Capacity, utilisation and peak demand

In our last big discussion at LP on problems in the public health system (regarding the Coalition plan to initiate a revamped hospital training program for new nurses) a lot of us pointed fingers at the bean counters as the reason why hospital nurses no longer have time to provide patients with the emotional support that used to be a core feature of nursing, a support which patients – sorry, should I use the bean-counters’ preferred term, clients? – regularly complain about no longer receiving.

In all the discussion of last week’s hospital scandal about the woman who miscarried in the Royal North Shore Hospital (RNSH) Casualty toilet area while waiting for obstetrical assessment and a bed, people (including the NSW Health Minister Reba Meagher with her knee-jerk directive which has no funding or staffing attached to implement it, and Federal Health Minister Tony Abbott’s Fantastic Voyage advocating the olden days of competing and duplicative local boards) seem mostly upset about the reported lack of sensitivity and emotional support shown by the staff in the system. With all the sympathy in the world for the woman’s ordeal and the couple’s emotional trauma, I think this focus misses some key points about the fundamental reason that ER departments regularly have unacceptably extended wait times, which is not just about understaffing and overwork in the ER itself.

Some of you probably know much of these basics already, but bear with me while I get to the crux, which is a common shortfall in all public hospitals around the country, not just RNSH.

ER management always involves triage, but when peak demand periods mean that beds are filled to capacity, Casualty has to rigidly triage which patients most urgently require actual intervention. Miscarriage is usually not such a case, as there is very rarely anything that can be done to stop miscarriages proceeding, and most miscarriages, while painful, are not seriously endangering the health of the mother, requiring sympathy support rather than medical measures. Those miscarriages that are endangering the mother (haemorrhaging, drastically reduced/elevated blood pressure etc) are rushed through to treatment because of those other signs of miscarriage complications. There simply is not the staff to spare for emotional support for a patient who is not going to die without treatment, callous though such decisions may seem and undignified though the resulting pain and misery may be.

Much of the public reaction to the ordeal of miscarrying women in the ER seems, firstly, deep sympathy for them undergoing such emotional trauma while in such an impersonal environment with no privacy or dignity; secondly, anxiety about truly serious cases being overlooked by an overstressed emergency system; and thirdly (and rarely voiced), pure apprehension regarding a stereotype of squeaky clean suburbanites being surrounded by bashed and bleeding drunks and junkies as they all wait to be attended to.

In an ideal hospital, pregnant women presenting with signs of possible miscarriage would have a special area to go to, attached to the obstetrics unit, with sympathetic permanent staff providing privacy and as much reassurance as possible (as “Grim Reba“‘s directive attempted to magically apparate). There would be similiar areas for other patients with severe but non-life-threatening conditions to wait in more privacy than the triage area as well. If our hospitals had a better balance between capacity, utilisation and peak demand, such areas would perhaps be possible, but as the situation currently stands the decisions made on recommendations from bean counters in parliaments, bureaucracies and hospital administrations have made it totally impracticable. Not just impracticable for such luxuries as retiring rooms for pregnant women or chronically ill patients, but also increasingly impracticable in terms of delivering quality emergency care at all, with increasing warnings that our emergency departments are routinely so stretched that they are on the verge of endangering lives simply through being overwhelmed.

There’s very little excuse for it either: Operations Research utilising Queueing Theory is a long-standing discipline, has repeatedly been applied to hospital wait times, and the current situation in our hospitals is totally predictable in light of past administrative decisions. Decision makers in hospital administrations and health bureaucracies have either deliberately chosen to develop a system that is regularly delivering these extended wait times, or have incompetently ignored expert advice that would have told them that such extended wait times would regularly occur.

As my pet statistician summarised it on my request especially for this post:

An A&E department is a complex system, but lends itself well to analysis by the branch of mathematical modelling known as queue theory. In simple terms, this states that the system becomes overloaded when the utilisation of a service momentarily exceeds its capacity. Notice the word ‘momentarily’. This is a key point to understanding the issue. The average utilisation of a system tells us little about the variability in utilisation over time. When arrivals are regular, the system can operate at close to capacity without being overloaded. In contrast, when arrivals are more random, the system needs higher capacity to be able to service peaks in demand.

