FUNCTIONAL EVALUATION DISTINGUISHES MCI PATIENTS FROM HEALTHY ELDERLY PEOPLE - THE ADCS/MCI/ADL SCALE pot

Several studies have shown a significantly higher frequency of functional impairment in patients with MCI when compared to the normal FUNCTIONAL EVALUATION DISTINGUISHES MCI PATIENTS FRO

Due to the progressive aging of the population, there is

increasing concern and interest on age-related disorders, with

the aim of promoting as much autonomy and quality of life as

possible in the elderly

The concept of activities of daily living (ADL) as an

expression of the functional state was introduced by Katz (1)

and developed by Lawton, who proposed dividing ADL in

basic activities (BADL), such as eating, taking care of the

hygiene, using the bathroom or getting dressed; and

instrumental activities (IADL), more demanding in terms of

cognitive function, such as shopping, handling money, cooking,

housekeeping and using the telephone (2) These abilities of

daily living define how independently people live They rely on

cognitive functions like memory and attention, but also on

automatic procedures (procedural memory), strengthened by

habits and routines that often guarantee some level of

independence, despite eventual progressive cognitive

impairments (3) More recently, the concept of complex

activities of daily living (CADL) was developed, which

involves superior cognitive functions, translated in activities

like the ability to maintain a job, travel and plan travelling,

participate in groups or community movements, drive, plan

events or play games (4) Functional evaluation is sensitive to

slight changes in cognition, namely memory, attention and

executive functions that may not be easily identified through

routine neuropsychological testing (5) but play an important role in the early difficulties that patients experience in their real life context Thus, even slight changes in cognitive function may be sufficient to produce gradual loss of CADL and subsequently IADL (3, 6, 7)

The concept of Mild Cognitive Impairment (MCI) has evolved in the last decade to characterize a transitional state between normal cognitive aging and dementia Patients with MCI have cognitive complaints and objective impairment in memory and/or other cognitive domains, without major repercussions in daily life, and are not demented (8) MCI is a condition that often progresses to dementia; in particular, amnestic MCI is frequently an incipient stage of Alzheimer’s disease (AD) (9) Thus, diagnosis of MCI may lead to an adequate early intervention allowing patients and families to do

a more appropriate long term planning of their lives (10) One of the requisites in the original MCI diagnosis criteria is maintenance of normal activities of daily living (8) According

to a recent revision of these criteria, patients should have no difficulties with BADL, but can have slight impairments in IADL and CADL (11) It is presently recognized that keeping the absence of impairment in all activities of daily living as a diagnostic criteria would probably be too restrictive, resulting

in an underestimation of the MCI prevalence (3, 12) and hindering the ability to predict dementia (5) Several studies have shown a significantly higher frequency of functional impairment in patients with MCI when compared to the normal

FUNCTIONAL EVALUATION DISTINGUISHES MCI PATIENTS

FROM HEALTHY ELDERLY PEOPLE - THE ADCS/MCI/ADL SCALE

H PEDROSA1, A DE SA2, M GUERREIRO1,3, J MAROCO4, M.R SIMOES5,

D GALASKO6, A DE MENDONCA1,7

1 Dementia Clinics, Institute of Molecular Medicine and Faculty of Medicine of Lisbon, Lisbon, Portugal; 2 Neurology Clinics, Hospital of Santo André, Leiria, Portugal; 3 Laboratory

of Language, Institute of Molecular Medicine and Faculty of Medicine of Lisbon, Lisbon, Portugal; 4 Superior Institute of Applied Psychology, Lisbon, Portugal; 5 Psychological Assessment Service, Faculty of Psychology and Educational Sciences of the University of Coimbra, Coimbra, Portugal; 6 Department of Neurosciences, University of California, San Diego, US; 7 Laboratory of Neurosciences, Institute of Molecular Medicine and Faculty of Medicine of Lisbon, Lisbon, Portugal Corresponding author and reprint requests: Alexandre de Mendonça, Laboratory of Neurosciences, Institute of Molecular Medicine, Av Prof Egas Moniz, 1649-028 Lisbon, Portugal, Telephone 351217985183,

Telefax, 351217999454, mendonca@fm.ul.pt

Abstract: Patients with MCI may present minor impairments in activities of daily living (ADL) The main

objective of this work was to evaluate the ability of two versions of the Alzheimer's Disease Cooperative Study /

