More prescription drug plans try coinsurance.

As more Americans turn to medications to manage everything from heart disease to hair loss, employers are gazing anew at drug benefit designs in search of better ways to control costs.

Their concern is understandable: Forty-four percent of the population takes at least one prescription drug - up from 39% in 1994 - according to a new report from the Centers for Disease Control and Prevention. Prescription drugs accounted for 10% of the $1.6 trillion Americans spent on health care in 2002 and were the fastest-growing expenditure.

Many firms introduced three-ti