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Trial registered on ANZCTR


Registration number
ACTRN12617000195358
Ethics application status
Approved
Date submitted
2/02/2017
Date registered
6/02/2017
Date last updated
1/02/2018
Type of registration
Retrospectively registered

Titles & IDs
Public title
Use of the Australian Modified Lawton’s Instrumental Activities of Daily Living Scale in the diagnosis of dementia.
Scientific title
Use of the Australian Modified Lawton’s Instrumental Activities of Daily Living Scale in the differential diagnosis of cognitive impairment.
Secondary ID [1] 291060 0
None
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Memory Loss 301858 0
Condition category
Condition code
Neurological 301537 301537 0 0
Dementias
Neurological 301538 301538 0 0
Alzheimer's disease

Intervention/exposure
Study type
Observational
Patient registry
False
Target follow-up duration
Target follow-up type
Description of intervention(s) / exposure
Like most western countries, Australia is currently facing a dementia epidemic. The prevalence of dementia in Australia is expected to reach over 1.1 million in 2050 (Alzheimer's Australia, 2009). By the 2060s, spending on dementia is set to outstrip that of any other health condition (Alzheimer's Australia, 2015)..

Dementia syndrome affects a person in the three domains of cognition, behaviour and function. Impairment of functional abilities represents a crucial and necessary component of dementia diagnosis (McGrory S, Shenkin S, Austin E & Starr J, 2014). Therefore, functional or daily living skills assessment must play a major role in contributing to cognitive diagnosis. However, how a quantitative measurement of activities of daily living (ADL) can contribute to the differential diagnoses, similar to the use of cognitive function tests, has not been extensively studied.

The Lawton’s Instrumental Activities of Daily Living (IADL) Scale is a popular, reliable and validated instrument to assess independent living, and has been endorsed by the Australian Government for the use in various Aged Care Service Programmes.

The aim of this study is to investigate the ability of the Australian Modified Lawton’s IADL scale (revised version of the Lawton’s IADL Scale) to differentiate cognitive diagnoses by determining ‘cut-off’ scores between Normal Cognition (NC), Mild Cognitive Impairment (MCI), and Dementia (D). The availability of this objective measure would contribute significantly to an earlier and more confident cognitive diagnosis.

The Timed Up and Go (TUG) is a commonly used measure of functional mobility and dynamic balance. Recently the TUG has been associated with the assessment of patients for early cognitive changes, discriminating between patients with normal cognition (NC), MCI and D. A secondary aim is to compare performance on the TUG between elderly subjects with NC, MCI and D to determine if the TUG could add value to the assessment of patients in a memory clinic setting.

An Occupational Therapist (OT) will assess Sir Charles Gairdner Hospital (SCGH) Memory Clinic patients prior to medical assessment and therefore clinical diagnosis. The Australian Modified Lawton’s IADL scores are then compared to the eventual diagnosis made by the Geriatrician (Principal Investigator) and the multidisciplinary team. This analysis will determine the range of scores on the IADL scale for the three diagnostic groups, NC, MCI and D, and the cut-off points between groups.
Intervention code [1] 297048 0
Diagnosis / Prognosis
Comparator / control treatment
No control group.
Control group
Uncontrolled

Outcomes
Primary outcome [1] 300938 0
Australian Modified Lawton’s IADL scale score
Timepoint [1] 300938 0
On presentation to Memory Clinic
Primary outcome [2] 300939 0
Cognitive diagnosis by Geriatrician
Timepoint [2] 300939 0
On presentation at Memory Clinic
Secondary outcome [1] 331247 0
Mini Mental State Examination (MMSE) score
Timepoint [1] 331247 0
On presentation at Memory Clinic
Secondary outcome [2] 342674 0
Timed Up and Go Score
Timepoint [2] 342674 0
At each patient assessment

Eligibility
Key inclusion criteria
Inclusion criteria

- Patients newly referred to the Memory Service, Day Therapy Unit Department of Rehabilitation and Aged Care at SCGH.
- Sufficient English to communicate and participate in discussion and demonstration of daily living skills.

Minimum age
No limit
Maximum age
No limit
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Exclusion criteria

- Comorbid medical conditions with significant physical impairment.
- Major psychiatric disorder and/or behavioural problems
- Significant cerebrovascular disease
- Significant impairment of vision, hearing or communication

Study design
Purpose
Screening
Duration
Cross-sectional
Selection
Convenience sample
Timing
Prospective
Statistical methods / analysis
Sample Size Calculation:
Previous data indicates that the diagnostic rates in the SCGH memory clinic of D, MCI and NC controls are approximately 63%, 22% and 15%, respectively and that a significant relationship exists between diagnostic groups and the Modified Lawton’s score (p<0.0001). Following the guidelines set out by Peduzzi et al. where p represents the proportion of the population with the response and k the number of covariates considered (1 – Modified Lawton’s Score) in the logistic regression model, the total sample size required for modelling the responses in dementia and healthy controls is 54 and 131, respectively.

Internal validation of the cut-off scores (as determined from ROC analyses) will be conducted with a hold out sample. It is estimated that over the time period of the study, 250 cases will be attainable. This will allow for a 60:40 split of the data for initial (N=150) and validation (N=100) datasets whilst also satisfying the minimum sample size required for the logistic regression analyses.

