Mindfulness-Based Cognitive Therapy for Life (MBCT-L) Versus Stress Reduction Psychoeducation (SRP) for the Improvement of Mental Well-Being in Health Care and Other Public Sector Staff: Protocol for the Well at Work Randomized Controlled Trial - Elena Nixon; Shireen Patel; Priya Patel; James Roe; Neil Nixon; Tim Sweeney; Paul Bernard; Clara Strauss; Michael P Craven; Sam Malins; Rob Goodwin; Laurence Astill Wright; et al. (JMIR Research Protocols)