Using Simulation and Forecasting in Ophthalmology Services for Planning and Development

Demand on NHS managers to deliver on time and in budget has never been more intense.  Eye care services account for nearly one in ten hospital outpatient appointments in England.  Increasing demand for ophthalmology services with limited healthcare budgets has put hospitals under immense pressure. 

Increasingly hospitals are considering how sophisticated statistical techniques might help to address these problems.  The latest advances in forecasting techniques in healthcare can provide highly accurate forecasts of future demand for hospital services.  These forecasts provide a reliable basis for planning future services. 

NICE encourages the use of simulation in its recent paper by the Decision Support Unit, Cost Effectiveness Modelling Using Patient Level Modelling, April 2014. 

Operational level simulations of hospital services can help managers understand the impact demand for services will have on resources.  They enable the impact of service changes to be tested in the safety of a validated virtual environment.  Managers can see the effect their decisions have on activity, cost, staffing levels, clinic/staff utilisation and waiting times. 

The combination of highly accurate demand forecasts with an operational simulation provides managers with reliable quantitative information, which was previously unavailable, about how a service will perform in the future.  

Pathway Communications has developed the simulation and forecasting tool, OCCUSIM, for ophthalmology service managers by combining forecasting with simulation to provide reliable information about the future performance of a service. 

1. Forecasting

Understanding where an ophthalmology service will be in six months’ time, let alone a year’s time, is too often a luxury for managers.  It is common that in house teams lack time to provide complex forecasts for individual services.  This genuine problem leaves managers reacting to issues, rather than proactively planning how to deal with them, before they have a detrimental effect on the service. 

Using the Hospital Episodes Statistics (HES) dataset or the hospitals own data, the simulation and forecasting tool forecasts demand for an ophthalmology service to provide an accurate view of 12 months into the future.  State-of-the-art forecasting methodologies, and sophisticated statistical software which treats each age group separately, rather than as a homogenous group, produces forecast results that are 85-95% accurate. 

Automatic updates of the forecasts each month, enable managers to carefully monitor the metrics that are most important for their service and compare these to targets.  This provides an early warning of up-coming problems so managers have more time to implement plans to mitigate any negative impacts on the service. 

1. Simulation

An accurate forecast of demand is vital for planning an ophthalmology service, however managers also need to understand how this demand will impact on the resources required to deliver the service (staff utilisation and service hours, numbers of diagnostic and treatment procedures to be carried out, utilisation of clinics, theatres and beds, revenue and costings, and future requirements for agency staff).  By combining accurate forecasts of demand with an operational simulation that mimics the reality of an ophthalmology service, managers can see the relationship between future predicted demand and the impact on resources.  

An operational level simulation enables the day to day running of the service to be explored in detail.  It captures the complexities of the ophthalmology patient pathway, representing the patient’s journey through the service, incorporating all the resources used, and significantly, the constraints imposed on these resources (for example service hours, availability of the resources etc.).  These many resources and their constraints make it virtually impossible to manually consider all the interactions that take place at one time, as well as their effects on each other. 

The programming expertise required to develop such specialist simulations is only available from a small number of qualified individuals in the UK.  Pathway Communications has experience of developing such simulations and of working with clinicians to create simulations that enable organisations to easily test the effect of change. 

Combining the use of sophisticated statistical forecasting techniques to produce highly accurate forecasts, with an operational service simulation, is believed to be unique.  Pathway Communications is not aware of this approach being used elsewhere.  The Macular Society is working with Pathway Communications to develop this significant new tool for ophthalmology services. 

1. Ophthalmology simulation and forecasting 

The simulation is developed to enable resource use to easily be established.  It predicts the numbers of: 

• First and follow up appointments
• Did not attends
• Cancellations
• Diagnostic and treatment procedures
• Average waiting times
• Utilisation of clinics, theatres and beds
• Staff utilisation and service hours
• Revenue and costings
• Requirements for agency staff 

Also developed to quickly test the impact of making changes to the service, changes can be made to many variables, including: 

• Appointment booking systems
• Consultation time
• Diagnosis procedures
• Treatment regime
• Drug options
• Number of follow-ups
• Staff types and numbers 

This enables managers to explore the impact of making changes within the safety of a validated virtual environment, so that many different “what if…” options can be tested, and the most effective option identified. 

Results of different options are displayed in the form of graphs and charts that compare the current position with changes, so they are easy to interpret and can be used to create an evidence based view of the future of the service. 

The simulation and forecasting tool is developed to enable managers to answer such varied questions as: 

• What would the impact be of the new budget set by government?
• What would happen if NICE guidance is fully implemented?
• What would be the impact on our service if the demand for diabetic macular oedema (DMO) treatment increases?
• How would a Saturday clinic impact our service?
• What if we add a nurse injector into our service? 

1. Case Study 

An illustration of how Trust X has used data from the simulation and forecasting tool is described below.  

The tool predicts the expected number of first attendances, follow-up appointments, cancellations, DNAs and new to follow-up appointments ratio.  Trust X’s ratio of first to follow up appointments is shown below. 

 The results show that the trend in the ratio of first to follow up appointments will increase from 3 to almost 5 over the next 12 months.  

Trust X’s predicted admissions versus discharges are as follows: 

 Trust X is able to identify that the increasing ratio of first to follow up appointments may be due to the low discharge rate.  With this early warning, Trust X has time to consider alternative options to reduce future pressure on their ophthalmology outpatient department. 

Trust X is considering 2 options; patient reviews with active discharges where appropriate, and outsourcing some of the follow up appointments.  The impact of both options are tested using the simulation and forecasting tool.  

1. Conclusion

The NHS is facing an extremely challenging environment.  By combining the latest techniques in forecasting with simulation the tool provides managers with reliable information about the future performance of their service.  Developed to enable the impact of change to be easily tested within the safety of a virtual environment, managers can quickly explore many different options and identify the most efficient solutions. 

For more information about the simulation and forecasting tool, OCCUSIM contact us at [email protected]