Activities of Daily Living scale adapted for MCI patients (ADCS/MCI/ADL18 and ADCS/MCI/ADL24) to

distinguish patients with MCI from healthy control subjects Participants were 60 years or older and community

dwelling: 31 control subjects, 30 aMCI patients and 33 AD patients A protocol of neuropsychological tests,

global evaluation scales, functional scales, and depressive symptoms assessment was used Activities of

balancing the cheque book, using a telephone, going shopping, taking medication regularly, finding objects,

talking about current events, watching television, initiating complex activities, keeping appointments or

meetings, reading, getting around outside the home and driving a car were impaired in aMCI patients The

ADCS/MCI/ADL24 scale was better than the ADCS/MCI/ADL18 scale in distinguishing aMCI patients from

healthy controls (sensitivity=0.87, specificity=0.87, ROC c=0.887, cut-off point=52/53) The detection of initial

functional changes with appropriate scales may contribute to the early diagnosis of MCI and the development of

targeted interventions to improve everyday function or prolong independence.

Key words: Mild Cognitive Impairment, functional evaluation, activities of daily living, ADCS/MCI/ADL,

Alzheimer’s disease.

JNHA: CLINICAL TRIALS AND AGING

FUNCTIONAL EVALUATION IN MCI

population (3, 5, 6, 13, 14) In the PAQUID project (5), those

patients with MCI who presented impairment in IADL had

greater probability to progress to dementia, and less chances of

going back to normality after 2 years, when compared to

patients with MCI but without functional impairment

Despite the value of complementing neuropsychological

evaluation with functional measures in MCI patients, there are

still no recommended instruments, reference values or objective

orientations regarding the degree of ADL impairment in this

population (3, 5, 12) In fact, most available instruments were

usually designed to evaluate people with dementia, and are not

sensitive enough to detect changes in patients in the initial

phases of cognitive decline, like MCI patients (10, 11, 14-16)

The development and generalization of new instruments

designed to evaluate daily function in subjects with MCI would

allow a detailed characterization of the ADL changes in these

patients and possibly, when added to the neuropsychological

evaluation, lead to a more accurate diagnosis of the condition

The Alzheimer's Disease Cooperative Study / Activities of

Daily Living scale for MCI patients (ADCS/MCI/ADL) is a

functional evaluation scale for MCI patients, based on the

information provided by an informant/carer, that describes the

performance of patients in several activities of daily living It

was adapted by Douglas Galasko and co-workers from the

original ADCS/ADL scale, which was constructed to evaluate

patients with dementia in the Alzheimer’s Disease Cooperative

Study, as a measure of the AD patients’ performance in ADL

(17) The ADCS/MCI/ADL has been used in several studies

and clinical trials to monitor the evolution of patients with MCI

(6, 7, 18, 19) After the development of the ADCS/MCI/ADL

18 items scale, the authors decided to add 6 experimental items,

considered more appropriate to the MCI population – this

version with 24 items will be henceforth referred to as the

ADCS/MCI/ADL24 (and the 18 items version will be further

referred to as the ADCS/MCI/ADL18)

Presently, to our knowledge, only one study determined the

sensitivity and specificity values for the diagnosis of MCI

versus controls, using the shorter version of the scale (7) The

main objective of this work is to compare the ability of both

ADCS/MCI/ADL24) in distinguishing patients with MCI from

healthy controls Other objectives are to evaluate the ability of

the scale to distinguish patients with MCI from patients with

AD, and to characterize the main functional features that

differentiate healthy controls, patients with MCI, and patients

with AD

Methods

Participants

Participants were patients with MCI and patients with AD

attending two Memory Clinics and a hospital neurology

outpatient clinic For reasons of sample homogeneity, only

patients with the amnestic type of MCI (aMCI) were recruited

Control subjects were volunteers, usually spouses or friends of patients who were requested to participate in the study The ADL reports from all groups were collected from an informant/caregiver who lived with the subject or regularly spent time with the subject (mostly spouses or sons/daughters) The study was approved by the local ethics committee Before any procedure, the participants gave their informed consent

To be eligible for the study, all participants had to be 60 years or older and community dwelling Specific inclusion criteria for the groups were:

Control group

(1) No evidence for cognitive deterioration or cognitive complaints;

(2) Mini Mental State Examination (MMSE) above cut-off (see below);

(3) Immediate free recall of story A from the Logical Memory (LM) subtest of the Wechsler Memory Scales above cut-off (see below);

