Open Access Open Badges Study protocol

Evidence-based care of older people with suspected cognitive impairment in general practice: protocol for the IRIS cluster randomised trial

Joanne E McKenzie1*, Simon D French12, Denise A O’Connor1, Duncan S Mortimer3, Colette J Browning4, Grant M Russell4, Jeremy M Grimshaw5, Martin P Eccles6, Jill J Francis7, Susan Michie8, Kerry Murphy1, Fiona Kossenas1, Sally E Green1 and IRIS trial group

Author Affiliations

1 School of Public Health and Preventive Medicine, Monash University, The Alfred Centre, 99 Commercial Road, Melbourne, Australia

2 Centre for Health, Exercise and Sports Medicine, The University of Melbourne, Alan Gilbert Building, Level 7, 161 Barry St, Carlton, Melbourne, Australia

3 Centre for Health Economics, Faculty of Business and Economics, Monash University, Level 2, Building 75, Monash University Clayton, Melbourne, Australia

4 School of Primary Health Care, Monash University, Building 1, 270 Ferntree Gully Road, Notting Hill, Melbourne, Australia

5 Clinical Epidemiology Program, Ottawa Health Research Institute, Ottawa, Canada; Department of Medicine, University of Ottawa, The Ottawa Hospital (General Campus), 501 Smyth Road, Ottawa, Canada

6 Institute of Health and Society, Newcastle University, Baddiley Clark Building, Richardson Road, Newcastle upon Tyne, UK

7 School of Health Sciences, City University London, Tait Building, Northampton Square, London, UK

8 Department of Psychology, University College London, 1-19 Torrington Place, London, UK

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Implementation Science 2013, 8:91  doi:10.1186/1748-5908-8-91

Published: 19 August 2013



Dementia is a common and complex condition. Evidence-based guidelines for the management of people with dementia in general practice exist; however, detection, diagnosis and disclosure of dementia have been identified as potential evidence-practice gaps. Interventions to implement guidelines into practice have had varying success. The use of theory in designing implementation interventions has been limited, but is advocated because of its potential to yield more effective interventions and aid understanding of factors modifying the magnitude of intervention effects across trials. This protocol describes methods of a randomised trial that tests a theory-informed implementation intervention that, if effective, may provide benefits for patients with dementia and their carers.


This trial aims to estimate the effectiveness of a theory-informed intervention to increase GPs’ (in Victoria, Australia) adherence to a clinical guideline for the detection, diagnosis, and management of dementia in general practice, compared with providing GPs with a printed copy of the guideline. Primary objectives include testing if the intervention is effective in increasing the percentage of patients with suspected cognitive impairment who receive care consistent with two key guideline recommendations: receipt of a i) formal cognitive assessment, and ii) depression assessment using a validated scale (primary outcomes for the trial).


The design is a parallel cluster randomised trial, with clusters being general practices. We aim to recruit 60 practices per group. Practices will be randomised to the intervention and control groups using restricted randomisation. Patients meeting the inclusion criteria, and GPs’ detection and diagnosis behaviours directed toward these patients, will be identified and measured via an electronic search of the medical records nine months after the start of the intervention. Practitioners in the control group will receive a printed copy of the guideline. In addition to receipt of the printed guideline, practitioners in the intervention group will be invited to participate in an interactive, opinion leader-led, educational face-to-face workshop. The theory-informed intervention aims to address identified barriers to and enablers of implementation of recommendations. Researchers responsible for identifying the cohort of patients with suspected cognitive impairment, and their detection and diagnosis outcomes, will be blind to group allocation.

Trial registration

Australian New Zealand Clinical Trials Registry: ACTRN12611001032943 (date registered 28 September, 2011).