Je. Storey et al., A comparison of five clock scoring methods using ROC (receiver operating characteristic) curve analysis, INT J GER P, 16(4), 2001, pp. 394-399
Objective To compare the accuracy of five clock scoring methods for detecti
ng dementia in English-speaking patients.
Design A prospective cohort study.
Setting A general geriatric outpatient clinic in southwest Sydney, Australi
a.
Participants A total of 127 consecutive new referrals to the clinic, of mea
n age 78.2 years.
Measurements The clock drawing test was conducted at the beginning of each
clinic appointment by a blinded observer. Each patient was then assessed by
a geriatrician, who collected demographic data, administered the modified
Barthel index, the geriatric depression scale, and the Folstein Mini-Mental
State Examination, and categorised each patient as demented or not demente
d, according to DSM-4 criteria. Each clock was scored according to the meth
ods of Mendez, Shulman, Sunderland, Watson and Wolf-Klein, and evaluated fo
r reliability, and predictive accuracy, using receiver operating characteri
stic (ROC) curve analysis.
Results The area under the ROC curve was largest for the Shulman (0.79, 95%
CI 0.70-0.85) and Mendez (0.78, 95% CI 0.70-0.85) methods. Both predicted
dementia more accurately than the Sunderland (area = 0.71) and Watson (area
= 0.65) methods (p < 0.05). The inter-rater (0.81-0.93) and intra-rater (0
.87-0.96) correlation coefficients were high for all five methods.
Conclusions While substantial differences among the clock scoring methods w
ere evident in our sample, the accuracy of each was modest at best. Unless
further studies in relevant settings suggest otherwise, we caution on the u
se of clock drawing alone to screen for dementia. Copyright (C) 2001 John W
iley & Sons, Ltd.