title: Developing and Optimising the Use of Logic Models in Systematic Reviews: Exploring Practice and Good Practice in the Use of Programme Theory in Reviews.
abstract: BACKGROUND
  Logic models are becoming an increasingly common feature of systematic reviews, as is the use of programme theory more generally in systematic reviewing. Logic models offer a framework to help reviewers to 'think' conceptually at various points during the review, and can be a useful tool in defining study inclusion and exclusion criteria, guiding the search strategy, identifying relevant outcomes, identifying mediating and moderating factors, and communicating review findings.
  
  
  RESULTS
  In this paper we critique the use of logic models in systematic reviews and protocols drawn from two databases representing reviews of health interventions and international development interventions. Programme theory featured only in a minority of the reviews and protocols included. Despite drawing from different disciplinary traditions, reviews and protocols from both sources shared several limitations in their use of logic models and theories of change, and these were used almost unanimously to solely depict pictorially the way in which the intervention worked. Logic models and theories of change were consequently rarely used to communicate the findings of the review.
  
  
  CONCLUSIONS
  Logic models have the potential to be an aid integral throughout the systematic reviewing process. The absence of good practice around their use and development may be one reason for the apparent limited utility of logic models in many existing systematic reviews. These concerns are addressed in the second half of this paper, where we offer a set of principles in the use of logic models and an example of how we constructed a logic model for a review of school-based asthma interventions.
authors.affiliation: Evidence for Policy and Practice Information and Co-ordinating Centre (EPPI-Centre), UCL Institute of Education, University College London, London, United Kingdom.
authors.forename: Dylan
authors.initials: D
authors.lastname: Kneale
authors.affiliation: Evidence for Policy and Practice Information and Co-ordinating Centre (EPPI-Centre), UCL Institute of Education, University College London, London, United Kingdom.
authors.forename: James
authors.initials: J
authors.lastname: Thomas
authors.affiliation: Centre for Paediatrics, Blizard Institute, Queen Mary University of London, London, United Kingdom.
authors.forename: Katherine
authors.initials: K
authors.lastname: Harris
mesh_terms: D001249:Asthma / Q000628:therapy; D006801:Humans; D008128:Logic; D008962:Models, Theoretical; D012196:Review Literature as Topic