Population puzzle. Suburban sprawling.

What's a hospital to do when hundreds and even thousands of new residents move into its formerly quiet little community every month? That's the predicament that Dixie Regional Medical Center in Utah and many other boom-town hospitals are in; they must decide how to transform themselves to meet the needs of a rapidly changing marketplace. City hospitals face a similar challenge: affluent young professionals and empty-nesters revitalize certain neighborhoods while other areas lose their long-time- and well-insured-population base to the suburbs.