title: Quasi-experimental study designs series-paper 5: a checklist for classifying studies evaluating the effects on health interventions-a taxonomy without labels.
abstract: OBJECTIVE
  The aim of the study was to extend a previously published checklist of study design features to include study designs often used by health systems researchers and economists. Our intention is to help review authors in any field to set eligibility criteria for studies to include in a systematic review that relate directly to the intrinsic strength of the studies in inferring causality. We also seek to clarify key equivalences and differences in terminology used by different research communities.
  
  
  METHODS
  Expert consensus meeting.
  
  
  RESULTS
  The checklist comprises seven questions, each with a list of response items, addressing: clustering of an intervention as an aspect of allocation or due to the intrinsic nature of the delivery of the intervention; for whom, and when, outcome data are available; how the intervention effect was estimated; the principle underlying control for confounding; how groups were formed; the features of a study carried out after it was designed; and the variables measured before intervention.
  
  
  CONCLUSIONS
  The checklist clarifies the basis of credible quasi-experimental studies, reconciling different terminology used in different fields of investigation and facilitating communications across research communities. By applying the checklist, review authors' attention is also directed to the assumptions underpinning the methods for inferring causality.
authors.affiliation: Clinical Trials and Evaluation Unit, School of Clinical Sciences, University of Bristol, Level 7 Queen's Building, Bristol Royal Infirmary, Bristol BS2 8HW, UK. Electronic address: Barney.Reeves@bristol.ac.uk.
authors.forename: Barnaby C
authors.initials: BC
authors.lastname: Reeves
authors.affiliation: Department of Epidemiology and Community Medicine, Faculty of Medicine, University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, Ontario, Canada K1Y 4W7.
authors.forename: George A
authors.initials: GA
authors.lastname: Wells
authors.affiliation: International Initiative for Impact Evaluation (3ie), 202-203, Rectangle One, D-4, Saket District Centre, New Delhi, 110017, India.
authors.forename: Hugh
authors.initials: H
authors.lastname: Waddington
mesh_terms: D057189:Checklist; D003695:Delivery of Health Care; D004467:Economics; D005069:Evaluation Studies as Topic; D006302:Health Services Research; D006801:Humans; D065228:Non-Randomized Controlled Trials as Topic / Q000145:classification*; D012107:Research Design
keywords: Evaluation; Health care; Health system; Nonrandomized; Quasi-experimental; Study design