[grattperret]

While it may be the case,(and l hope it is so) l would imagine that those who meditate are more likely to improve the quality of their lives,while sick. But for 'ordinary' folk this may be the extent of it.
Those that don't meditate,may have no training in controlling their mind,so are more likely to be subject to what ever aspect of their illness is mental.
I would suggest that sickness is not 'all in the mind'. But how we deal with it certainly is.