Some hospitals may regularly use tactics, some friendly and some threatening, to discourage patients from inquiring about their bills, according to a UC Davis researcher. Kimberly D. Elsbach, an assistant professor in the Graduate School of Management, is principal author of a study of hospital billing published in this month's edition of the journal Organization Science. "Citizens are becoming more educated about hospital billing and taking the responsibility of ensuring that their charges are correct," she said. "Hospitals are countering that with their own efforts to discourage people from becoming involved with challenges or audits because it costs them a great deal of time and money." The study shows that hospitals discourage inquiries by putting on a friendly face in their initial dealings, but those patients who call for an audit of their bills may meet with explicit hostility. Some hospitals try to prevent patients from launching a formal investigation by threatening to send a bill to a collection agency or to increase the charges. Elsbach found that the hospitals' tactics were successful: more often than not, the hospitals didn't need to act on their threats, and they saved the huge costs associated with consumer challenges. Begun in 1994, the study involved three unidentified hospitals and was based on bills, letters, observations and interviews with hospital staff and patients.