Many of our older readers will remember tales of the Great Elf Mother running miles every day, o’er hills and vales, to bring the very latest evidence-based research to us younger elves at the breakfast table. It was she who inspired our National Elf Service, and I’m delighted to say that she’s still going strong and as bright as a button at over 600 years old. Physical and mental exercise has certainly kept her healthy!
A new systematic review published today by the Cochrane Dementia and Cognitive Improvement Group brings together the findings from RCTs that investigate the impact that exercise can have on older people with dementia.
The review was originally published in 2008 and this new version includes significantly more studies that have been published in the intervening years, although the quality of the included research is still far from perfect.
The review set out to answer the following questions:
- Do exercise programs for older people with dementia improve cognition, activities of daily living (ADLs), challenging behaviour, depression, and mortality in older people with dementia?
- Do exercise programs for older people with dementia have an indirect impact on family caregivers’ burden, quality of life, and mortality?
- Do exercise programs for older people with dementia reduce the use of healthcare services (e.g. visits to the emergency department) by participants and their family caregivers?
The reviewers led by Professor Dorothy Forbes from the University of Alberta searched the ALOIS open access register of dementia studies for randomised controlled trials in which older people, diagnosed with dementia, were allocated either to exercise programs or to control groups (usual care or social contact/activities) with the aim of improving cognition, activities of daily living (ADLs), behaviour, depression and mortality.
As usual with a Cochrane review, two independent authors retrieved articles for inclusion, assessed methodological quality and extracted data. They used a fixed effect model to synthesise the data, unless there was substantial heterogeneity where they used a random effect model.
They found 16 RCTs that met their inclusion criteria, including a total of 937 participants.
They measured heterogeneity using the quantity I2 (Higgins, 2003).
- Looking at the 16 included RCTs:
- 8 RCTs examined cognitive functioning
- 6 RCTs examined ADLs (feeding, bathing, dressing, homemaking, leisure etc.)
- 6 RCTs examined depression
- 4 RCTs examined challenging behaviour
- Only 2 RCTs included people living at home
- Cognitive functioning:
- The meta-analysis found that exercise programs might have a signiﬁcant impact on improving cognitive functioning (8 trials, 329 participants; SMD 0.55, 95% conﬁdence interval (CI) 0.02 to 1.09). However, these results showed significant heterogeneity between trials (I2 value 80%)
- The reviewers removed 1 outlier trial and this reduced the heterogeneity (I2 value 68%), but left them with a result that was no longer statistically significant (7 trials, 308 participants; SMD 0.31, 95% CI -0.11 to 0.74)
- Activities of daily living (ADLs)
- The analysis showed that exercise programs may have a significant impact on the ability of people with dementia to perform ADLs (6 studies, 289 participants SMD 0.68, 95% CI 0.08 to 1.27), but again the heterogeneity was high (I2 value 77%)
- No significant effect was found for exercise on depression or challenging behaviour
The Cochrane reviewers concluded that:
There is promising evidence that exercise programs can have a signiﬁcant impact in improving ability to perform ADLs and possibly in improving cognition in people with dementia, although some caution is advised in interpreting these ﬁndings. The programs revealed no signiﬁcant effect on challenging behaviours or depression. There was little or no evidence regarding the remaining outcomes of interest.
This review shows that a fair amount of research is being conducted in this area. The number of included trials has increased 4-fold in the last 5 years (4 in 2008 to 16 in 2013), but the fact remains that these studies are a heterogeneous group and it is difficult to make any clear recommendations by pooling them.
The reviewers state that exercise can help with ADLs and may possibly help with cognitive function, but these statements are based on pooling diverse studies and even then the confidence intervals around the results are tickling zero. It’s hardly convincing evidence. Promising yes, but the jury is still out.
In the woodland, we like to have a bit more certainty before we make recommendations, so we’re looking out for the next update of this review, in the hope that it will bring some more compelling results.
Of course, exercise is just about the most fun you can have, whether you’re 6 or 600, so take a leaf out of the Elf Mother’s book and get yourself out and about this week for some heart pumping fun.
Forbes D, Thiessen EJ, Blake CM, Forbes SC, Forbes S. Exercise programs for people with dementia. Cochrane Database of Systematic Reviews 2013, Issue 11. Art. No.: CD006489. DOI: 10.1002/14651858.CD006489.pub3.
Higgins JPT ,Thompson SG ,Deeks JJ ,Altman DG. Measuring inconsistency in meta-analyses. BMJ 2003;327:557