(4) Maintained activities of daily living as evaluated by normal Lawton Instrumental Activities of Daily Living (LIADL) scale, that is to say, no item from this scale suffered any change

aMCI

Inclusion criteria for aMCI were adapted from the criteria proposed by the Working Group in MCI of the European Alzheimer’s Disease Consortium (12, 13):

(1) Cognitive complaints and cognitive decline during the last year, reported by the patient and/or family;

(2) MMSE above cut-off;

(3) Immediate free recall of story A from the Logical Memory subtest of the Wechsler Memory Scales at least 1 standard deviation (SD) below the norm for age and education; (4) Maintained activities of daily living or slight impairment

in instrumental activities of daily living, in other words, no more than one item from the LIADL scale suffered any changes (20);

(5) Absence of dementia, according to the DSM IV – TR criteria (21)

AD

Diagnosis of the AD patients was based on the DSM IV –

TR criteria (21)

Exclusion criteria for all groups:

(1) Presence of other neurological and/or psychiatric pathologies that could cause cognitive impairment;

(2) History of alcohol or drug abuse;

(3) Symptoms of severe depression, that is, Geriatric Depression Scale (GDS) > 20

Of the 108 participants initially evaluated, 14 were excluded from the study for the following reasons: severe depression symptoms at time of evaluation (GDS>20), which could be a confounding variable in the MCI diagnosis (n=2); history of

JNHA: CLINICAL TRIALS AND AGING

stroke (n=7); psychiatric illness (n=1); lack of collaboration

from the caregiver, being in a hurry (n=2); controls with low

performance in neuropsychological tests (n=2)

Procedures

All aMCI and AD cases were subjected to clinical history,

neurological examination, laboratorial evaluation and brain

imaging (CT scan or NMR scan) (22) All participants had the

same evaluation protocol which comprised:

(1) Mini Mental State Examination (MMSE) (23) The

MMSE is widely used for brief evaluation of the mental state

and screening of dementia; the normative cut-off values for the

Portuguese population adjusted to education were used (24)

Subjects had to score above 22 if they had ≤11 years of

education, or above 27 if they had >11 years of education

These cut-off values adjusted to the education levels were

similar to those found in other studies (25, 26)

(2) Logical Memory subtest from the Wechsler Memory

Scale (WMS) (27), which is included in the Battery of Lisbon

for the Evaluation of Dementia (BLAD) (28) Memory was

considered impaired when the subjects scored on immediate

free recall of story A of the test at least 1 standard deviation

(SD) below the normal for age and education Although in

other studies performance was considered abnormal when

scores are 1.5 SD below the mean for age and education

matched control subjects, there is no standard cut-off to

implement the memory impairment criteria (11, 29) A cut-off

value of 1 SD was adopted considering that it allows the

identification of subjects with slight cognitive changes but

already fulfilling MCI criteria and at a high risk of developing

dementia; also, the use of the cut-off value of 1.5 SD could

exclude subjects that from a clinical point of view suffered

from MCI (30)

(3) Geriatric Depression Scale (GDS) (31, 32) The GDS is a

self-report assessment used specifically to evaluate depression

in the elderly The complete version (30 items) was used for

this study

(4) Clinical Dementia Rating Scale (CDR) (32, 33) The

CDR is a structured-interview protocol that assesses the

cognitive and functional performance in six areas: memory,

orientation, judgment and problem solving, community affairs,

home and hobbies and personal care, in order to quantify the

severity of dementia symptoms

(5) Blessed Dementia Rating Scale (BDRS) (32, 34) The

BDRS is a brief behavioural scale based on an interview to a

close informant, assessing functional ability for activities of

daily living and changes in personality

(6) Lawton Instrumental Activities of Daily Living Scale

(LIADL) (2, 32) The LIADL score reflects the number of

impaired activities and ranges from 0 (no impairment) to 8

(changes in all items) Items were classified as not applicable if

the activity had never been done before or if the subject

stopped doing it for reasons other than cognitive difficulty (35)

Activities of daily living were considered preserved if no item

if only one item from the LIADL scale was altered (20) (7) The Alzheimer's Disease Cooperative Study / Activities

of Daily Living scale for MCI patients (ADCS/MCI/ADL) is a functional scale based on the information provided by an informant/caregiver that describes the performance of patients

in several activities of daily living (17) The original version of ADCS/MCI/ADL comprises 18 items (ADCS/MCI/ADL18,

