Most physicians favor state legislation that prohibits secondary sources, such as pharmacies, from selling prescribing information to data-mining companies for commercial purposes. However, 85% of doctors have no problem divulging their prescribing practices to the pharmaceutical industry through market research questionnaires. Those are some conclusions from a new Internet survey of physicians conducted by market research firm TNS Healthcare. TNS also found that to date, only a fraction of physicians (4%) have made use of AMA's opt-out program that keeps their prescribing information from being shared with pharmaceutical sales reps. The TNS study was conducted in January and covered 1,000 doctors.