Why consultants need more natural predators

Without natural predators, growth in consultant numbers is uncontrolled.  This is the conclusion you reach when you look at the training numbers of doctors through an "ecological" prism: where doctors are the fertile mothers, and registrars in training are the juveniles who will grow to become future doctors.

Replacement fertility measures "the total fertility rate at which newborn girls would have an average of exactly one daughter over their lifetimes" who would go onto have further children. In more familiar terms, women have just enough babies to replace themselves.  It is a bit sexist to define this in terms of women alone, but as 50% female, Militant Manager does not mind.

In a stable ecology, replacement fertility is determined by a number of factors.  First is annual survival rates - the chance that you may die each year (predators, lack of food, disease etc).  Second is the age at maturation (the age at which a female can have children).  The lower the rates of survival each year, and the greater the age at maturation, the greater the replacement fertility.  And this equilibrium is stable because if numbers increased, then survival rates would drop as the population became easier to hunt, or they exhausted their food supplies.  A picture of a cow with an element of its replacement fertility is included for completeness below.

  

On this basis the replacement fertility for hospital consultants is 1 - i.e. consultants only need to have one registrar in their career.  And given 30 years of consultancy (which may increase if retirement is pushed back), and 6 years of training, the stable ratio of consultants to juveniles is 5 (this is 30 years of fertility in the consultant, divided by 6 years of maturation in the registrar).  The child bearing years are so long, the maturation age is so early, and the survivorship is so good, that in a stable population there would be 5 consultants per registrar.

And what ratio do we have today?  We have 5 times what we need, as illustrated in this spreadsheet, and summarised in the table below. 

Of course, the model needs to be adjusted for the more complicated reality.  People retire early, or change career.  There are some who go part-time (often the case for women); and others who go "private" entirely or in part.  There are even some who go to the dark side and become managers.

But these complexities only change things at the margin.  The replacement fertility ratio in humans is higher than the theoretical 2 (the theoretical figure).  This replacement fertility ratio ranges from 2.1 to 3.4 depending on country.  And similarly - though Militant Manager has not seen such an analysis - the stable ratio of consultants to registrars may be around 3 to 5:1.

Yet, we have a ratio of 1:1.  My spreadsheet is based on numbers published by the Information Centre.  This shows how the numbers have deteriorated over the last few years.  One can also see that vacancies for consultants are at negligible levels - the levels at which changes in recruitment practices in Trust will affect the numbers.

The more astute amongst the readers will be pointing out that I have not considered the growth that would be required.  That is by design.  The reality is that in a stable advanced economy, one cannot increase the workforce engaged in a sector without also saying in the same breath that that sector will also account for an increased share of GDP.  The UK already spends 8-9% of GDP on healthcare, and I do not see a groundswell to increase this further.  In fact, national policy is to reduce the share of GDP healthcare absorbs by keeping public spending on it constant as GDP grows.  So there are no grounds to independently plan for rapid growth in doctor numbers.

So what does this all mean.  I have four main thoughts:

1.  NHS Workforce leads should be sacked.  Not only have they allowed this to arise, they are asking the wrong questions.  Militant Manager has searched for years for strategic analysis of training numbers - what numbers do we need; and what drives the replacement ratio.

2.  There is going to be a lot of pain for trainees.  There was - not so long ago - a role for "senior registrars."  They were effectively registrars who had all the requirements for consultancy, but had to do "their time" waiting for a job to come up.  It was not unusual to be in such a stage for 5 years.  Those days are coming back.  And the 5 years will be used to erode, demoralise and reduce the registrar base.  Many will leave the profession, and lots of others will seek other ways to burnish their CVs to distinguish themselves in an the increasingly competitive process of becoming a consultant.

3.  We need a better plan.  Juniors now do a lot of activity in hospitals; and many rotas require them.  So in some respects there is a requirement for this number of registrar level doctors.  But we do not need those numbers "training" and aspiring to consultancy - an aspiration we cannot meet.  That will require a reduction in training throughput, and a change in the stable workforce mix in hospitals - away from "training" posts.  This is a task that will have to be picked up by the new HR directors who replace the sacked ones.

4.  We need more natural predators for consultants. Ideas include taking consultants and leaving them in the serengeti; encouraging more to go camping in Siberia; and introducing diving in the shark infested waters of South Africa as a training requirement.  

Readers will have better ideas, and I would welcome those.