Development and implementation of prospective outcome monitoring in a regional burns service using cumulative sum (CUSUM) techniques

Introduction

Real-time monitoring of mortality in burns units has the potential to immediately mark when mortality rates are significantly higher or lower than predicted. Rapid feedback from targeted internal audit allows early intervention, to reinforce positive practices, and improve systems where outcomes are unsatisfactory.This is the first study to describe prospective use of cumulative sum (CUSUM) methodology in mortality monitoring outside of cardiac surgery.

Methods

An eight-year retrospective study of mortality was performed on all admissions to a regional burns intensive care unit in the UK. Risk-adjusted CUSUM charts, variable life adjusted displays (VLADs) and zeroed VLADs were produced to track mortality against that predicted by the Belgium burns score. The same techniques were implemented prospectively for one year (76 admissions) using the Osler modification of the Baux score for risk adjustment.

Results

Internal audit would have been triggered on nine occasions using zeroed VLAD monitoring in the retrospective study. The Belgium score overpredicts mortality in the elderly.Internal audit was triggered for better than predicted outcomes on two occasions in the prospective study.

Discussion

This study describes a successful design for an early-warning system to monitor outcomes in a burns intensive care setting.