As health care across Canada struggles with staffing shortages, a Globe investigation has found that provincial use of private nursing agencies has recently skyrocketed – in some cases costing hundreds of millions of dollars.The Globe’s Kelly Grant and Tu Thanh Ha have been investigating these private agencies – and one agency in particular – for months. Today, they tell us how these agencies work, why it’s costing so much, and the concerns with how some of these companies are operating – including some questionable expenses that are being passed onto taxpayers.Questions? Comments? Ideas? Email us at thedecibel@globeandmail.com