Within the woodland October is a month of themes. Many of you will be familiar with #Stoptober, which always helps any elves who sneak round the the back of the woodshed, to give up smoking. You may be less aware of our #MindfulnessMonday activities that will be sprinkled across the month; showcasing the potential benefits that mindfulness can have on our mental well-being.

Psychological distress is common among breast cancer patients. It has been reported that the frequency of intrusive thoughts in the minds of breast cancer survivors is related to psychological distress. The prevalence of clinical depression in breast cancer patients ranges between 11% and 20% and 16% for anxiety disorder.

Mindfulness-based stress reduction (MBSR) is a psychoeducational training initially developed by Kabat-Zinn for chronic pain patients and stress-related conditions. It is a group programme commonly conducted for 8 weeks, with weekly 2.5hr sessions and one full retreat day. The participants are given a CD containing instructions for home practice for 45 min per day, 6 days a week. The main components of MBSR are the body scan, breathing meditation, walking meditation, mindful movement and psychoeducation. The participants learn effective ways of handling moods and emotions by becoming aware, from moment to moment, of thoughts, feelings, bodily sensations and the world around them

This meta-analysis by Zainal et al was published in Psycho-oncology in July of this year, it investigates the efficacy of MBSR on stress, depression and anxiety in breast cancer survivors.

Methods

The authors completed an extensive systematic electronic review and 33 studies of the effects of MBSR on mental health in patients with cancer (including breast cancer) were found.

To reinforce validity, two independent investigators studied the papers coming to a consensus on decisions of which studies to include.

Inclusion criteria were:

1. use of MBSR as the intervention
2. breast cancer patients
3. trials looking at the effects on mental health (stress, depression or anxiety)
4. sufficient data were reported for the calculation of standardised effect size. Studies on mixed cancer participants and/or mixed interventions were excluded.
5. Multiple publications were excluded to avoid double counting

Nine studies were identified which included two randomised controlled trials (RCTs), one quasi-experimental case–control study and six one-group, pre-intervention and post intervention studies. All studies were completed in USA or Canada.

Results

Effect size was calculated for the studies obtained. This is a measurement of the strength of the relationship between two variables of studied populations. To interpret the resulting number, they used a general guide developed by Cohen: <0.1=trivial effect, 0.1–0.3=small effect, 0.3–0.5=moderate effect and 0.5=large difference effect.

Heterogeneity was also examined to ensure similar commodities were being compared; the lower the  heterogeneity the better.

• Eight studies (N= 307) included a measure of stress; overall effect size on stress was 0.710 (d = 0.368 for randomised study, d = 0.757 for non-randomised studies). Heterogeneity low
• Seven studies (N= 392) included a measure of depression, overall effect size on depression was 0.575 (d = 0.422 for the RCTs, d = 0.628 for the non-randomised studies). Heterogeneity absent
• Four studies (N= 166) included a measure of anxiety, overall effect size on anxiety was 0.733 (d = 0.488 for one RCT, d = 0.816 for the non-randomised studies). Heterogeneity moderate

Conclusions

we have found a positive, moderate-to-large effect size of MBSR in reducing perceived stress, depression and anxiety in women with breast cancer

As  you will have seen the effect size for the non-randomised studies was much higher than randomized trials. Non randomized trials are at risk of selection bias, where individuals seeking help are more likely to participate in the intervention with positive expectations of it and so the reliability of these results is not clear.

Another possible limitation was the probable non-inclusion of some studies because of inadequate data reported however, publication bias assessment estimated two missing studies on the right side of the funnel plot, indicating that the effect size is even larger if these are taken into account for stress. Similarly in common with most reviews and meta-analyses, methodological inconsistency, poor data reporting, inconsistency in the qualifications of the trainers/ facilitators and inadequate statistical power are among other limitations of this meta-analysis.

The levels of distress, depression and anxiety at baseline among the participants in included studies were high and had decreased significantly post-intervention. Low initial scores of perceived stress were however not significantly different post-MBSR.

Summary

Of the studies available Zainal et al did find a positive, moderate-to-large effect size of MBSR in reducing perceived stress, depression and anxiety in women with breast cancer.

It is clear however that there is a need for adequately powered RCTs, to be carried out not only to examine the impact of MBSR on negative aspects of mental health but also to measure the positive outcomes of MBSR in women with breast cancer such as enhancement of vitality, resilience, self  confidence and positive mood.

The use of MBSR however is not just limited to patients with breast cancer; here is a short video of how you can use it within your day to day life. It may take some practice, but like any skill the more you do it, the better you get. This video is 4 minutes long…..go on, give it a go.

Links

Zainal NZ, Booth S, Huppert FA. The efficacy of mindfulness-based stress reduction on mental health of breast cancer patients: a meta-analysis. Psycho-Oncology 2013; 22(7): 1457-1465. [PubMed abstract]