Money isn’t everything: the decline in medical imaging use

On the face of it, last October's report, 'Medical Imaging: Is the Growth Boom Over?' by the Harvey L Neiman Health Policy Institute, arguing that the length of the average hospital stay in the US has increased at the same time as use of medical imaging scans has declined, appears a cut-and-dried case of cause and effect.

However, as ever with these things, to leap to such a conclusion, and especially for policymakers, budget-holders or clinicians to leap to such a conclusion, would be dangerous: something that, to be fair, the institute itself has consistently stressed.

As institute chief executive Richard Duszak emphasises, the reality is that the factors behind the growth in imaging use that was seen in previous years, followed by its more recent decline, and the relationship (if one exists) of this growth to the wider trend of rising hospital stays, are both complex and nuanced.

"We are striving to make it very clear that we are not postulating causation, because that would be problematic," he says.

Nevertheless, the fact that there are these two clearcut trends - that the use of medical imaging scans is declining while, at the same time, the length of hospital stays is increasing - is something that needs to be recognised and considered very carefully, given the potential financial ramifications that both trends pose. Hospital admissions, after all, are among the largest, and fastest-growing, healthcare costs in the US.

More than just financial factors

As the institute's report concludes, "the recent marked slowing in growth of medical imaging appears to be sustained and multifactorial. Efforts directed toward further reductions in the utilisation of medical imaging should be tempered and based on a thoughtful consideration of the impact of policies, both enacted and envisioned, on overall population health, individual patient care, and downstream costs."

CT and MR imaging, we all know, has become an increasingly valuable tool in the physician's armoury in the years since it was first introduced, especially in regard to patient diagnosis.

"Imaging can help to shorten the timeline from presentation through to diagnosis," explains Duszak. "That then leads to an overall time-frame decrease, with shorter time to triage, to hospital admission and so on.

"If impediments are creating issues around availability when it comes to imaging, then the possibility exists that the time frame from presentation to diagnosis may not be as short as it could be. There has to be a value judgement around what is the balance between imaging and length of stay and hospital admissions, bearing in mind that a longer stay will mean greater cost and not be as good from the patient point of view, either."

What, then, in detail, is the institute saying? The research is the first policy brief produced by the institute, which conducts and supports research regarding medical imaging use, quality and safety metrics and human resources. It shows that there were a variety of factors behind the historic growth in imaging and, even more importantly, there is no one-size-fits-all reason (and certainly not just financial cuts) behind its more recent decline.

As Duszak himself explains in relation to the downwards drivers, "dollars are just one piece of it".

Growing awareness of risks and limitations

He adds: "For example, with the adoption of any new technology there is an initial exuberance, the sense that this is going to be the eureka development - and it clearly happened with CT and MR. So there may be an element of plateauing or slowing down going on as a result.

"There may also be a better understanding of what this technology can and cannot do and the wider promulgation of appropriateness criteria. There may, too, be a wider awareness among physicians of the possible downside risks of exuberant images, especially in regard to radiation exposure. But that does also, of course, simply increase the frequency with which those discussions happen.

"So you cannot look at this from the simple perspective of dollars spend with regard to imaging," he explains.

Nevertheless, just because it is too early to make a clear association or causation around the current decline and rise, the fact that it is possible to make such an association between the historic expansion and concomitant reduction in admissions, length of stay and so on is compelling.

"If you go back historically to look at where imaging was maybe six or seven years ago, what we saw was extremely fast growth and, in turn, associations with a number of things that could be considered as markers of improvement in patient care, such as numbers of admissions, length of stay and so on," says Duszak. "So should we not be thinking about the fact that, as imaging is now decreasing, there is at least the potential for some of these things to return to a natural baseline? What we are arguing is that, for policymakers, it would be wise to be careful when making these sorts of funding decisions.

"At the moment, it is not possible to make an association or causation effect. But to argue that what we are saying is, say, hogwash, you would have to go back and challenge a reasonably robust body of peer-reviewed literature going back over the past decade that is clearly making the opposite association when funding and imaging were increasing.

"I am sure there are some economic drivers behind the current reduction in imaging that we are seeing. There is certainly a lot of anecdotal evidence to suggest that cuts have in many instances become so substantive that imaging centres are even having to be closed. If there has been a genuine surplus, then, of course, such cuts might be a good thing. But downward pressure on payments has led to older scanners and a reduction in capital growth."

Imaging use in context

The key message, then, for lawmakers, regulators and medical professionals is that they need to recognise the importance of fully understanding or examining downstream effects before making medical imaging policy decisions. Imaging needs to be examined in the context of a patient's overall continuum of care and, just as importantly, in the wider context of ensuring that decisions taken around cost reduction do not, paradoxically, end up raising overall costs, creating barriers to care and, ultimately, harming patients.

"Cuts in unit spend may seem like an easy solution on paper, but there may be potential ramifications around patient care and access," says Duszak. "So you need, too, to be looking at what are the downside costs, are we being penny wise but pound foolish? We do not have all the answers, but what we do need to be having is thoughtful, careful conversations that consider not only the pure dollars equation but also the downside dollars risk as well as the wider clinical context."