Yonsei Med J.  2013 Jul;54(4):825-831. 10.3349/ymj.2013.54.4.825.

Missing Data Analysis in Drug-Naive Alzheimer's Disease with Behavioral and Psychological Symptoms

• Kwak YT
• Yang Y
• Park SG

• KMID: 2158214
• DOI: http://doi.org/10.3349/ymj.2013.54.4.825

Abstract

PURPOSE
To clarify the effects of missing values due to behavioral and psychological symptoms in dementia (BPSD) in Alzheimer's disease (AD) patients on the neuropsychological tests, this study describes the pattern of missing values due to BPSD, and its influence on tests.
MATERIALS AND METHODS
Drug-naive probable AD patients (n=127) with BPSD and without BPSD (n=32) were assessed with Seoul Neuropsychological Screening Battery including measures of memory, intelligence, and executive functioning. Moreover, patients were rated on Korean Neuropsychiatry Inventory (K-NPI).
RESULTS
The more severe the K-NPI score, the less neuropsychological tests were assessable, leading to many missing values. Patients with BPSD were more severely demented than those without BPSD. K-NPI scores were significantly correlated with the number of missing values. The effect of BPSD was largest for tests measuring frontal functions. The replacement of the missing values due to BPSD by the lowest observed score also showed the largest effect on tests of frontal function.
CONCLUSION
The global cognitive and behavior scales are related with missing values. Among K-NPI sub-domains, delusion, depressing, apathy, and aberrant motor behavior are significantly correlated for missing values. Data imputation of missing values due to BPSD provides a more differentiated picture of cognitive deficits in AD with BPSD.

Keyword

BPSD; missing values; drug-naive; Alzheimer's disease; K-NPI

MeSH Terms

Aged
Alzheimer Disease/*psychology
Behavioral Symptoms
Cognition
Delusions
Dementia/psychology
Female
Humans
Male
Neuropsychological Tests
Regression Analysis