Don’t blame the science

By Jonathan Michaels

When I wrote about the potential for injustices to arise in evidence-based healthcare policy, the COVID-19 pandemic had not begun.  Since then, numerous government agencies and academic bodies have rapidly produced policy, claiming legitimacy because it is “evidence-based” or “follows the science”.  However, science cannot determine policy, and the failure to distinguish the underlying evidence from assumptions and value judgements may lead to confusion and risks discrediting the science.

Science does not deal in certainties.  Many research results are presented as likelihoods and confidence intervals.  Even when experiments are devised to ‘prove’ a hypothesis, the proof is couched in terms of probabilities – such as the  ‘p values’ in medicine or the much more stringent sigma values in physics.

Research does not remove uncertainty but helps to characterise it.  With time, evidence will allow better predictions of the behaviour of the virus, although the economic effects and the human behavioural responses will remain less easy to forecast.  And there will always be the unpredictable; the “unknown unknowns” such as behavioural responses to a media storm over a policymaker who fails to follow their own advice or the failure of social distancing due to widespread demonstrations.

In the early days of a pandemic there will be few questions to which there is a proven scientific answer.  But lack of proof does not excuse policymakers from difficult choices.  Decisions must be made even where evidence is inconclusive.   A lack of conclusive proof for the benefits of the use of face masks in a pandemic is not sufficient justification for failing to recommend them if the balance of potential risks and benefits is in their favour.   The differing guidance that is apparently justified on the basis of the same evidence risks undermining public confidence in the science.

At best, decision makers might expect the science to provide justifiable estimates of the negative and positive consequences of their decisions on health, social behaviour and the economy.  Such predictions are necessary, but not sufficient to determine policy – there are competing drivers and trade-offs are required.  Science might predict the effects of particular measures to increase freedom of movement or gatherings on the spread of the virus.  Maximising restrictions will minimise the mortality and health effects of the virus.  Relaxation of restrictions may occur in many ways.  Prioritising social events, sport, religious gatherings or particular sectors of the economy are value judgements that reflect preferences related to individual freedoms, economic recovery, and physical or mental health.

Of course, economic and health consequences are inseparable.  At the start of the pandemic, delays in the implementation of measures was justified on the basis that the economic effects could kill more people than the virus.  However, even if a robust cost benefit analysis shows that more lives may be lost through an economic downturn than through the pandemic, accepting higher COVID-19 mortality as the lesser of two evils is not an inevitable policy response.  It is reasonable to question whether, in a wealthy democracy, a more ethical approach would be to minimise the mortality from the virus, whilst also focussing on measures to address poverty and mitigate the health effects of socio-economic deprivation.

Policymakers are used to such complex trade-offs.  Whether these are aspects of government policy underpinned by a cost benefit analysis or decisions on the rationing of new health technologies, there are policy frameworks that, at least in part, define the methods and value judgements required for such decisions.  However, in responding to the pandemic there appears to be little transparency about the underlying policy framework or the value judgements involved.  Without this, the labelling of decisions as ‘evidence-based’ risks adding to the distrust of science caused by misinformation and those who may undermine the credibility of the science.  Furthermore, it restricts the value judgements to those provided by the policymakers and scientists involved in decision making, excluding the public from contributing to an important debate.


Paper title: The potential for epistemic injustice in evidence-based healthcare policy and guidance

Author(s): Jonathan Michaels

Affiliations: School of Health and Related Research, University of Sheffield

Competing interests: None

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