Measuring hospital-acquired pressure injuries: A surveillance programme for monitoring performance improvement and estimating annual prevalence.

Aims: To describe a surveillance approach for monitoring the effect of improvement initiatives on hospital-acquired pressure injuries and findings arising from that surveillance.

Methods: Random sampling of patients on the same day of each successive month from a campus of child and adult hospitals using a standard audit tool to identify presence of hospital-acquired pressure injury. Where multiple pressure injuries were present, the most severe grade injury contributed to prevalence. Statistical process control charts were used to monitor monthly performance and Maximum Likelihood Estimation to determine timing of step change.

Results: 8274 patients were assessed over 3 years from an eligible population of 32,259 hospitalised patients. 517 patients had hospital-acquired pressure injuries giving an overall prevalence of 6.2% (95% CI 5.7-6.8%). Annual prevalence was 8.4% (95% CI 7.4-9.5%) in the first year, falling to 5.6% (95% CI 4.7-6.4%) in the second year and 4.8% (95% CI 4.0-5.6%) in the third year. A step change was signalled with mean prevalence up to July 2013 being 7.9% (95% CI 7.1-8.8%) and mean prevalence thereafter 4.8% (95% CI 4.2-5.4%). Hospital-acquired pressure injuries were found in all age ranges, but were more frequent in children up to 14 years (17.4%) and those aged 75 years or older (38.7%).

Conclusion: Monthly random sampling of patients within clinical units can be used to monitor performance improvement. This approach represents a rational alternative to cross-sectional prevalence surveys especially if the focus is on performance improvement.