Summary Objectives The purpose of this study was to test the reliability of the Resuscitation Predictor Scoring (RPS) Scale1 (Appendix A), a survival prediction nomogram designed to aid resuscitation termination decisions during a resuscitation attempt. Method Bivariate comparisons of predictors of survival and survival rates between the primary RPS Scale data set (1993–2000) and a secondary data set (2000–2003). A total of 2121 patients were included in the study. Results Comparisons of the two sets of data showed an increase in resuscitation attempts for patients ≥80 years ( p < 0.001); an increase in pulseless electrical activity (PEA) ( p = 0.01) and an increase in the duration of arrests ( p = 0.012). However, in relation to the RPS Scale there were no statistical differences in survival between any of the sub groups demonstrating the reliability of the nomogram. Conclusion The final updated RPS Scale demonstrates predicted survival rates 15 min into a resuscitation attempt. These can be poor and suggest that it is an acceptable point at which to first consider termination (where there has been no ROSC). The RPS Scale has demonstrated reliability and validity, but can only be a guide for the cessation of resuscitation.