If patients are not to be left waiting for substantial periods the A&E department must have adequate capacity to deal with peak demands that are significantly greater than the average. Using computer network capacity as a reasonably analogous model, a rule of thumb is that delays in the network become noticeable when the average throughput is more than 70% of the total capacity. A computer network run at 90% capacity would certainly exhibit extended delays and would be in serious danger of catastrophic failure. If this model is an accurate predictor, we would expect that a hospital A&E department where the presentation rate was 90% of capacity would place lives at risk by being unable to cope with peaks in demand.

The analogy is not exact because hospital A&E have a triage process that allows them to prioritise their work so that more urgent needs are dealt with first, but there must still be adequate capacity in the triage process to handle peaks in demand. Even if the triage process itself is not overloaded, urgent cases ‘jumping the queue’ have a progressively deleterious effect on treatment times for the less urgent cases.

So, while running a department at less than 70% of its capacity may seem wasteful, it is in fact necessary and is commonplace in other systems that attempt to cope with random arrivals.

It’s not just the wait times in the ER itself. It is the system’s capacity to move patients requiring hospital admission out of the ER and into a bed: there are two interlocked queueing systems, and administrative decisions in the name of “efficiency” have vastly increased the wait times in both queues.

“Faced with diminishing government subsidies, competition, and the increasing influence of managed care, hospitals are under enormous pressure to cut costs. In response to these pressures, many hospitals have made drastic changes including downsizing beds, cutting staff, and merging with other hospitals. These critical capacity decisions generally have been made without the help of OR model-based analyses, routinely used in other service industries, to determine their impact. Not surprisingly, this has often resulted in diminished patient access without any significant reductions in costs.” [link]

Public hospitals in Australia are currently utilised at 90-95% capacity i.e. 90-95% of beds are filled every single day, according to the AMA. This leaves very little spillover margin for periods of peak demand, and materially increases the wait time required to move new inpatients from ER to a ward. If those patients have to wait in the ER treatment area (where else can they wait?) , they take up space which could be being used to assess and treat patients from the ER triage area, so those patients then have an increased wait time as well.

By contrast, according to AMA representatives discussing the issue in the media last week, three-star and above hotels aim for an average 80% utilisation of their accommodation capacity in order to run the hotel most efficiently, allowing for sudden influxes in the case of unpredictable events (airport closings etc) that lead to peak demand. Hotels aren’t the only industry that regularly underutilises their full capacity in order to adequate cope with periods of peak demand. Utility companies live and die by avoiding service outages during peak demand periods:

  • Telecoms have a rule of thumb that if their network isn’t large enough to keep average utilisation down to 60-65% of capacity, then the network will fail at periods of peak demand.
  • Electricity and water suppliers, although I don’t have the specific capacity/utilisation/peak demand figures to hand, also allow a large margin between full capacity and average utilisation in order that the system won’t fail in periods of peak demand.

Our public hospitals have been pushed to be more “efficient” by demonstrating high average bed occupancy rates, as well as demanding that nurses and other hospital staff spend more time on easily quantified paperwork than on patient care that can’t be measured in terms of injections and pills. It’s important to note that the paperwork demands also mean that the time of nursing staff is utilised at average 95% of time capacity, again leaving little leeway for peak demand periods, as nursing staff are still obligated to do that paperwork no matter what. These unreasonable demands are part of what feeds a culture of bullying staff that exacerbates care delivery shortfalls even further.

