Background: The Cambridge Cognitive Examination (CAMCOG) is a useful test in screening for Alzheimer's disease (AD). However, the interpretation of CAMCOG cut-off scores is problematic and reference values are needed for different educational strata. Given the importance of earlier diagnoses of mild dementia, new cut-off values are required which take into account patients with low levels of education. This study aims to evaluate whether the CAMCOG can be used as an accurate screening test among AD patients and normal controls with different educational levels.

Methods: Cross-sectional assessment was undertaken of 113 AD and 208 elderly controls with heterogeneous educational levels (group 1: 1–4 years; group 2: 5–8 years; and group 3: ≥ 9 years) from a geriatric clinic. submitted to a thorough diagnostic evaluation for AD including the Cambridge Examination for Mental Disorders of the Elderly (CAMDEX). Controls had no cognitive or mood complaints. Sensitivity (SE) and specificity (SP) for the CAMCOG in each educational group was assessed with receiver-operator-characteristic (ROC) curves.

Results: CAMCOG mean values were lower when education was reduced in both diagnostic groups (controls – group 1: 87; group 2: 91; group 3: 96; AD – group 1: 63; group 2: 62; group 3: 77). Cut-off scores for the three education groups were 79, 80 and 90, respectively. SE and SP varied among the groups (group 1: 88.1% and 83.5%; group 2: 84.6% and 96%; group 3: 70.8% and 90%).

Conclusion: The CAMCOG can be used as a cognitive test for patients with low educational level with good accuracy. Patients with higher education showed lower scores than previously reported.

Background: Although the Clock Drawing Test (CDT) is the second most used test in the world for the screening of dementia, there is still debate over its sensitivity, specificity, application and interpretation in dementia diagnosis. This study has three main aims: to evaluate the sensitivity and specificity of the CDT in a sample composed of older adults with Alzheimer's disease (AD) and normal controls; to compare CDT accuracy to the that of the Mini-mental State Examination (MMSE) and the Cambridge Cognitive Examination (CAMCOG); and to test whether the association of the MMSE with the CDT leads to higher or comparable accuracy as that reported for the CAMCOG.

Methods: Cross-sectional assessment was carried out for 121 AD and 99 elderly controls with heterogeneous educational levels from a geriatric outpatient clinic who completed the Cambridge Examination for Mental Disorder of the Elderly (CAMDEX). The CDT was evaluated according to the Shulman, Mendez and Sunderland scales.

Results: The CDT showed high sensitivity and specificity. There were significant correlations between the CDT and the MMSE (0.700–0.730; p < 0.001) and between the CDT and the CAMCOG (0.753–0.779; p < 0.001). The combination of the CDT with the MMSE improved sensitivity and specificity (SE = 89.2–90%; SP = 71.7–79.8%). Subgroup analysis indicated that for elderly people with lower education, sensitivity and specificity were both adequate and high.

Conclusions: The CDT is a robust screening test when compared with the MMSE or the CAMCOG, independent of the scale used for its interpretation. The combination with the MMSE improves its performance significantly, becoming equivalent to the CAMCOG.