Being mindful of mindfulness interventions in cancer: A systematic review of intervention reporting and study methodology

OBJECTIVES: While mindfulness-based stress reduction (MBSR) and mindfulness-based cognitive therapy (MBCT) have demonstrated efficacy in clinical populations, the potential therapeutic benefit of mindfulness in the context of cancer is less clear. The aim of this review was to critically appraise mindfulness intervention reporting and study methodology. METHODS: Studies using randomized control trial design and/or a control arm were included. PubMed, Medline, PsycINFO, CINAHL, and Embase databases between January 1999 and April 2017 were searched. Studies were assessed on (1) reported theoretical framework, (2) intervention description, and (3) justification of modifications to standardized MBSR/MBCT. The overall quality of study design and research methodology were also assessed. RESULTS: Of 30 studies identified, none adhered to MBSR. Modified versions of MBSR were reported in 19 studies. Five studies reported variants of MBCT, 1 used a combination of MBSR/MBCT, and 5 inadequately documented the intervention/ theoretical framework. Overall, component and timeline modifications were poorly documented and justified. Mean intervention contact time was less than standardized MBSR/MBCT protocols. Target outcomes were poorly justified, and 12 studies failed to identify a primary aim, reporting multiple outcomes. Only 9 of 15 studies recruiting clinical populations included clinical cutoffs, and an active therapeutic control was included in 4 studies. CONCLUSIONS: Mindfulness is increasingly considered a standard therapy in psycho-oncology. While many studies proclaim benefits, considerable variability, modification to standardized protocols, and claims of benefit often reflect decreases in sub-clinical supportive care symptomology rather than therapeutic relief of clinically significant psychological disorders.