Consistency and variability in human performance during simulate infant CPR: a reliability study

Positive outcomes from infant cardiac arrest depend on the effective delivery of resuscitation techniques, including good quality infant cardiopulmonary resuscitation (iCPR) However, it has been established that iCPR skills decay within weeks or months after training. It is not known if the change in performance should be considered true change or inconsistent performance. The aim of this study was to investigate consistency and variability in human performance during iCPR.

An experimental, prospective, observational study conducted within a university setting with 27 healthcare students (mean (SD) age 32.6 (11.6) years, 74.1% female). On completion of paediatric basic life support (BLS) training, participants performed three trials of 2-min iCPR on a modified infant manikin on two occasions (immediately after training and after 1 week), where performance data were captured. Main outcome measures were within-day and between-day repeated measures reliability estimates, determined using Intraclass Correlation Coefficients (ICCs), Standard Error of Measurement (SEM) and Minimal Detectable Change (MDC_95%) for chest compression rate, chest compression depth, residual leaning and duty cycle along with the conversion of these into quality indices according to international guidelines.

A high degree of reliability was found for within-day and between-day for each variable with good to excellent ICCs and narrow confidence intervals. SEM values were low, demonstrating excellent consistency in repeated performance. Within-day MDC values were low for chest compression depth and chest compression rate (6 and 9%) and higher for duty cycle (15%) and residual leaning (22%). Between-day MDC values were low for chest compression depth and chest compression rate (3 and 7%) and higher for duty cycle (21%) and residual leaning (22%). Reliability reduced when metrics were transformed in quality indices.

iCPR skills are highly repeatable and consistent, demonstrating that changes in performance after training can be considered skill decay. However, when the metrics are transformed in quality indices, large changes are required to be confident of real change.