In 2006, researchers handed 395 adults a pill bottle. The label said "Take two tablets by mouth twice daily." Then they asked each person to count out the pills they would take in a day. Among patients with low literacy, 71% could say the instruction back. Only 35% could count out the right number of pills (Davis et al., Annals of Internal Medicine). I keep coming back to that gap. People could read the words and still take the wrong dose. A page of labels like that one A hospital disc...