Patient and public involvement (PPI) in prisons: the involvement of people living in prison in the research process - a systematic scoping review.

Given the very high risk of bias arising from the available 'evaluations', it was not possible to derive firm conclusions about the effectiveness of PLiP involvement in the research process. In addition, given the state of the evidence base, it was felt that a systematic review would not be feasible until more evaluations were undertaken using a range of methodologies to develop the field further.