(ADCS/MCI/ADL24, score of 0 to 69) has 6 further items and

is considered more adapted to the MCI population

Statistical Analysis

Statistical analysis was performed using Statistical Package for the Social Sciences (SPSS 15.0, SPSS Inc: Chicago, IL) A significance level = 0.05 was used in all analyses The outliers analysis was done taking into account the primary variable in the study – ADCS/MCI/ADL No outliers (defined

as values 1.5 times lower than the 1st quartile or 1.5 times higher than the 3rd quartile) (36) were found in all the groups

We checked the homogenous distributions of the demographical variables, namely age and education with ANOVA one-way and sex with the Chi-square test

In what regards the functional description of the groups, we analysed participation frequencies in the tasks/activities defined

in the items of the scale and searched for significant differences among the groups in each item, using Kruskal-Wallis non-parametric ANOVA followed by LSD on ranks (36) (the Chi-square test was used for item 24) This procedure was also used

to search for significant differences in the neuropsychological evaluation among groups, since the assumption of normal distribution and homogeneity of variances was not fulfilled in neuropsychological evaluation tests

We defined cut-off points for both versions of the scale and studied the scale sensitivity and specificity values for each cut-off point After defining the cut-cut-off point with the best sensitivity and specificity values, we determined the discriminant performance of the scale, observing the Receiver Operating Characteristic curve (ROC) (36) and compared the Areas Under the Curve (AUC) with the Z test (37) to check for significant differences between both versions of the scale

Results

Ninety-four participants (55 women and 39 men) were included in the study, divided in 3 groups: control (n=31); aMCI (n=30) and AD (n=33) There were no statistical differences among the groups regarding the demographical variables (Table 1)

neuropsychological tests, MMSE and Logical Memory, as well

as in global scales, CDR and Blessed Dementia Scale, and in functional scales, Lawton and ADCS/MCI/ADL (Table 1) Regarding evaluation of depressive symptoms, there were significant differences in the GDS scores between the aMCI and AD, and control and AD groups, but not between the control and the aMCI groups (Table 1)

FUNCTIONAL EVALUATION IN MCI

706

Table 1

Demographical variables and results in neuropsychological tests, global evaluation scales, functional scales, and depressive symptoms in control subjects, patients with aMCI and patients with AD MMSE, Mini Mental State Examination; LM, Logical Memory subtest from the Wechsler Memory Scale; CDR, Clinical Dementia Rating Scale; GDS, Geriatric Depression Scale; BDRS, Blessed Dementia Rating Scale; LIADL, Lawton Instrumental Activities of Daily Living Scale; ADCS/MCI/ADL, Alzheimer's Disease Cooperative Study / Activities of Daily Living scale adapted for aMCI patients Significant differences among the groups were assessed with one-way ANOVA for age and education, the Chi-square for sex, and Kruskal-Wallis

non-parametric ANOVA followed by LSD on ranks for all the other measures NS = not statistically significant

Control aMCI AD Statistics p-value Statistical significance

Age (years) Mean (SD) 72.2 (8.0) 75.7 (6.4) 76.1 (7.5)

KW (2) = 53.13 < 0.001 C > MCI > AD

KW (2) = 56.56 < 0.001 C > MCI > AD

KW (2) = 89.41 < 0.001 C < MCI < AD

KW (2) = 13.70 < 0.001 C, MCI < AD

KW (2) = 66.32 < 0.001 C < MCI < AD

KW (2) = 45.15 < 0.001 C > MCI > AD ADCS MCI ADL18 47.0 (4.2) 39.6 (6.3) 17.8 (11.8) X 2

KW (2) = 66.86 < 0.001 C > MCI > AD ADCS MCI ADL24 59.3 (6.7) 46.7 (8.3) 20.7 (13.2) X 2

KW (2) = 69.49 < 0.001 C > MCI > AD

Table 2

Performances in the distinct items of ADCS/MCI/ADL scale in controls, aMCI patients, and AD patients The mean (SD) scores are shown Statistical significance was tested using Kruskal-Wallis non-parametric ANOVA followed by LSD on ranks except for item 24, where the Chi-square test was used – item 24: percentage of subjects who experienced an extraordinary circumstance that

could influence performance in ADL NS = not statistically significant

1 – finding personal belongings 3.0 (0.2) 2.6 (0.5) 1.5 (0.8) C > MCI > AD

5 – balancing the cheque book 1.3 (0.9) 0.9 (0.9) 0.0 (0.2) C > MCI > AD

12 – talking about current events 3.8 (0.4) 2.7 (1.1) 1.6 (1.5) C > MCI > AD

13 – reading for over 5 minutes 2.4 (1.2) 1.5 (1.2) 0.4 (0.8) C > MCI > AD

21 – carrying through complex activities 2.3 (1.3) 0.9 (1.4) 0.2 (0.8) C > MCI, AD

