Do mattresses make a difference?
D000328:Adult; D000368:Aged; D001512:Bedding and Linens; D006801:Humans; D008875:Middle Aged; D011140:Polyurethanes; D011312:Pressure; D003668:Pressure Ulcer / Q000517:prevention & control*
D011140:Polyurethanes; C028279:polyurethane foam