Health care is vital to Charlotte's economy when it comes to jobs and economic impact. The industry employs more than 116,500 people in the region — roughly 11 percent of the area's population. And the health and life-sciences sector had a total economic impact of $27.7 billion last year. "It's really a big engine for this community, relative to growth, job growth and economic growth," says Alan Sauber, chief ethics and compliance officer at Premier Inc. But the health-care industry is facing pressure as it braces for changes tied to how health care is delivered and paid for,Michael Tarwater, chief executive of Carolinas HealthCare System, told roughly 450 in attendance at the Charlotte Chamber's annual health-care summit.