Numerous alert systems exist in healthcare domains but most of them produce too many false alerts leading to bad usage or disinterest. The need of better alert systems motivates the development of context-aware alert systems. The alert system Tempas is a help-decision tool based on personalized alerts. It is adaptable to business environment, target population, expert user needs, and customized in real-time for immediate needs by end users. The adaptability is defined during the alert creation process. The customization is defined during the alert management process. It is based on the population targeted, activation conditions, and the alert behavior. It is supported by two quality indices: the applicability index expresses how much a patient is concerned by the alert and the confidence index expresses how much the user can trust the alert. Both indices are used during the alert creation process (minimal thresholds for the population) and during the management process (minimal personalized threshold). The paper presents a summarized view of Tempas and focuses on the quality indices.