McCarney, R;
Warner, J;
Iliffe, S;
van Haselen, R;
Griffin, M;
Fisher, P;
(2007)
The Hawthorne Effect: a randomised, controlled trial.
BMC MED RES METHODOL
, 7
, Article 30. 10.1186/1471-2288-7-30.
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Abstract
Background: The 'Hawthorne Effect' may be an important factor affecting the generalisability of clinical research to routine practice, but has been little studied. Hawthorne Effects have been reported in previous clinical trials in dementia but to our knowledge, no attempt has been made to quantify them. Our aim was to compare minimal follow- up to intensive follow-up in participants in a placebo controlled trial of Ginkgo biloba for treating mild-moderate dementia.Methods: Participants in a dementia trial were randomised to intensive follow- up (with comprehensive assessment visits at baseline and two, four and six months post randomisation) or minimal follow-up (with an abbreviated assessment at baseline and a full assessment at six months). Our primary outcomes were cognitive functioning (ADAS-Cog) and participant and carer-rated quality of life (QOL-AD).Results: We recruited 176 participants, mainly through general practices. The main analysis was based on Intention to treat (ITT), with available data. In the ANCOVA model with baseline score as a co- variate, follow-up group had a significant effect on outcome at six months on the ADAS-Cog score (n = 140; mean difference = -2.018; 95% Cl -3.914, -0.121; p = 0.037 favouring the intensive follow-up group), and on participant- rated quality of life score (n = 142; mean difference = -1.382; 95% Cl -2.642, -0.122; p = 0.032 favouring minimal follow-up group). There was no significant difference on carer quality of life.Conclusion: We found that more intensive follow-up of individuals in a placebo-controlled clinical trial of Ginkgo biloba for treating mild-moderate dementia resulted in a better outcome than minimal follow-up, as measured by their cognitive functioning.
| Type: | Article |
|---|---|
| Title: | The Hawthorne Effect: a randomised, controlled trial |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1186/1471-2288-7-30 |
| Publisher version: | http://www.biomedcentral.com/1471-2288/7/30 |
| Language: | English |
| Additional information: | © 2007 McCarney et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. |
| Keywords: | PLACEBO-CONTROLLED TRIAL, DISEASE ASSESSMENT SCALE, ALZHEIMERS-DISEASE, CLINICAL-TRIALS, DOUBLE-BLIND, DONEPEZIL, EFFICACY, SAFETY, TERM, US |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Population Health Sciences > Institute of Epidemiology and Health UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Population Health Sciences > Institute of Epidemiology and Health > Primary Care and Population Health |
| URI: | https://discovery.ucl.ac.uk/id/eprint/63410 |
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