Linda Aiken then addresses the role of nursing in providing quality health care, the impending gap between the need for nurses and the supply, the various ways that hospitals and other health organizations are reducing nurse staffing and increasing nurse workloads, and the many challenges these developments pose. Analysts have long known that the quality of nursing is central to preventing errors in hospitals and providing high-quality care. Aiken and her colleagues, as well as others, have demonstrated an association between nurses' workload and the number of deaths in hospitals. These researchers have also shown an association between nurses' education and the number of hospital deaths. Many hospital nurses are highly dissatisfied with their working conditions and lack of autonomy, and many leave nursing because of these dissatisfactions and burnout. Studies have suggested that when nurses have more control over their work, care improves and hospitals function better.