Dignity Health, which runs a large network of hospitals out of its San Francisco headquarters, also offers online ER booking at Saint Francis Memorial Hospital in San Francisco and Sequoia Hospital in Redwood City as a way to overcome the frequently grueling emergency room wait times.

Dignity isn’t the only network employing the strategy. In an era of increased competition driven by the nation’s Affordable Care Act, hospital executives around the country are hoping online appointments will attract patients eager to avoid long waits in a crowded and often chaotic environment.

Emergency room appointments are not intended for patients with serious emergencies — those with life-threatening, debilitating or urgent medical conditions.

The approach makes business sense for hospitals because it lets medical staff know who may be coming through the emergency room door and helps reduce crowding and decrease wait times, hospital executives say. They say the service also helps build a loyal clientele among patients.