My head swirls with a cloud of data. After a critical care unit was remodeled so that patient rooms were large enough to easily accommodate family, two-thirds fewer patients suffered falls. …Adapting rooms so that patients didn't have to move from ICU to intermediate care to hospital room as their condition changed cut medication errors by 67 percent. … HEPA filters cut rates of airborne infection. … More nurses disinfect their hands between patients if alcohol-rub dispensers are plentiful. … I look around this hospital and compare: There are alcohol-rub dispensers all around, but the rooms are small. I have no screwdriver to crack open the vent and check the air filter.

I wonder how my father would feel if he were in Boise, Idaho, at Saint Alphonsus Regional Medical Center, which is spending $161 million on remodeling and additions. Its plans were all set when a healthcare design member from the Center for Health Design came to visit and "practically got on his knees and begged us to change it," recalls Susan Gibson, vice president of mission services. "The new tower was between the two old ones, and a lot of the patient rooms had views of the other buildings. We redesigned the whole building for better views."

Besides those views of the Rocky Mountain foothills, the new project includes the fruits of Saint Alphonsus' own in-house research. The hospital built prototypes of its new rooms and asked nurses to critique them. The nurses asked for more work space in the medication rooms, where they assemble patients' prescriptions, and got it. "They needed to be able to concentrate," Gibson explains. "It was a way to try to reduce their stress and reduce medication errors."

Saint Alphonsus also had a "design lab" incorporating proposed features. To create it, the hospital turned a floor of offices in its existing building into 40 private rooms for patients, each setup with zones for patient, family, and staff. The new unit has high-­quality acoustic ceiling tiles, carpeted halls, art opposite each patient's bed, and alcoves where nurses can update charts and remain close to their patients. Once patients moved in, the staff recorded data about noise and sleep. They found that while some hospitals see noise levels surge to 90 decibels, this unit kept noise to an average of 51 decibels, and, perhaps not surprisingly, its patients rated the quality of their sleep much higher than patients on other floors (on a scale of one to 10, the new unit rated 7.3 compared with just 4.9 elsewhere). "By building this unit, we learned a lot. We'll change some things for the new one. We also learned which things we definitely wouldn't give up, our nonnegotiables," Gibson says. "First on that list are the acoustic tiles."

Gibson's enthusiasm is infectious. And that's precisely the idea behind the Center for Health Design's Pebble Project, in which hospitals that are renovating or building get access to volumes of research and recommendations about design in return for gathering their own data about the design's effectiveness once construction is complete. Dozens of hospitals are participating, with more joining all the time.

That's heartening to Cama and the others compiling the evidence for evidence-based design, particularly because healthcare construction is booming, and it's only going to continue to grow. Last year alone, hospitals spent more than $16 billion on new buildings and on renovating old ones, and that number is expected to reach $20 billion annually by decade's end, fueled in part by the expectation of baby boomer demand for healthcare and by the fact that new technology doesn't fit easily into vintage hospital buildings. "People thought outpatient services would take over hospitals, but instead, it just took all the patients who could be handled that way," Cama says. "We're still filling hospital beds, and because those patients are sicker, hospitals need to be more like ICUs than places to recoup for a few days. They need to be much more technologically advanced, so we have to build new buildings or renovate not-so-old buildings."