22 – initiating complex activities 1.7 (1.4) 0.5 (1.1) 0.0 (0.2) C > MCI, AD

23 – time taken to perform complex tasks 2.5 (0.9) 2.2 (0.6) 1.1 (1.0) C > MCI > AD

JNHA: CLINICAL TRIALS AND AGING

Table 3

Capability of the ADCS/MCI/ADL scale (18-item and 24-item versions) to distinguish among controls, aMCI patients and AD

patients AUC, Area Under the Curve, Receiver Operating Characteristic curve

Version of the scale Groups Mean (SD) Cut-off point Sensitivity Specificity AUC False False

Negatives Positives

ADCS MCI ADL18 Control 46.6 (5.3)

aMCI 39.5 (6.5) aMCI 39.5 (6.5)

AD 17.8 (11.8) ADCS MCI ADL24 Control 58.9 (7.7)

aMCI 46.7 (8.3) aMCI 46.7 (8.3)

AD 20.7 (13.2)

Figure 1

Frequencies of the participation of controls, aMCI patients and AD patients in the tasks (1 to 22) evaluated by the ADCS/MCI/ADL scale See Table 2 for characterization of the specific items of the scale Item 23 is not shown because it relates

to the speed on performance of complex activities Item 24 is also not shown because it inquires about exceptional circumstances

that could interfere with the performance of ADL

Figure 2

Receiver Operating Characteristic (ROC) curves for the discrimination between controls and MCI (A) using the

ADCS/MCI/ADL18 (ROC c=0.842) and the ADCS/MCI/ADL24 (ROC c=0.887) were significantly different (z=1.97; p=0.049) -ADCS/MCI/ADL24 is superior in distinguishing MCI patients from healthy controls ROC curves for the discrimination between MCI and AD patients (B) using the ADCS/MCI/ADL18 (ROC c=0.956) and ADCS/MCI/ADL24 (ROC c=0.955) were not

significantly different (z=0.043; p=0.965)

The frequencies in which the three groups participated in the

tasks evaluated by the ADCS/MCI/ADL are shown in Figure 1

Comparison of the scores in the distinct items of the

ADCS/MCI/ADL scale for the three groups of subjects is

shown in Table 2 Patients with aMCI were impaired relatively

to healthy controls in demanding tasks, whereas they performed

well in more basic tasks, where only AD patients had

difficulties (Table 2)

