Objectives. Accidents in health care, resulting in injury or death to the patient, are a matter of considerable concern. The aim of this study is to examine whether system weaknesses can contribute to these accidents, and if so, how. Design. Eight consecutive accidents reported to the Health Authority in Sweden were analysed using MTO (Man-Technique-Organization) analysis. Setting. Emergency care hospitals in Sweden. Results. All cases that involved the system supported the assumption that

more »

... m weaknesses are a contributing factor to accidents. In this study two types of latent failure could be identified: process control latent failures and interactional latent failures. The time span from activation of process control latent failures to operator error was very short, and the study demonstrates the simple relationship between situational factors and operator errors. Interactional latent failures exert system influence in a more indistinct manner. Latent failures, as seen in this study, act not only by creating opportunities for operator errors but also by hindering error detection in the time window available. Safety barriers, which might have prevented the accidents, could be proposed in seven out of eight cases. Conclusion. System weaknesses seem to play an important role in accident evolution. Consequently, certain measures can be suggested in order to improve patient safety: (i) sufficient resources should be allocated for research and development at both medical schools and hospitals in order to establish competence and procedures for systematic analyses of processes; and (ii) authorities handling accident cases should have adequate competence in system analysis.