Making the most of natural experiments: What can studies of the withdrawal of public health interventions offer?

Craig, P. , Gibson, M. , Campbell, M. , Popham, F. and Katikireddi, S. V. (2018) Making the most of natural experiments: What can studies of the withdrawal of public health interventions offer? Preventive Medicine, 108, pp. 17-22. (doi: 10.1016/j.ypmed.2017.12.025) (PMID:29288780) (PMCID:PMC6711756)

154639.pdf - Published Version
Available under License Creative Commons Attribution.



Many interventions that may have large impacts on health and health inequalities, such as social and public health policies and health system reforms, are not amenable to evaluation using randomised controlled trials. The United Kingdom Medical Research Council's guidance on the evaluation of natural experiments draws attention to the need for ingenuity to identify interventions which can be robustly studied as they occur, and without experimental manipulation. Studies of intervention withdrawal may usefully widen the range of interventions that can be evaluated, allowing some interventions and policies, such as those that have developed piecemeal over a long period, to be evaluated for the first time. In particular, sudden removal may allow a more robust assessment of an intervention's long-term impact by minimising ‘learning effects’. Interpreting changes that follow withdrawal as evidence of the impact of an intervention assumes that the effect is reversible and this assumption must be carefully justified. Otherwise, withdrawal-based studies suffer similar threats to validity as intervention studies. These threats should be addressed using recognised approaches, including appropriate choice of comparators, detailed understanding of the change processes at work, careful specification of research questions, and the use of falsification tests and other methods for strengthening causal attribution. Evaluating intervention withdrawal provides opportunities to answer important questions about effectiveness of population health interventions, and to study the social determinants of health. Researchers, policymakers and practitioners should be alert to the opportunities provided by the withdrawal of interventions, but also aware of the pitfalls.

Item Type:Articles
Glasgow Author(s) Enlighten ID:Katikireddi, Professor Vittal and Craig, Professor Peter and Popham, Dr Frank and Gibson, Dr Marcia and Campbell, Ms Mhairi
Authors: Craig, P., Gibson, M., Campbell, M., Popham, F., and Katikireddi, S. V.
College/School:College of Medical Veterinary and Life Sciences > School of Health & Wellbeing > MRC/CSO SPHSU
Journal Name:Preventive Medicine
ISSN (Online):1096-0260
Published Online:27 December 2017
Copyright Holders:Copyright © 2018 The Authors
First Published:First published in Preventive Medicine 108: 17-22
Publisher Policy:Reproduced under a Creative Commons License

University Staff: Request a correction | Enlighten Editors: Update this record

Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
727671Informing Healthy Public PolicyPeter CraigMedical Research Council (MRC)MC_UU_12017/15HW - MRC/CSO Social and Public Health Sciences Unit
727651Measuring and Analysing Socioeconomic Inequalities in HealthAlastair LeylandMedical Research Council (MRC)MC_UU_12017/13HW - MRC/CSO Social and Public Health Sciences Unit
699162Understanding the impacts of welfare policy on health: A novel data linkage studySrinivasa KatikireddiOffice of the Chief Scientist (CSO)SCAF/15/02IHW - MRC/CSO SPHU