Fig. 3From: Reliability of health-related quality-of-life assessments made by older adults and significant others for health states of increasing cognitive impairmentBland-Altman plots, combining ratings over the three time points (n = 608). The solid horizontal line is drawn at the mean of the differences in ratings (\( \overline{d} \)) within dyads, thus providing an estimate of the amount of overall bias. The two dashed lines are 95% limits of agreement defined as \( \overline{d} \) ± 1.96 s d where s d is the standard deviation of the differences corrected for clustering [29]. These lines delimit the range within which 95% of the differences lie. Scores below the zero difference line indicate that the proxy provided a higher rating than the older adult (i.e., poorer health-related quality of life), and conversely for scores above that lineBack to article page