Take the money and run: the challenges of designing and evaluating financial incentives in healthcare; Comment on "Paying for performance in healthcare organisations".

Many countries are turning their attention to the use of explicit financial incentives to drive desired improvements in healthcare performance. However, we have only a weak evidence-base to inform policy in this area. The research challenge is to generate robust evidence on what financial incentives work, under what circumstances, for whom and with what intended and unintended consequences.