National Institute for Health Research (NIHR)
Raine R, Fitzpatrick R, Barratt H, Bevan G, Black N, Boaden R, et al. Challenges, solutions and future directions in the evaluation of service innovations in health care and public health. Health Serv Deliv Res 2016;4(16)
Policies and interventions in the health care system may have a wide range of effects on multiple patient outcomes and operate through many clinical processes. This presents a challenge for their evaluation, especially when the effect on any one patient is small. This essay explores the nature of the health care system and discuss how the empirical evidence produced within it relates to the underlying processes governing patient outcomes.