately and to measure the responsiveness.
Conclusion : The test-retest study showed that the ADL-instrument had a hig
h level of test-retest stability, which is a condition for responsiveness.
The instrument was found to be responsive. It could therefore detect true l
ongitudinal changes and be used for evaluative purposes targeting elderly w
ith AMD.