The capability of the ADCS/MCI/ADL to distinguish among

controls, aMCI patients and AD patients was analysed The

cut-off points that best discriminate between controls and aMCI

patients, and between aMCI patients and AD patients, for both

ADCS/MCI/ADL18 and ADCS/MCI/ADL24, are shown in

Table 3 Although AUC analysis revealed good discriminant

capacity for both versions of the scale, ADCS/MCI/ADL24

presented higher values for the discrimination between aMCI

patients and healthy controls, with good sensitivity (0.87) and

specificity (0.87) values, and a high discriminant performance

(ROC c=0.887; 95% Confidence Interval ]0.802-0.972[; cut-off

point of 52/53) (Figure 2 and Table 3) The shorter

ADCS/MCI/ADL18 scale version had only moderate

sensitivity (0.73) and specificity (0.74) values, and a lower

discriminant performance (ROC c=0.842; 95% Confidence

Interval ]0.747-0.938[; cut-off point of 45/46), in distinguishing

aMCI patients from healthy controls The comparison of the

AUC with the Z test (38) revealed the ROC curves for Control

vs aMCI were significantly different (z=1.97; p=0.049) but not

for the aMCI vs AD patients (z=0.043; p=0.965) Thus,

ADCS/MCI/ADL24 was superior to ADCS/MCI/ADL18 in

distinguishing aMCI patients from healthy controls, but not

aMCI from AD patients

Discussion

The detection of subjects in the initial phases of cognitive

decline, as in MCI, may be difficult Research criteria require

the use of sensitive memory and learning tests, which are not

always available in routine clinical practice Inquiry about

IADL performance to obtain a total score and to assess the

types of IADL that are impaired could offer a way to

complement mental state testing The detection of mild

functional disturbances, predominantly involving complex

activities, could allow a better distinction of MCI patients from

healthy elderly people (11) The present study showed that the

ADCS/MCI/ADL24 scale had a high accuracy and was

superior to ADCS/MCI/ADL18 scale in distinguishing aMCI

patients from healthy controls A previous study presented

sensitivity and specificity values for the ADCS/MCI/ADL18

scale, however, a different scoring system was used, from 0 to

57 (7), instead of 0 to 53, precluding direct comparison with the

present results The increase in diagnostic efficiency of

ADCS/MCI/ADL24 towards ADCS/MCI/ADL18 can be

explained by the nature of the items introduced in the last part

of the scale, which refer to complex abilities, like driving a car

or organizing the medication, where subtle difficulties may be revealed in MCI patients Thus, the ADCS/MCI/ADL24 is a sensitive and specific instrument to aid in accurately discriminating aMCI patients from healthy elderly people In contrast, regarding the distinction between aMCI and AD patients, both versions of the scale, ADCS/MCI/ADL24 and ADCS/MCI/ADL18, performed similarly, since the complex items introduced in the final part of ADCS/MCI/ADL24 should

be difficult for both aMCI patients and AD patients

Main functional features differentiate healthy controls, patients with aMCI, and patients with AD In general, MCI subjects have an intermediate performance, between the control group and the AD group (38) We found a functional decline from the control group to the aMCI group and from this to the

AD group, both in the total ADCS/MCI/ADL score and in the number of activities in which all patients participated This corroborates previous studies that showed significantly lower scores in the MCI patients when compared to healthy controls (7) and in AD patients when compared to MCI patients (19) Because functional impairment is part of the diagnosis of AD, and patients with moderate AD (mean MMSE of 16), were enrolled, we found that the AD group was impaired across a wide range of IADL activities There was a clear gradient of progressive functional decline from controls to aMCI and then

to AD

It is interesting that decline in daily activities follows a specific pattern, so that higher order functional abilities tend to decline first, and basic activities of daily living are affected last Among the ADCS/MCI/ADL questions, those that are highly dependent on memory, planning and sustained attention also appeared to be the earliest and most severely affected in aMCI

in our study Recent studies in a Canadian cohort, with participants over 65 years old, showed this relationship between loss of specific ADLs and the cognitive status at the beginning

of the functional loss (39), although there might be overlapping

in some activities Furthermore, the instrumental activities performed away from home tend to get affected earlier than do those usually performed at home (3, 39)

The activities that we found to decline in aMCI patients as compared to healthy controls were controlling the cheque book, using a telephone, going shopping, taking medications regularly, finding objects, talking about current events, watching television, initiating complex activities, keeping appointments or meetings, reading and carrying through complex activities Interestingly, this decline was also found in previous studies, even when using different scales (10, 40) The present study also identified the tasks of getting around outside the home and driving a car as affected in aMCI patients as compared to controls The activities in which the MCI patients begin to show impairment seem to depend on large cognitive resources, namely memory, psychomotor speed, attention and executive functions (38), although these patients can still perform basic activities of daily living just as well as healthy controls As the disease progresses, and AD is diagnosed,

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708

patients show significant limitations in most items, and initiate

obvious difficulties in basic ADL, that are not shared either by

controls or by MCI patients

Several limitations must be recognized in the present study

The MCI patients that were recruited were of the amnestic type,

and no information was obtained regarding other MCI types

On the other hand, the characteristics of patients being seen in a

clinical setting may differ from individuals in the community

that fulfil criteria for MCI but did not actively seek clinical

evaluation, and thus the present results may not generalize to

community-based MCI samples

The detection of initial functional changes with appropriate

scales may contribute to the early diagnosis of MCI, and may

also identify those patients who are at greater risk for further

decline (41) The present study showed that the

ADCS/MCI/ADL24 scale has a high accuracy in distinguishing

aMCI patients from healthy controls The early detection of

these patients and the recognition of specific difficulties should

allow timely and targeted interventions to improve everyday

function or prolong independence

Acknowledgements: Supported by grants from Fundação Calouste Gulbenkian and

Fundação para a Ciência e Tecnologia The authors acknowledge the facilities provided by

Memoclínica and Hospital de Santo André, EPE.

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