When doctors in the research were given a patient's medical history and symptoms, which they then matched to information entered into a symptom checker, clinicians made the accurate diagnosis 72 percent of the time, compared to 34 percent for the apps. They also took patients' temperatures about as often as the app did (about 95 percent of times), measured blood pressure about as often (77 vs. 57 percent), and conducted physical examinations only about half the time (45 vs. 91 percent). Here's how often doctors performed basic health checks on patients: weight almost all the time, 98 percent; height almost always, 97 percent; blood glucose test before eating any food containing carbohydrates more than twice a week, 88 percent; eye exam almost always, 87 percent. The app missed these tests entirely or rarely performed them. The study's authors concluded that "mobile health tools may have a role in facilitating access to care for individuals with low-frequency health concerns," but they also noted several limitations to their work. For example, they relied on data from people who chose to use the apps and not everyone who has a mobile device uses a health app. And while most of the health checks included in the study were done regularly, some were not. For example, only 45 percent of patients received a weight check up until two years prior to being enrolled in the study.