On public health approaches to X
Why there probably isn’t a single ‘public health approach’
There has been a lot of talk of public health approaches to knife crime. London has set up a violence reduction unit and the commissioner of the Metropolitan Police has called for a public health approach. The Home Office may be about to adopt this approach.
But what do people mean when they talk about “a public health approach”? I think people mean different things, and I think this causes some confusion. Like when the Secretary of State for Health and Social Care said:
“If you try to say that it’s a public health issue that implies that it’s nobody’s fault.” (Matt Hancock, LBC, 4 March 2019)
Others have taken issue with this statement, but I think that the disagreement illustrates the confusion about how the term ‘public health’ is being used.
This blog is my crude attempt to describe some of the different things that people mean when they talk about the “public health approach”. I’ve blogged some thoughts about public health in the context of terrorism and the Government’s Prevent strategy. The ‘X’ in the title here is there because I’m not talking about knife crime or terrorism or anything else in particular. Instead I’m trying to sketch the various things that I think people mean when they use the phrase “a public health approach” to public policy more generally. But because lots of the discussion recently has been about violent crime, I’m going to use a lot of examples about violence reduction.
A public health approach is not…
First I think it’s worth saying what I think a public health approach is not.
It’s not free: sometimes you hear the ‘public health approach’ invoked as if it’s somehow an alternative to spending money on services. While I think the various ‘public health approaches’ are probably cheaper in the long run, I don’t think they’re magic. Prevention is about spending now to save more later. Short run costs may be higher as the investment in preventative action needs to happen alongside, and not instead of, investment in dealing with the consequences of the problem.
It’s not necessarily cost-saving: while prevention is usually cheaper than cure, that doesn’t mean it always releases cash to be spent elsewhere. The NHS spends money on services to get health and quality of life for the people that use them. It has to make judgments about which services are a good use of money, but it still recognises that buying health and quality of life is going to cost something. Public health folk like me need to be wary of letting people think that the same thing shouldn’t be true of preventative measures. Others have explained this better than I can.
It’s not just about data: while data is at the heart of public health, it’s not in my view what distinguishes it. Other professions and disciplines have an equal claim to being ‘data-driven’ (likewise ‘evidence-based’), and those of us in public health need to be careful not to give the impression that we think we’re the only people that ‘do’ data or evidence. If we think data is part of it, we need to say what’s particular about the way that we use data.
It’s not just about working across organisational boundaries: In its description of its ‘public health approach’ the London Violence Reduction Unit says that:
People often do not neatly sit within a service user grouping. Developing partnerships with and between organisations means that we can look across the system for solutions and not be too narrow in our approach.
This is no doubt right and true. And in public health we certainly recognise how policies outside of health cause populations to be sick or healthy. But it seems silly to imply that joining up organisations is somehow unique to public health. Frankly, we can be as bad at this as anyone else.
So what is ‘the public health approach’?
In short, I think that when you look at how people use the phrase, there is no one ‘public health approach’. Rather I think there is a range of features that are present to varying degrees in what people mean when they talk about the ‘public health approach’. None of them is wrong, nor are they mutually exclusive. But before we start taking a ‘public health’ approach to everything under the sun (obviously a great idea, but I would say that, wouldn’t I?) we probably need to try to spell out in each case what we mean.
The public health approach is … prevention
Yes, but prevention comes in different forms. Deterrence is an approach to prevention sometimes used in a criminal justice context. It probably doesn’t work (for example, sentence severity doesn’t appear to make any difference to crime rates), and I wouldn’t include it in a public health approach.
A public health approach to prevention would mean thinking about primary, secondary, and tertiary prevention. But beyond these relatively crude categories, it would probably involve a discussion about ‘going upstream’ — dealing with the real causes of whatever the problem is.
The public health approach is …infection control
The public health approach to violent crime grew out of the work of epidemiologist Gary Slutkin in the late 1990s who noticed that violent crime in Chicago looked like the infectious diseases he’d been studying in Somali refugee camps:
“The epidemic curves are the same, the clustering. In fact, one event leads to another, which is diagnostic of a contagious process. Flu causes more flu, colds cause more colds, and violence causes more violence.”
