Doctors would be able to increase the number of physician assistants they supervise from four to eight under a measure passed Tuesday by the House. The bill was approved by a vote of 100 to 19 despite concerns by some lawmakers that the change would mean spreading the attention of supervising physicians too thin, resulting in less oversight by the professional who is ultimately in charge. "I wanted to support this until I read it and there is no definition of what supervision is," said Rep. Carl Zimmerman, R-Dunedin. He said he supports broadening the duties of licensed assistants, "but I just can't expand that to people who are not going to be supervised."