ABSTRACT & COMMENTARY
Mindfulness-Based Interventions: Do They Decrease Anxiety in Cancer Patients? A systematic review and meta-analysis
Poorvi Shah, DO
REFERENCE
PRIMARY OUTCOME MEASURES
STUDY OBJECTIVE
KEY FINDINGS
Oberoi S, Yang J, Woodgate RL, et al. Association of mindfulness-based interventions with anxiety severity in adults with cancer: a systematic review and meta-analysis. JAMA Netw Open. 2020;3(8):e2012598. The aim of this review was to determine whether mindfulness-based interventions (MBIs) improve anxiety in cancer patients. STUDY DESIGN
The researchers conducted a systematic review and meta-analysis of clinical trials “extracted from MEDLINE, Embase, Cochrane Central Register of Controlled Trials, CINAHL, PsycINFO, and SCOPUS from database inception to May 2019.” All trials were randomized to MBI versus a control group, which could be a sham treatment, no intervention, waitlisted participants, or usual care. Inclusion criteria included adults and children with cancer or who were receiving stem cell treatment for cancer. Exclusion criteria included “observational, quasi-randomized, crossover, or cluster-randomized trial designs and trials that did not report any outcomes of interest to this review.” There were no languages excluded from the data extraction. Interventions that included physical movement, such as yoga, qigong, and tai chi, were excluded. PARTICIPANTS
The 28 studies included in the meta-analysis involved a total of 3,053 individuals. All participants were adults, since none of the trials with subjects aged less than 18 years met review criteria. Participants could be in active treatment or posttreatment, with some receiving MBIs both during and after their treatments. STUDY PARAMETERS
An initial search found 5,686 citations. After blinded screening and independent review by 2 of this publication’s authors, 27 trials ultimately met the review criteria. The researchers added another study, which they found by hand, for a total of 28 trials.
The primary outcome measure was the severity of short-term anxiety up to 1 month post MBI. Secondary outcome measures included anxiety, depression, and quality of life in the medium term (1–6 months) and long term (6–12 months) after MBI. The most common MBI used in the trials included mindfulness-based stress reduction (MBSR; 13 trials, 46.4%) and mindfulness-based cognitive therapy (MBCT; 6 trials, 21.4%). The median duration of MBIs was 8 weeks. There were 12 different anxiety scales used in the trials, with Hospital Anxiety and Depression Scale A (HADS-A; 5 trials) and State-Trait Anxiety Inventory (STAI; 5 trials) being the most common. Breast cancer was by far the most well-represented cancer type in this review. Twelve trials (42.8%) looked at MBIs and breast cancer exclusively. Eleven recruited participants with various cancer types, and of these, breast cancer was still the most prevalent cancer in 10 of the studies. MBIs significantly reduced short-term (0–1 month) anxiety (23 trials; 2,339 participants; SMD, −0.51; 95% CI, −0.70 to −0.33; I 2=76%). Reduction in short-term anxiety was evident when HADS-A or the STAI scale was used in independent statistical analysis of each. MBIs also reduced the severity of medium-term (>1–6 months) anxiety (9 trials; 965 participants; SMD, −0.43; 95% CI, −0.68 to −0.18; I 2=66%). MBIs were not associated with long-term (>6 months–1 year) reduction in anxiety (2 trials; 403 participants; SMD, −0.02; 95% CI, −0.38 to 0.34; I 2= 68%). Additional findings demonstrated a reduction in depression in the short term (19 trials; 1,874 participants; SMD, −0.73; 95% CI, −1.00 to −0.46; I 2=86%) and medium term (8 trials; 891 participants; SMD, −0.85; 95% CI, −1.35 to −0.35; I 2= 91%), but not in the long term (2 trials; 349 participants; SMD, −0.96; 95% CI, −2.38 to 0.46; I 2= 97%). MBIs were also associated with improvement in overall health-related quality-of-life (HRQOL) scores in both the short term (9 trials; 1,108 participants; SMD, 0.51; 95% CI, 0.20 to 0.82; I 2=82%) and medium term (5 trials; 771 participants; SMD, 0.29; 95% CI, 0.06 to 0.52; I 2=57%) The single trial that tracked HRQOL long term did not show any benefit (1 trial; 153 participants; WMD, 0.78; 95% CI, −5.98 to 7.54).
18 ©2020 NATURAL MEDICINE JOURNAL. ALL RIGHTS RESERVED. NMJ, OCTOBER 2020 SUPPLEMENT—VOL. 12, NO. 101 (SUPPL)
