Because of recent advances in treatment options, accurate assessment and diagnosis of dementia takes on a new significance. Since cognitive impairment is the central symptom of this disorder, screening devices have been developed to identify patients earlier in the disease process. Two of these screening devices include the Mini-Mental State Examination and the Informant Questionnaire on Cognitive Decline in the Elderly. The latter device is a 16-item questionnaire that is completed by a person who knows the patient well. Mackinnon and Mulligan studied the effectiveness of combining these two instruments to screen for cognitive impairment.
Study participants presented to a geriatric hospital or memory clinic without an established diagnosis of dementia. Patients were 62 to 98 years of age; 76 were women and 30 were men, and 59 had not completed high school. Each patient was given a Mini-Mental State Examination, and a person who knew the patient well completed the Informant Questionnaire on Cognitive Decline in the Elderly. Patients were also evaluated to determine whether they met the criteria for dementia as given in the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV).
Fifty-eight patients met DSM–IV criteria for dementia. The mean score for the Mini-Mental State Examination was 22.5, and the mean score for the informant questionnaire was 3.87. The mean scores for patients diagnosed with dementia differed substantially from those of patients who were not diagnosed with this disorder. Each screening device identified a significant number of the patients with dementia, but combining the results of the two tests improved the percentage of patients with dementia who were identified.
The Mini-Mental State Examination and the Informant Questionnaire on Cognitive Decline in the Elderly appeared to be complementary components in the assessment of geriatric patients who may have dementia. Used together, the tests provided more information than either test used alone.
The authors conclude that while each screening device has some advantages, a combination of the two can improve the accuracy of diagnosis of dementia. Both instruments are easy to use in the clinical setting and can improve the quality of screening for dementia.