By SINDYA N. BHANOO

COPENHAGEN - Jens Danstrup, a 77-year-old retired architect, used to bike all around town. But years of smoking have weakened his lungs, and these days he finds it difficult to walk down his front steps and hail a taxi for a doctor’s appointment.

Now, however, he can go to the doctor without leaving home, using some simple medical devices and a notebook computer with a Web camera. He takes his own weekly medical readings, which are sent to his doctor via a Bluetooth connection and automatically logged into an electronic record.

“You see how easy it is for me?” Mr. Danstrup said, sitting at his desk while video chatting with his nurse at Frederiksberg University Hospital, a kilometer and a half away. “Instead of wasting the day at the hospital?”

He clipped an electronic pulse reader to his finger. It logged his reading and sent it to his doctor. Mr. Danstrup can also look up his personal health record online. His prescriptions are paperless - his doctor enters them electronically, and any pharmacy in the country can pull them up.

All of this is possible because Mr. Danstrup lives in Denmark, a country that began embracing electronic health records and other health care information technology a decade ago. Today, virtually all primary care physicians and nearly half of the hospitals use electronic records, and officials are trying to encourage more “telemedicine” projects like the one started at Frederiksberg by Dr. Klaus Phanareth, a physician there.

Several studies conclude that the Danish information system is the most efficient in the world, saving doctors an average of 50 minutes a day in administrative work. And a 2008 report from the Healthcare Information and Management Systems Society estimated that electronic record keeping saved Denmark’s health system as much as $120 million a year.

Denmark’s success has much to do with the its small size, its homogeneous population and its regulated health care system. As in much of Europe, health care in Denmark is financed by taxes, and most services are free.

“It was a natural progression for us,” said Otto Larsen, director of the agency that regulates the system. “We believe in taking care of our people, and we had believed this was the right way to go.” He and others acknowledged that the system is hardly perfect. It faces budget constraints, and the country is still refining common standards for electronic health records. “We’re trying to streamline now,” Mr. Larsen said. “There are too many systems out there.”

At Thy-Mors Hospital in the rural region of North Jutland, doctors are using I.B.M. software that pulls data from a patient’s electronic health record and superimposes it on a three-dimensional image of a human body, allowing doctors to quickly get an overview of the person’s medical history. The doctor can rotate the image, zoom in and click on ailments.

The ambulances have access to electronic medical records, so medical technicians can update them for the doctors even as patients are on their way to the emergency room.

Back at the 150-year-old Frederiksberg University Hospital in Copenhagen, a nurse, Steffen Hogg Christensen, was preparing medical information kits like the one Mr. Danstrup uses.

Health information technology is no easy task, Mr. Christensen said. Training colleagues and elderly patients can be daunting and time-consuming.

“But isn’t it amazing, how innovative we can be?” he said, smiling broadly. “And all in these old walls.”