The sleek hospital tower that Johns Hopkins Medicine built in 2012 has the frills of a luxury hotel, including a meditation garden, 500 works of art, free wi-fi and a library of books, games and audio. As Dr. Zishan Siddiqui watched patients and some fellow physicians in Baltimore move from their decades-old building into the Sheikh Zayed Tower, the internist saw a rare opportunity to test a widespread assumption in the hospital industry: that patients rate their care more highly when it is given in a nicer place. For decades, hospital executives across the country have justified expensive renovation and expansion projects by saying they will lead to better patient reviews and recommendations.