NNAP audit measures

For full details of the NNAP audit measures please visit https://www.rcpch.ac.uk/work-we-do/quality-improvement-patient-safety/national-neonatal-audit-programme-nnap/measures

Understanding the caterpillar plots

In a caterpillar plot, networks are presented from left to right in the ascending order of their performance on the measure, with the most adherent shown on the right side of the graph. The performance in the measure (compliance) is shown by the vertical axis.

Each network is represented by a black dot, with a vertical bar above and below the dot representing uncertainty (statistically the 95% confidence interval) in this measurement of performance.

Although networks are ranked for presentation, the purpose of the plot is to demonstrate the variation, rather than to describe differences, between units with statistical confidence. Readers should therefore use these plots to assert differences between networks with caution because the observed differences may have arisen by chance.

“Treatment effect” is the difference between the rate of BPD or death in babies cared for in a neonatal network compared to the observed rate for a matched group of babies with very similar case mix, cared for in all neonatal units. A positive treatment effect indicates that the rate of BPD or death is higher in the network of interest than for a comparable group of babies cared for in all neonatal units. Where the 95% confidence interval for this effect excludes 0, the treatment effect is unlikely to be a chance finding.

Treatment effect is not displayed for Special Care Units because initial management of very preterm infants in Special care Units is, by definition, not planned and because Special care Units are unlikely to have sufficient numbers of very preterm infants attributed to them to make rates of BPD readily interpretable.