Predicting risk of hospital readmission with PARR-30

Approximately 8 per cent of patients discharged from hospital are readmitted within 30 days, costing the NHS an estimated £2.2billion a year.

Although NHS hospitals can use a model for predicting readmission (called PARR), it makes predictions over a 12 month period rather than 30 days. PARR was primarily designed for use by primary care trusts (PCTs) or community services to identify patients suitable for case management, rather than for hospital clinicians preparing patients for discharge.

Guidance on predictive risk modelling for commissioners

In August 2011 the Department of Health announced that it will not be commissioning a national upgrade of two predictive models: the Patients at Risk of Re-hospitalisation tool (PARR++) and the Combined Predictive Model. Scotland and Wales have their own predictive models called SPARRA and PRISM respectively.

Patients readmitted to hospital within a month of discharge cost the NHS £2.2billion a year, which is why this project is so important

To help commissioners, the Nuffield Trust is exploring a range of models that might be needed in future by the NHS in England. In November 2011 we published guidance that explores how clinical commissioners should choose a predictive risk model based on factors including the outcome to be predicted, the cost of the model and its associated software, the availability of data, the accuracy of the predictions, and the preventive intervention to be offered on the basis of predictions. This follows an article by Dr Geraint Lewis, Natasha Curry, and Dr Martin Bardsley for the Health Service Journal in October 2011.

The future of predictive risk modelling

In Canada, researchers have developed a simple tool, called the LACE index, which predicts readmission within 30 days. It was built using routine electronic information then converted into an index that hospital clinicians calculate manually when they are preparing patients for discharge.

It is currently being trialled by a group of Toronto hospitals to identify patients for admission to a Virtual Ward. For the first 30 days after discharge, patients who get a high score on the LACE index are managed at home by a Virtual Ward multidisciplinary team that offers them preventive care aimed at reducing their likelihood of readmission. The Virtual Ward staff, which includes a ward clerk and physician, hold daily ‘ward rounds’ and share a common set of notes.

A number of NHS hospitals in England are interested in the Toronto project, however its reliability cannot be guaranteed when used with different groups of patients to the one it was developed for.

We are carrying out a project to develop an equivalent to LACE for the NHS in England.  Known as PARR-30 this index will be developed using English NHS information.

The findings from this project will be published in a Nuffield Trust report in 2012.