Wednesday, 14 December 2016

The way the NHS measures average bed occupancy doesn't support effective solutions to the shortage of beds

News headlines today (the BBC's on increasing occupancy of beds and The Times on nighttime discharges) reflect a real problem with bed occupancy in NHS hospitals. But the metric on average bed occupancy doesn't measure what it claims to measure and actively distracts from practical solutions that would improve the system.

The NHS has been collecting data about bed occupancy and availability for a very long time. But just because the statistic has been around for a long time doesn't mean it is useful. Sure, it measures something, but whether that something helps the NHS do a better job is highly questionable.

I first came across the metric in the early 2000s when I was working on problems in A&E departments and realised that finding a free bed was one of the biggest barriers to quick treatment. It still is. What I discovered was that the way the metric is measured is about as useless as it is possible for a metric to be. It not only doesn't help solve real problems, it actively drives people to suggest the wrong solutions.

The trouble is that what we need to understand is why beds are hard to find at the particular time of day and day of the week when they are needed. Peak arrivals at A&E, for example, usually occur between 9am and 10am. So the demand for beds for the 1 in 4 patients in A&E who need to be admitted peaks sometime before lunchtime. That's when we need the beds at least for the uncontrolled flow of emergencies. (In principle, hospitals can control the timing of the flow into elective beds though many don't.)

But the bed occupancy metric doesn't tell us about the availability of beds at the point when they are needed. Nor does it tell us about the average occupancy across the day or the week. It tells us about the number occupied on a particular day of the week at midnight. When I first started working for the NHS I expressed astonishment that the statistic was so irrelevant to the real problem of finding beds when you needed them. I was told that such a long standing practice could not be changed.

The reason why the metric is so useless in practice isn't hard to understand. In a typical DGH with 500 beds, each day will see somewhere between 75 and 100 discharges. In many hospitals those discharges typically happen in the afternoon, often late in the afternoon. This doesn't match the demand for beds which is dominated by emergency admissions which peak in the morning. It isn't helpful to know how many beds are free at midnight: we need to know how many are free every hour of every day.

If we focus purely on the published metric the only way to fix a lack of availability is to add more beds and hope discharges don't become any less disciplined (unfortunately there is plenty of evidence that things will get more relaxed and the beds will fill up with patients who should have been discharged more quickly). If we focus on the pattern of arrival and departure across each day we can see better ways to create space for emergencies. I supported the Department of Health to develop a Bed Management Toolkit in 2007 that recommended a focus on doing as many discharges in the morning as possible (this is still part of good practice recommendations now). If a good proportion of the 75-100 patients are discharged in the morning, there will be plenty of free beds for the emergency admissions. If they stay in their beds all day awaiting slow processes to get them out (like prescriptions for take home medication or discharge notes) then the hospital may well find itself running out of free beds early in the afternoon even though it will have free beds later in the day. Patients in A&E will spend a long in an environment that isn't the best place for their care. There is plenty of evidence that small changes in discharge practices can make big differences to bed availability at the times of day when beds are needed.

In the hospitals who do collect real time bed utilisation, this pattern can be seen and managed. Surprisingly, many can't even collect this data and many who can do nothing to ensure that the data is collected reliably. Others do collect it and do nothing with it.

My main point is that the national bed occupancy metric tells us nothing useful about the problems many have finding beds at the time of day when they are needed. Worse, it tends to lead commentators to demand a major increase in bed numbers, which is both unrealistic and could only happen slowly, rather than a focus on the effective management of discharges, which could yield benefits tomorrow at minimal cost. There are hospitals who genuinely need more beds in the medium term, but a failure to manage discharges effectively makes their problem much worse right now.

The NHS could argue that the problem is outside its control because many patients can't be discharged because of a lack of social care capacity. It is true that this is a big and growing problem. But it isn't the biggest problem. Audits of clinical notes of patients currently in beds usually show that between a quarter and a half are fit to leave hospital. And while perhaps a third of those are stuck because of external problems the rest are stuck because the hospital hasn't got its discharge act together. But, what the hell, it is far easier to be able to simply blame others than it is to do the hard work required to redesign processes inside the hospital.

But back to my main point. Average occupancy isn't very much help and the nationally reported metric doesn't even measure average occupancy. Hospitals need to understand real-time occupancy every hour of every day if they are to have any hope of managing the availability of beds at the times of day when beds are needed. Good systems to manage bed occupancy can lead to major improvements in bed occupancy at the points of the day when it matters and, as a direct result, will dramatically reduce long waits in A&E. This involves understanding of the pattern of demand across the day and a disciplined approach to discharges that achieves much better coordination of departures with the pattern of demand.

If the NHS continues to focus on a bad way to measure the wrong thing about beds it won't get the insight it needs to drive real improvement.