Policy Makers Should Use Evidence, But What Should They Do In an Evidence Vacuum?

There are two points of view concerning the obligations of policy makers when there is no direct evidence to guide them:

  1. It is wrong to take any action or intervene unless there is evidence to support your decision.
  2. A lack of evidence is neutral; it neither allows a decision-maker to intervene, nor does it sanction non-intervention.

Which is correct? Writing in the Lancet recently, Feng, et al. advocate the use of face masks in public to prevent the spread of COVID-19.[1] They say it is an asymmetrical choice; unlikely to do harm and may do much good by preventing the spread of the disease from pre-symptomatic people to people who are unaffected.

The ARC WM Director sides with the ‘lack of evidence is neutral’ principle. In my opinion the argument that a policy maker should not intervene in the absence of direct evidence is flawed for a series of linked reasons:

  1. The obligation to use evidence when it exists does not entail the requirement to fail to act when there is no such evidence.
  2. Further, there is never a circumstance in which no relevant evidence is available. Granted, there may be no direct, comparative evidence, but this is not tantamount to no evidence at all.
  3. There can be no automatic supposition that the expected value of a proposed intervention is less than that of the status quo. That is to say, the balance of benefits, harms and costs may go either way when there is no incontrovertible comparative evidence. It is then a matter of judgment as to the relative probabilities of benefit and cost that must sit alongside values in determining the best course of action.
  4. The theoretical basis for decisions under uncertainty derive from expected utility theory, which reconciles probability and values/preferences.[2][3] Under this axiomatic theory, probability refers to the decision maker’s degree of belief. 

Of course, nothing written above should be misinterpreted to imply either that good evidence should not inform decisions or that policy makers have no obligation to try to collect evidence to better inform future decisions. Indeed, the mandate to collect and use evidence is now enshrined in law in many states in the USA and was a manifesto commitment for the current UK government.

The US state of Oregon is well known for ground-breaking policies. Right back in 2003 it passed legislation requiring evidence-based procurement of clinical services in the field of addictions beginning 2005.[4] By 2011, 75% of addiction services commissioned by public money had to be evidence-based.[5] Likewise, nearby Washington state published a law in 2012 requiring policy makers to use empirically supported services for children’s health and welfare.[6] 

The British government has a tripartite structure for policy trials:

  1. Funding universities to carry out policy trials to inform the government’s programme. A good example is The Work and Health Unit (WHU) trial of an intervention to encourage small- and medium-sized enterprises (SMEs) to do more to promote employee health and welfare.[7] The WHU have sponsored ARC WM faculty, supported by the West Midland Combined Authority and RAND Europe, to carry out a four arm cluster randomised trial of 100 SMEs.[8]
  2. Funding external ‘what works’ centres, such as the Education Endowment Fund that was established in 2011 by The Sutton Trust with £125m funding from the Department for Education. This organisation has conducted a very large series of educational RCTs, in which England now leads of the world, as recently described in your news blog.[9]
  3. In-house trials conducted by individual government departments. I am a member of the Cabinet Office ‘What works trial advice panel’ that advises on in-house and externally commissioned trials whatworks.blog.gov.uk/trial-advice-panel/. HMRC has conducted the largest-ever RCT of self-assessment tax schemes, for example. The environment agency has recently conducted an RCT to tackle waste crime. I am currently part of a small group advising government departments on the design and evaluation of an intervention to help people who have recently become carers to adapt to their new circumstances without becoming depressed, and in some cases being able to continue to work.
  4. Funding academic centres, such as DHSC policy research centres.

ARC West Midlands will continue to promote local and international studies to provide evidence for evidence-based policy. We like to work very closely with policy makers and service managers so that our work addresses their immediate needs. We like to think of ourselves as pioneers in the fields of rapid response and opportunistic research, and can cite a number of on-going and recent examples, many covering the areas of public health and social care.

Richard Lilford, ARC WM Director; with thanks to Emily Power for contributions.


References:

  1. Feng S, et al. Rational use of face masks in the COVID-19 pandemic. Lancet Resp Med. 2020.
  2. Thornton JG, Lilford RJ, Johnson N. Decision analysis in medicine. BMJ. 1992; 304: 1099-103. 
  3. Lilford RJ, Braunholtz D. The statistical basis of public policy: a paradigm shift is overdue. BMJ. 1996; 313: 603.
  4. Oregon Legislative Assembly. Human Service Issues: Health Care. Senate Bill 267. In: 2003 Summary of Legislation. Oregon: Legislative Fiscal Office; 2003. p59.
  5. Rieckmann T, et al. Employing Policy and Purchasing Levers to Increase the Use of Evidence-Based Practices in Community-Based Substance Abuse Treatment Settings: Reports from Single State Authorities. Eval Program Plann. 2011; 34(4): 366-74.
  6. Trupin E, Kerns S. Introduction to the Special Issue: Legislation Related to Children’s Evidence-Based Practice. Admin Policy Ment Health. 2017; 44(1): 1-5.
  7. Thrive at Work Wellbeing Programme Collaboration. Evaluation of a policy intervention to promote the health and wellbeing of workers in small and medium sized enterprises – a cluster randomised controlled trial. BMC Public Health. 2019; 19: 493.
  8. Lilford R, Russell S, Sutherland A. Thrive at Work Wellbeing Premium – Evaluation of a Cluster Randomised Controlled Trial. AEA RCT Registry. October 17 2018.
  9. Lilford RJ. UK Takes Over From the US as the Home of Trials of Educational Interventions. NIHR CLAHRC West Midlands News Blog. June 1 2018.

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