TY - JOUR
T1 - Predicting the time of conversion to MCI in the elderly
T2 - Role of verbal expression and learning
AU - Oulhaj, Abderrahim
AU - Wilcock, Gordon K.
AU - Smith, A. David
AU - De Jager, Celeste A.
N1 - Funding Information:
During the course of the study, the principal grant support for OPTIMA came from Bristol-Myers Squibb, Merck & Co. Inc., Medical Research Council, Charles Wolfson Charitable Trust, Alzheimer's Research Trust, and Norman Collisson Foundation. Dr. Wilcock was partly supported by the NIHR Biomedical Research Centre, Oxford.
PY - 2009/11
Y1 - 2009/11
N2 - BACKGROUND:: Increasing awareness that minimal or mild cognitive impairment (MCI) in the elderly may be a precursor of dementia has led to an increase in the number of people attending memory clinics. We aimed to develop a way of predicting the period of time before cognitive impairment occurs in community-dwelling elderly. The method is illustrated by the use of simple tests of different cognitive domains. METHODS:: A cohort of 241 normal elderly volunteers was followed for up to 20 years with regular assessments of cognitive abilities using the Cambridge Cognitive Examination (CAMCOG); 91 participants developed MCI. We used interval-censored survival analysis statistical methods to model which baseline cognitive tests best predicted the time to convert to MCI. RESULTS:: Out of several baseline variables, only age and CAMCOG subscores for expression and learning/memory were predictors of the time to conversion. The time to conversion was 14% shorter for each 5 years of age, 17% shorter for each point lower in the expression score, and 15% shorter for each point lower in the learning score. We present in tabular form the probability of converting to MCI over intervals between 2 and 10 years for different combinations of expression and learning scores. CONCLUSION:: In apparently normal elderly people, subtle measurable cognitive deficits that occur within the normal range on standard testing protocols reliably predict the time to clinically relevant cognitive impairment long before clinical symptoms are reported.
AB - BACKGROUND:: Increasing awareness that minimal or mild cognitive impairment (MCI) in the elderly may be a precursor of dementia has led to an increase in the number of people attending memory clinics. We aimed to develop a way of predicting the period of time before cognitive impairment occurs in community-dwelling elderly. The method is illustrated by the use of simple tests of different cognitive domains. METHODS:: A cohort of 241 normal elderly volunteers was followed for up to 20 years with regular assessments of cognitive abilities using the Cambridge Cognitive Examination (CAMCOG); 91 participants developed MCI. We used interval-censored survival analysis statistical methods to model which baseline cognitive tests best predicted the time to convert to MCI. RESULTS:: Out of several baseline variables, only age and CAMCOG subscores for expression and learning/memory were predictors of the time to conversion. The time to conversion was 14% shorter for each 5 years of age, 17% shorter for each point lower in the expression score, and 15% shorter for each point lower in the learning score. We present in tabular form the probability of converting to MCI over intervals between 2 and 10 years for different combinations of expression and learning scores. CONCLUSION:: In apparently normal elderly people, subtle measurable cognitive deficits that occur within the normal range on standard testing protocols reliably predict the time to clinically relevant cognitive impairment long before clinical symptoms are reported.
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U2 - 10.1212/WNL.0b013e3181c0665f
DO - 10.1212/WNL.0b013e3181c0665f
M3 - Article
C2 - 19794124
AN - SCOPUS:70449367254
SN - 0028-3878
VL - 73
SP - 1436
EP - 1442
JO - Neurology
JF - Neurology
IS - 18
ER -