The work in Chicago inspired the Glasgow violence reduction unit that has been so influential in shaping the UK debate about a public health approach to knife crime. Both the Chicago and Glasgow models use ‘interruptors’ — credible messengers (often ex-offenders) to target people who have been victims of violent crime, in the knowledge that they are at risk of passing on the violence.
While control of infectious disease epidemics is core public health, it is one specific part of public health. And the infectious disease metaphor isn’t always mentioned in discussions of public health approaches. For example, the London Violence Reduction Unit doesn’t use the infectious disease metaphor when explaining what its public health approach looks like.
The public health approach is … epidemiology
This is what I think people sometimes mean when they talk about public health approaches being ‘data driven’. What this means to me is using the data to understand how the problem is distributed across different people, places, and times. It’s a particular approach to data.
There’s a set of tools — study designs, approaches to adjusting for confounding etc. that are commonly used. Some are shared with other disciplines. Other tools are being adopted from disciplines like economics.
The aim is to look beyond initial impressions and reveal underlying patterns. The Guardian has done some good epidemiology (though they’d probably call it ‘data journalism’) showing that, contrary to what the news reports suggest, knife crime has risen faster outside of London. Akala uses data well in this clip to make the point that knife crime is not new, the causes haven’t changed, and the idea that violence is linked to race is wrong:
The public health approach is … about populations
While public health involves doing things that manage risk for individuals — smoking cessation services and so on — we also recognise that focusing just on those people at the highest risk of some bad thing isn’t enough. This is not a new idea: in the 1980s Geoffrey Rose showed how, even though some people are at higher risk of strokes or heart attacks, most strokes and heart attacks happen among people at moderate risk, simply because there are so many more people at moderate risk than at high risk. Rose argued that we should focus on reducing everyone’s risk of disease at the same time as trying to help those at highest risk.
There is a tendency for this to get neglected even within public health. The health system loves ‘risk stratification’. This involves slicing a population up into sections at higher or lower risk of something bad, usually an emergency hospital admission. This popularity persists even though there’s little evidence that you can do anything about risk once you’ve identified it. Unsurprisingly population-level approaches don’t feature prominently in ‘public health approaches’ to wider public policy problems.
The public health approach is … about inequalities
Some groups of people suffer worse health, and to the extent that we can do something about this, it isn’t right. Any public health approach should look at the distribution of harm across different populations — whether defined by poverty, gender, race, sex, or gender. Encouragingly, the need to reduce such inequalities is written into the London Violence Reduction Unit’s approach.
The public health approach is … about structural causes
Maybe this is what Matt Hancock had in mind when he worried about nobody being at fault. Personal responsibility is a vexed political issue and free will is not a settled philosophical idea. I’m not going to try to tackle that here. Views across the public health community will differ, but it’s probably fair to say that public health approaches recognise that people make choices that are constrained by context. Again, this is not unique to public health — psychologists and sociologists have been saying this for ages.
Public health puts greater emphasis on the structural causes (like economic conditions, inequality, structural discrimination, policies and laws and so on) because these are where the evidence suggests that the biggest gains can be made, and where we have the best chance of narrowing inequalities.
The public health approach is … community development
‘Doing with not to’ is a popular phrase in public health. Asset-based community development (ABCD) is certainly a common feature of public health rhetoric, if not always practice. However this is something else that should probably be recognised as a thing in its own right, which public health does not have a monopoly on.
The public health approach is … about health
According to a well worn Cicero quote, “the health of the people is the highest law”. Quite a few councils have this as a motto. Sadly the issue of health gets lost in the debate. The question is: what are we trying to do? Is it decrease crime? Is reduce harm to victims? Is it to reduce the economic burden? For me, a public health approach would include an emphasis on the health harms viewed broadly (physical and mental health, the health of victims, families of victims, perpetrators, families of perpetrators, communities) as the overarching aim.
The list of things here almost certainly isn’t exhaustive. It’s also not particularly rigorous. Hopefully someone cleverer than me can turn into a proper taxonomy of public health approaches. For example, this interesting paper by Jorm et al suggests that:
The public health classification consists of six top-level classes: public health ‘Functions’; ‘Health Issues’; ‘Determinants of Health’; ‘Settings’; ‘Methods’ of intervention; and ‘Resources and Infrastructure’.
An accepted taxonomy of public health approaches might help policy makers who want to take a ‘public health approach’ quickly say what they mean (and just as helpfully, what they don’t mean).
