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The use of global positional satellite location in dementia: a feasibility study for a randomised controlled trial

Heather Milne1, Marjon van der Pol2, Lucy McCloughan1, Janet Hanley34, Gillian Mead5, John Starr5, Aziz Sheikh167 and Brian McKinstry13*

Author Affiliations

1 E-Health Group, Centre for Population Health Sciences, The University of Edinburgh, Telescot, Room 216b, Doorway 3, Medical School Teviot Place, Edinburgh EH8 9AG, UK

2 Health Economics Research Unit, The University of Aberdeen, Aberdeen, UK

3 The Edinburgh Health Services Research Unit, Edinburgh, UK

4 Department of Nursing, Edinburgh Napier University, Edinburgh, UK

5 Department of Geriatric Medicine, The University of Edinburgh, Edinburgh, UK

6 Division of General Internal Medicine and Primary Care, Brigham and Women’s Hospital, Brigham, USA

7 Department of Medicine, Harvard Medical School, Boston, USA

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BMC Psychiatry 2014, 14:160  doi:10.1186/1471-244X-14-160

Published: 30 May 2014



Getting lost outside is stressful for people with dementia and their caregivers and a leading cause of long-term institutionalisation. Although Global Positional Satellite (GPS) location has been promoted to facilitate safe walking, reduce caregivers’ anxiety and enable people with dementia to remain at home, there is little high quality evidence about its acceptability, effectiveness or cost-effectiveness. This observational study explored the feasibility of recruiting and retaining participants, and the acceptability of outcome measures, to inform decisions about the feasibility of a randomised controlled trial (RCT).


People with dementia who had been provided with GPS devices by local social-care services and their caregivers were invited to participate in this study. We undertook interviews with people with dementia, caregivers and professionals to explore the perceived utility and challenges of GPS location, and assessed quality of life (QoL) and mental health. We piloted three methods of calculating resource use: caregiver diary; bi-monthly telephone questionnaires; and interrogation of health and social care records. We asked caregivers to estimate the time spent searching if participants became lost before and whilst using GPS.


Twenty people were offered GPS locations services by social-care services during the 8-month recruitment period. Of these, 14 agreed to be referred to the research team, 12 of these participated and provided data. Eight people with dementia and 12 caregivers were interviewed. Most participants and professionals were very positive about using GPS. Only one person completed a diary. Resource use, anxiety and depression and QoL questionnaires were considered difficult and were therefore declined by some on follow-up. Social care records were time consuming to search and contained many omissions. Caregivers estimated that GPS reduced searching time although the accuracy of this was not objectively verified.


Our data suggest that a RCT will face challenges not least that widespread enthusiasm for GPS among social-care staff may challenge recruitment and its ready availability may risk contamination of controls. Potential primary outcomes of a RCT should not rely on caregivers’ recall or questionnaire completion. Time spent searching (if this could be accurately captured) and days until long-term admission are potentially suitable outcomes.

Dementia; Feasibility study; Global positional satellite location; Wandering