Final answer:
The NCQA monitors health care quality changes over time, with data sets often examining changes over multi-year spans, as reflected by graphs depicting percent change at an annual rate during different economic periods.
Step-by-step explanation:
The National Committee for Quality Assurance (NCQA) focuses on the improvement of health care quality. When discussing sustained and statistically significant changes in the context of NCQA, it usually refers to changes observed over a specific period. These changes are often tracked over multiple years to establish a trend or to assess the impact of policies or health interventions. For example, a graph demonstrating the Percent Change at Annual Rate indicates how certain events, such as economic recessions, can affect health care metrics. For instance, in years like 1970, 1974, 1981, 1983, 2008, and 2020, the rate was notably low, coinciding with periods of economic downturn in the U.S.