PORTLAND — Maine Medical Center launched a totally integrated electronic health records system this week that promises to benefit both patients and employees.

The roll-out of the “one patient, one record” system at Maine’s largest hospital is part of a seven-year, $150 million technology upgrade that is the largest-ever capital investment in health care in Maine.

By the end of 2013, the system will be adopted by seven other MaineHealth hospitals and their affiliated clinics, laboratories and physician practices in the state’s largest health care organization.

“It’s a big leap forward for us,” said Dr. Barry Blumenfeld, MaineHealth’s senior vice president and chief information officer. “It’s one of the best things we can do to improve the quality and safety of the care we provide.”

For the 1.5 million people in Maine Medical’s patient index, the secure, Internet-accessible system means all information about an individual’s doctor visits, hospital stays, prescriptions, laboratory work, x-rays, outpatient therapies, billing and scheduling will be kept in one place.

One of those patients is Phil Horwitch, who has been battling chronic lymphocytic leukemia for 12 years. In the past, Horwitch has carried x-ray results from one doctor’s office to another.

“I won’t have to do that anymore,” said Horwitch, 61, a Freeport man who was at Maine Medical on Friday. “The doctor will have it right there, so that’s a definite advantage.”

MaineHealth will receive a $50 million federal subsidy to adopt the new system, Blumenfeld said. The subsidy is funded under the Health Information Technology for Economic and Clinical Health Act of 2009, which was enacted as part of President Obama’s American Recovery and Reinvestment Act.

The federal government began promoting electronic health records in 2004 as a way to improve health care and paperwork, medical errors and costs.

The Obama administration added financial incentives to empower patients to participate in their health care, expand access to affordable health care and one day allow for a secure national network to share patient records.

Other Maine health care providers have made or are making the transition to electronic health records, including Central Maine Medical Center in Lewiston, Eastern Maine Medical Center in Bangor and Martin’s Point Health Care, which is based in Portland.

In the MaineHealth network, Miles Memorial Hospital in Damariscotta, Pen Bay Medical Center in Rockland, St. Andrews Hospital in Boothbay Harbor and Waldo County General Hospital in Belfast will adopt the new system in July, followed by Southern Maine Medical Center in Biddeford, Stephens Memorial Hospital in Norway and Goodall Hospital in Sanford in December 2013.

Electronic health records are getting mixed results.

In July, the National Center for Health Statistics released the results of a 2011 survey of nearly 3,200 doctors that found 55 percent were using an electronic health records system. In that group, 75 percent said their system played a “meaningful” role in their practice, 85 percent said they were either “somewhat” or “very” satisfied with it, and 75 percent said it improved patient care.

In August, Medscape, an online site for doctors, reported the results of a 2012 survey of more than 21,000 physicians in which 38 percent said they were “unhappy” with their electronic medical records system.

Blumenfeld said “very few” physicians in the MaineHealth system have objected to adopting the new system, in part because MaineHealth is covering 85 percent of their costs in the venture.

Blumenfeld said MaineHealth bought “the Cadillac” of electronic medical records systems, which has been adopted at several other leading national health care organizations, including the Cleveland Clinic, the Mayo Clinic and Geisinger Health System. The MaineHealth system combines Epic technology for clinical records and the Lawson system for financial records.

The MaineHealth system also includes the “MyChart” option, a secure, online portal that allows patients to get access to their health records, schedule appointments, view test results, manage medications and contact physicians via the Internet.

The growing use of electronic medical records has raised concern about maintaining patient confidentiality, however. Horwitch said he wasn’t worried about it after fighting a chronic illness for 12 years.

“They know more about me here than I do,” he said.

Maine Medical staff members said the new system went online this week with few glitches as nurses and other hospital employees accessed each patient’s records right in their rooms.

Many of Maine Medical’s 6,000 employees received several days of training to use the new system, including standard confidentiality requirements, said Deborah Linscott, a nursing director.

“There’s a learning curve,” Linscott said. “It will be a real time saver as they learn to make the program work for them.”

April Hothersall, an oncology charge nurse, said the new system reduces the chance of errors and redundancy in medical care. Notes on patient care are printed rather than handwritten, she said, and patient information flags potential drug allergies or interactions.

The new system also eliminates paperwork in the operating room, according to Dr. James Flowerdew, an anesthesiologist with Spectrum Medical Group in South Portland. In the past, a patient’s heart rate, blood pressure and other vital signs had to charted on paper every five minutes, Flowerdew said.

“Now the system is pulling all of the information from our anesthsia machines and vital sign monitors, and we’re electronically documenting all of the meds we’re giving,” Flowerdew said. “It’s going to make our work easier and improve care for patients.”

What if the electronic health records system goes down, as computer systems sometimes do?

“These really are just recording machines,” Flowerdew said. “They’re not providing patient care. If the system goes down, we know how to do the charts.”