A good service of social media makes going to the ER a bit easier. Besides looking for restaurant and hotel reviews, hospital and urgent clinics have postings on their Yelp pages. Users post much about their personal experience in a specific time, however now government information ( ProPublica, a non-profit public interest group based on patient surveys and data from the Centers for Medicare and Medicaid Services) can be found.
Yelp lists the data in the upper-right corner of my local hospital profile (image right) and has added a similar box to nursing home and dialysis center pages, find out how many beds and what the odds of surviving are. Not all US medical facilities at this blogging have such information. I am sure you will not use this Yelp information alone to decide upon where to pursue medical care. Many resources including this Medicare site that compares hospitals is well worth checking out.