What you should know

Who's going on strike? 4,800 nurses represented by the Minnesota Nurses Association at five Allina Health facilities: Abbott Northwestern Hospital and Phillips Eye Institute in Minneapolis; United Hospital in St. Paul; Mercy Hospital in Coon Rapids, and Unity Hospital in Fridley. Nurses plan to set up picket lines on Sunday morning, then picket from 7 a.m. to 7 p.m. for seven days.

Will the hospitals continue to admit patients? Allina has arranged to hire 1,400 replacement nurses from all across the country. They will work mostly 12-hour shifts, and Allina says patient care should be as normal.

Are nurses allowed to strike? Yes, federal labor law allows nurses to strike, as long as they give the hospitals 10 days' notice. The theory is that nurses would otherwise be powerless to protect their interests in an economic and collective-bargaining system in which hospitals, doctors and insurance companies all have incentives to protect their interests at the expense of others.

Why a seven-day strike? The union felt that a shorter strike, like their one-day walkout in 2010, wouldn't exert enough pressure on Allina, but a longer work stoppage would jeopardize patient care.

Can Allina fire the striking nurses? No, federal labor law protects their jobs under these circumstances. But Allina reserved the right to call nurses back gradually if the strike causes a reduction in patient numbers.

What's the core dispute? Allina insisted that the nurses give up their union-backed health insurance, which was designed in an earlier era of collective bargaining. Allina says it would save $10 million annually by moving nurses to company health plans that offer financial incentives for the use of efficient forms of care, such as generic drugs instead of brand names. Nurses want to preserve their plans with higher premiums but lower deductibles, because they were earned in negotiations at the sacrifice of other benefits, and because their jobs leave them prone to workplace illnesses and injuries that require treatment.