This recent systematic review continues the call for increased scientific rigour including 'using active control conditions, larger sample sizes, longer follow-up assessment, treatment fidelity assessment, and reporting of instructor training and intent-to-treat (ITT) analyses.'
(1) PLoS One. 2017 Oct 31;12(10):e0187298. doi: 10.1371/journal.pone.0187298. eCollection 2017. Is mindfulness research methodology improving over time? A systematic review. Goldberg SB, Tucker RP, Greene PA, Simpson TL, Kearney DJ, Davidson RJ.