Evaluations of the quality of medical care often focus on processes of care, such as how often patients receive certain tests or treatments. Some people believe that a better way to measure quality of care would be to look at patient outcomes, such as how often they become sick enough to need hospitalization or how long they live. Unfortunately, it is often more difficult to measure patient outcomes than to measure processes of care. First, measuring patient outcomes requires following the patient for a long period of time. Second, patient outcomes depend on other factors, such as patient age or their baseline level of health, in addition to the quality of the medical care they receive. Theoretically, there should be a link between recommended processes of care and outcomes (such as patient survival), but few studies have examined this link.