In BMC Psychiatry a recent paper by Manzoni and colleagues looks at studies of relaxation training. Anxiety causes a huge burden and it’s estimated that there is just under a 17% lifetime prevalence of anxiety disorders globally. One of the approaches to treating anxiety is to use an anxiety management strategy which ranges from progressive muscle relaxation exercises through to meditation. The authors looked at studies involving these types of anxiety management techniques. They included Randomised Control Trials (RCT’s) and studies without controls. This is a different approach from that used in the Cochrane register which includes only RCT’s. However, one of the difficulties with meta-analyses of RCT’s is that there often aren’t enough of these to draw satisfactory conclusions.
The meta-analysis included results from 1005 people in 19 studies. When controls were present the researchers used calculated a statistic known as the Cohen’s D to estimate the difference between those undergoing treatment and controls. In studies without controls they compared outcome with the baseline measurements. Only the results of the Hospital Anxiety and Depression Scale, the Beck Anxiety Inventory and the Spielberger’s State-Trait Anxiety Inventory were included in the final analysis.
The researchers found that the overall Cohen’s D for relaxation training was 0.57 which is interpreted as being a medium-high score. They also used a Failsafe N calculation to estimate the effects of any studies that weren’t included in their study – for instance if they were unpublished. However the Failsafe N has been criticised as estimating in the direction of the study results. They estimated that a further 118 studies without significant findings would be required to nullify the results found in this meta-analysis.
The authors concluded that using a single approach was better than using multiple relaxation techniques. Although they found big differences between individual approaches they concluded that applied relaxation and meditation had big effect sizes both within and between groups whilst progressive relaxation had the biggest effect within groups. They also found that as people got older the effects of relaxation training decreased.
(STT = 1)
The comments made here represent the opinions of the author and do not represent the profession or any body/organisation. The comments made here are not meant as a source of medical advice and those seeking medical advice are advised to consult with their own doctor.