IMPORTANCE Despite the importance of identifying and reducing wasteful health care use, few direct measures of overuse have been developed. Direct measures are appealing because they identify specific services to limit and can characterize low-value care even among the most efficient providers. OBJECTIVES To develop claims-based measures of low-value services, examine service use (and associa...

H AVE YOU EVER HAD a magnetic reso-n a n c e i m a g i n g (MRI) scan of your brain? I have. I was lying on a plank in my underwear and a hospital gown, with a cold peripheral intravenous (IV) line in my arm and a woolen blanket draped over me. A plastic cage was closed on my face to steady my head, and headphones with thick cushions covered my ears, playing the Dave Matthews Band inaudibly. I ...