A study has found that most doctors in Indiana aren't frequently using an electronic system designed to detect prescription drug abuse. The study presented to the state Board of Pharmacy by Indiana University's Center for Health Policy on Monday says nearly 90 percent of Indiana's doctors and dentists say they've prescribed controlled substances within the past year, but only about 20 percent say they've used the tracking system within the past month. Since 2004, the system has allowed doctors and pharmacists to determine whether patients are obtaining multiple prescriptions of powerful painkillers and other drugs that are often abused. Doctors say they would like the system to provide instant data instead of the current seven-day wait and they worry about police investigators invading the privacy of patients.