Until our public health bean-counters and policy-makers, at all levels, understand that it is prudent rather than wasteful for beds and staff not to be utilised at 95% capacity every single day, there will continue to be people subject to unnecessary ordeals in peak demand periods that could be so much less traumatic, and so much less life-endangering, if proper Operations Research and Queue Theory were better applied in organising bed occupancy targets and staff shift duties as well as rostering arrangements. The current arsecovering by the NSW Premier, regarding any inquiry into last week’s miscarriage events being confined just to the facts of that individual case rather than an investigation of the hospital as a whole, merely attempts to obscure the real problem which will continue to fester. The attempts by the Howard government to point the finger at the Iemma administration as if they are the sole cause of the problem, rather than noting the contribution of a longstanding federal ideological commitment to “economic rationalist” methods of organising health (and other) systems, doesn’t help deal with the real problem either.

Obviously, maximising hospital wait time efficiency according to the recommendations of Queue Theory would involve extra cost. It has repeatedly been shown that a majority of taxpayers would be willing to pay a higher Medicare levy in order to fund a better public healthcare system, yet the Federal Government has only ever produced ideological rationales for not raising funds allocated to public health while enjoying repeated budget surpluses. No amount of finger pointing at the various State Governments’ dysfunctions in public health can negate the Federal Government’s contribution to the current problems.

Categories: culture wars, health, medicine, Politics


5 replies

  1. All valid points, of course, but I think the woman who miscarried in the toilet highlights another fundamental problem with the system, which is that women don’t have publically-funded access to one-to-one midwifery care.
    If this woman had had a primary care midwife, she would not have been at the mercy of the hospital e.r.

  2. Rebekka beat me to it. With funded, resourced, supported community midwifery, women could miscarry in the privacy of their own homes, with family and midwife support, only transporting if an emergency requiring intervention arose. And if they did need transport, their midwife would be there with them for support and to help them navigate the system.
    This isn’t an excuse to not resource hospitals properly of course, but it’s a medically safe, emotionally supportive, cost-efficient system that is being pointedly ignored (when it’s not being actively campaigned against) by current government.

  3. I don’t have figures for the electricity industry either, but that’s an interesting comparison.
    Because the demand for electricity from the grid comes from millions of consumers, it is possible to predict that demand with great precision. The electricity supply industry has necessarily become very good at estimating the amount of electricity required at any given time and the infrastructure is organised to have the required generating capacity on line when it’s needed. Changes in demand are addressed by bringing additional generating stations on-line just in time to handle peaks and taking them off-line when demand slackens. By contrast, the demand for electricity from a smaller number of consumers, say 100, would fluctuate wildly and the generating capacity required would be disproportionately larger. This latter case is more analogous to the A&E situation.
    To carry the analogy a little further, when the total generating capacity is allowed to remain static or even reduce while the daily peak demand is trending upwards, as happened in California a few years ago, the consequence is rolling blackouts.

  4. My wife is an experienced emergency medicine doctor, currently in the middle of training to become a fully qualified emergency physician, and we’ve talked about this a lot. If pointed her to this post, I think she’ll be fascinated.
    One aspect which gets completely missed in the current political debate (well, Julia Gillard has mentioned it, but no one else seems to have picked up on it) is that a major contributing factor is the failure of aged care, largely due to poor handling by the federal aged care ministries in the 90s (Bronwyn Bishop, mostly). Many aged care facilities were closed and have not been replaced, and instead that means elderly patients who would be in aged care hostels, remain in hospitals. Those beds remain full long term, and full beds means emergency departments are not able to push patients out the back of the department into the hospital. And, as they can’t refuse to accept patients in genuine need, that means they bank up in the emergency department, which is not designed for it. This problem, access block, is the biggest problem for emergency departments.

  5. Dave: Yes, someone pointed out exactly that over at LP, where I crossposted this.
    In NSW approximately 10% of acute care beds are occupied by people who should be in continuing care beds in hostels and nursing homes. But those beds simply don’t exist, and for all the fingerpointing of the Federal govt at the State govts for dysfunctional health care management, the responsibility for an adequate supply of continuing care beds is totally a Federal area. Canberra has not only cut the level of funding they give to public hospitals, they are literally stealing resources by foisting their continuing care patients onto the acute care system.
    mr tog: good points about the difference with the electrical supply predictability

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