In the drive to link medical data from hospitals, clinics and doctor\u2019s offices, California is once again leading the charge. Exchanging medical data online can eliminate medication errors and streamline health-care costs. Until now, physicians, wary of for-profit entities and protective of patient confidentiality, have resisted the idea. Two Golden State nonprofit groups are in the throes of building online data exchanges?the first in the nation to let hospitals, clinics, doctors, pharmacies and labs in a given area share patient data. The nonprofit Santa Barbara Regional Health Authority funded the first and most comprehensive effort, the Santa Barbara County Data Exchange?an exchange that will link hundreds of health-care providers."If one of our students is injured on the weekend and shows up in a local emergency room and then on my doorstep a few days later, the exchange would allow me to access online any X-rays and lab tests that were taken over the weekend," explains Dr. Cindy Bowers, director of student health service for the University of California at Santa Barbara. "This way, I can treat the patient without waiting for a fax or having to make 29 annoying phone calls to get the information I need." Funded by a three-year, $10 million grant from the California Health Foundation, the Santa Barbara County Data Exchange has already grappled with the thorny issue of data access. The Philadelphia-based vendor working on the project, CareScience, has installed security and password protections. The project has moved into beta testing, during which nearly 50 physicians were able to access results from several local labs. Radiology results went online in March via a Web-based browser. Pharmaceutical and administrative data is scheduled to be online by the end of the summer. The intent is to link 1,500 providers in the Santa Barbara area with crucial medical information on approximately 300,000 patients. The second project, the Patient Safety Institute (PSI), funded by an $8 million grant from nine area technology companies, is more limited in scope and at a much earlier phase. It will help physicians retrieve patient data to improve decision making when prescribing medications. "Say, for instance, a physician wants to prescribe digoxin, the most commonly prescribed heart medication," says Dr. Jack Lewin, executive vice president and CEO of the California Medical Association and chair of the new nonprofit Institute. "In order to prescribe that drug, you need to know that the patient has normal kidney and liver functions and normal blood potassium levels, or there could be fatal side effects. This [computerized data exchange] will allow the prescribing doctor to find out what has been prescribed for the patient previously and what medical conditions they have." While an increasing number of hospitals are installing computerized exchanges in their own networks for inpatient use, the PSI and Santa Barbara projects cover the much larger and thornier domain of maintaining and securing data for outpatient care. If the Santa Barbara project can bring sensitive patient data online and keep it secure, it will boost the prospects for a nationwide medical data exchange.