The validity of informant report for grading the severity of Alzheimer's dementia.

The validity of informant-based techniques has been established for the detection of dementia cases by non-pathological individuals, but is still controversial for the assessment of the severity of dementia. This study aimed at ascertaining whether informant-based evaluation (the so-called informant report) of the cognitive and behavioral impairment of a patient is valid for grading the severity of dementia, and consistent with objective assessment of the patient's cognitive and behavioral functioning. We enrolled 96 community-dwelling outpatients and 56 controls assessed at the Geriatric Evaluation Unit of the University of Modena, Italy. All patients scored lower than 27 on the MMSE, and met DSM-IV inclusion criteria for Alzheimer's dementia. Patients and controls were administered the CAMDEX interview, containing a section which collects participant (patient or control) and informant evaluations on dementia-related cognitive and behavioral deficits. The informant report resulted effective at MANOVA for grading the severity of dementia in 4 of its 5 measures (namely, memory, everyday activities, general mental functioning and depressed mood), and was correlated with the scores of several scales of the CAMDEX cognitive section (i.e., CAMCOG). Instead, the participant's (patient or control) report showed a lower capacity for grading dementia, and was poorly correlated with the psychometric outcomes of cognitive functioning. On the whole, the results corroborated the validity of the informant report in the diagnostic work-up for grading dementia, given its sensitivity to the severity of dementia, and its consistency with cognitive psychometric outcomes.

Validation of the full and short forms of the CAMDEX interview for diagnosing dementia: evidence from a one-year follow-up study.

The sensitivity and specificity of the two forms of the CAMDEX interview for dementia diagnosis were assessed in a 1-year follow-up study. At the beginning of the study, 60 patients (22 males and 38 females) who met DSM-IV criteria for dementia and 60 matched controls (15 males and 45 females), were administered the short form of the CAMDEX (short CAMDEX) 3 months after the full one (full CAMDEX). At the follow-up, all patients were administered both the full and short CAMDEX (again with a 3-month interval), whereas controls were administered either CAMDEX form (in any case, at a 12-month interval from initial testing). Upon initial testing, the sensitivity of the full CAMCOG proved to be significantly higher than that of the short CAMCOG, while the opposite trend was observed for specificity, that is the sensitivity of the full Organicity was lower than that of the short Organicity, with specificity remaining equal in the two forms. Upon follow-up, the specificity and sensitivity levels of the two forms did not significantly differ for the CAMCOG and Organicity indices. Moreover, in detecting mildly demented patients, the full CAMCOG proved to be more accurate than the short one, while the opposite trend was observed for Organicity. Among the dementia subjects, significant correlations were found between the homologous indices of the two forms for both test sessions. On the whole, the short CAMDEX appears to maintain most of the psychometric properties of the full version and therefore the two CAMDEX forms can be considered to be interchangeable.