I want to go home: Can modelling the whole health care system reduce the number of patients waiting to leave hospital?

Dr Tom Monks puzzles the opportunities and pitfalls of modelling large parts of the health care system and how this might help patients waiting to leave hospital.

I work as a modeller for CLAHRC Wessex. In part that means I spend a lot of time speaking to health care professionals and commissioners about their priorities and teasing out if modelling could help.  More and more often I am asked “can we model the whole health care system?”.

One of the objectives underlying this question is the desire to reduce the number of patients in hospitals who no longer require to be there. The NHS call these delayed transfers of care. The big risk is that a patient’s condition will deteriorate while delayed and lead to a further round of treatment and/or adverse outcomes. This affects all patients, but is particularly pertinent for the elderly frail. A ‘whole systems’ view of health and social care is often necessary as it is the interaction between providers that holds the key to reducing these delays.

So how big is the problem?

We know that since mid-2014 the total number of days patients are delayed in hospital has increased by around 20%. This poses a significant problem for service users, their carers and those providing healthcare.

Can modelling the whole health care system reduce the number of patients waiting to leave hospital?
Total number of delayed days in acute and non-acute hospitals. There has been a 20% increase in delayed days since mid-2014

Let’s hear the good news first. There is indeed methodology available to assist with modelling a whole health and social care system or perhaps more accurately large parts of it. It is called System Dynamics. I have included a simple example model of this kind in the link below.

This is the model for you to experiment with

It is made up of two concepts:

Stocks (the blue boxes) that represent the location of ‘work’ or ‘patients’ and,

Flows (the blue arrows) that represent the rate at which ‘work’ moves from one stock to another.

In the model we focus on three elements of the health system: acute care, nursing homes and social care.

The model allows you change the number of nursing home beds available and the target social care workforce size.

Click on ‘simulate’ to run the model for one year and try different scenarios.

Just follow the link above and add your own numbers to see how the system perfoms
Just follow the link above and add your own numbers to see how the system performs

Note there are a few hidden difficulties built into the model

  1. The patient population ages and so more patients will need nursing homes and social care places over time
  2. The social care workforce is not available straightaway – it needs to be trained and retained.

Are there any limitations to such models?

Unfortunately yes there are. Undertaking such a project is a substantial research exercise and as such results will not be available over a weekend.  Moreover data are inevitably missing from complex model and will need to be collected or estimated in some way. This again adds time and complexity.

At CLAHRC Wessex we are working on System Dynamics models of the health system with our partners and in particular are focussing on the frail elderly.


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