Statistical Analysis Plan:
Data from 250 patients will be separated into a training set (N=150) and a validation set (N=100) with an equal mix of NC, MCI and D patients in each set. Data from the training group will be used to determine the optimal Lawton Score cut-offs whilst data from the validation group will be used to prospectively assess the accuracy of these cut-offs. Cut-offs will be determined using two logistic regression models with receiver operator characteristic curves. The first analysis will compare NC to MCI and D patients combined to determine the Modified Lawton’s Score that separates healthy patients from the rest. The second analysis will compare D patients to NC and MCI patients combined in order to determine the Modified Lawton’s Score that separates D patients from the rest.

A parallel analysis will also be conducted similar to above where the MMSE score will be used as the response. As the MMSE has been shown to categorise NC, MCI and D patients with a high degree of accuracy we will compare the predictions to those from the Modified Lawton’s score. Correlations between MMSE and Modified Lawton’s will also be investigated.

All statistical analyses will be conducted using the R environment for statistical computing.

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
WA
Recruitment hospital [1] 7426 0
Sir Charles Gairdner Hospital - Nedlands
Recruitment postcode(s) [1] 15231 0
6009 - Nedlands

Funding & Sponsors
Funding source category [1] 295501 0
Hospital
Name [1] 295501 0
Sir Charles Gairdner Hospital Occupational Therapy
Address [1] 295501 0
Occupational Therapy Department
Lower Ground Floor, G Block
Hospital Avenue
Nedlands 6009 WA
Country [1] 295501 0
Australia
Primary sponsor type
Hospital
Name
Sir Charles Gairdner Hospital Occupational Therapy
Address
Occupational Therapy Department
Lower Ground Floor, G Block
Hospital Avenue
Nedlands 6009 WA
Country
Australia
Secondary sponsor category [1] 294321 0
None
Name [1] 294321 0
None
Address [1] 294321 0
None
Country [1] 294321 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 296829 0
Sir Charles Gairdner Hospital Ethics Committee
Ethics committee address [1] 296829 0
Sir Charles Gairdner Hospital
A Block
Hospital Avenue
Nedlands WA 6009
Ethics committee country [1] 296829 0
Australia
Date submitted for ethics approval [1] 296829 0
16/02/2016
Approval date [1] 296829 0
21/04/2016
Ethics approval number [1] 296829 0
HREC No: 2016-025

Summary
Brief summary
AIM

The aim of this study is to investigate the ability of the Australian Modified Lawton’s IADL scale to differentiate cognitive impairment by determining ‘cut-off’ scores between Normal Cognition (NC), Mild Cognitive Impairment (MCI), and Dementia (D).

HYPOTHESIS

The Australian Modified Lawton’s IADL scale scores will have significant association with the diagnoses of MCI and D, hence contribute to the assessment and diagnosis of older persons presenting with cognitive decline according to standard diagnostic criteria.

STUDY DESIGN

This is a prospective single-blind single-centre study of patients newly referred to the Memory Clinic.

METHOD

The study cohort consists of older persons with no significant physical disability referred for assessment of subjective or objective cognitive decline to the Memory Service. The participants will undergo an occupational therapy (OT) clinic assessment which includes scoring the Australian Modified Lawton’s IADL scale and Timed Up and Go (TUG)assessment. The assessment will consist of a comprehensive interview of usual daily living activities and performance of several ADL based tasks. The carer is invited to be part of the interview. They will be provided with an information sheet on the research project. The occupational therapist is blinded to the diagnosis because the assessment occurs prior to any diagnosis by medical clinicians.

The OT assessment is followed by medical assessment including cognitive assessment in the outpatient Memory Clinic. This will include completion of a Mini Mental State Examination (MMSE), according to the standard procedure. The final cognitive diagnosis is determined by the Geriatrician, according to DSM V criteria.

The Australian Modified Lawton’s IADL scale scores are then analysed to determine the range of scores on the scale stratified by the three diagnostic groups of NC, MCI and D and to determine the between-group cut off points.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 72154 0
Mrs Vera Riley
Address 72154 0
Occupational Therapy Department
Sir Charles Gairdner Hospital
C Block, Hospital Avenue
Nedlands WA 6009
Country 72154 0
Australia
Phone 72154 0
+61 8 6457 2855
Fax 72154 0
Email 72154 0
Vera.Riley@health.wa.gov.au
Contact person for public queries
Name 72155 0
Mrs Kristie Harper
Address 72155 0
Occupational Therapy Department
Sir Charles Gairdner Hospital
C Block, Hospital Avenue
Nedlands WA 6009
Country 72155 0
Australia
Phone 72155 0
+61 8 6457 2855
Fax 72155 0
Email 72155 0
Kristie.Harper@health.wa.gov.au
Contact person for scientific queries
Name 72156 0
Mrs Kristie Harper
Address 72156 0
Occupational Therapy Department
Sir Charles Gairdner Hospital
C Block, Hospital Avenue
Nedlands WA 6009
Country 72156 0
Australia
Phone 72156 0
+61 8 6457 2855
Fax 72156 0
Email 72156 0
Kristie.Harper@health.wa.gov.au

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary