The Hawthorne Effect: a randomised, controlled trial
2007

The Hawthorne Effect in Dementia Trials

Sample size: 176 publication 10 minutes Evidence: moderate

Author Information

Author(s): Rob McCarney, James Warner, Steve Iliffe, Robbert van Haselen, Mark Griffin, Peter Fisher

Primary Institution: Imperial College London

Hypothesis

Does intensive follow-up in a placebo-controlled trial of Ginkgo biloba improve cognitive functioning and quality of life compared to minimal follow-up?

Conclusion

More intensive follow-up resulted in better cognitive outcomes compared to minimal follow-up in participants with mild-moderate dementia.

Supporting Evidence

  • Intensive follow-up improved cognitive functioning as measured by the ADAS-Cog.
  • Quality of life ratings were worse in the intensive follow-up group.
  • The study was conducted in a community setting with participants aged 55 and over.
  • Recruitment was primarily through general practices.
  • Participants were randomly assigned to follow-up groups to assess the Hawthorne Effect.

Takeaway

This study looked at how different types of follow-up affect people in a dementia trial, finding that more check-ins helped with thinking skills.

Methodology

Participants were randomly assigned to either intensive or minimal follow-up in a trial assessing Ginkgo biloba for dementia.

Potential Biases

Participants and researchers were not blinded to the follow-up group, which could introduce bias.

Limitations

The study focused on a specific group of dementia patients, which may limit the generalizability of the findings.

Participant Demographics

Participants were mainly elderly individuals with mild-moderate dementia, with a mean age of approximately 79.5 years.

Statistical Information

P-Value

0.037

Confidence Interval

95%CI -3.914, -0.121

Statistical Significance

p<0.05

Digital Object Identifier (DOI)

10.1186/1471-2288-7-30

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