Quality improvement in health care. Conceptual and historical foundations.

During the past decade, quality improvement (QI) has become the primary approach for health care organizations to measure performance and implement change. From a historical perspective, QI has multiple origins: in systems engineering, as a way of defining production processes; in quantitative analysis, as a methodological approach for collecting and analyzing data; and in organizational behavior, as a way of understanding how QI fits with an organization's structure and management philosophy. Although QI and evaluation share similar goals, as modes of inquiry, they developed in very distinct and separate settings, to fulfill different needs. However, these differences are now beginning to merge as QI gains acceptance as a desirable and legitimate approach for health care organizations to enhance service delivery and outcomes. This article describes the conceptual foundations on which QI is based and identifies historical events that have influenced the development of QI and its adaptation by health care organizations.