This statistic is one of my favorites. The Wall Street Journal sourced it from a 2011 study conducted by the Commonwealth Fund. Most likely, the Commonwealth Fund concluded this information based on the percentage of doctor bills on people’s credit reports. They then looked at the likeliness of medical billing errors happening and multiplied that by the first number.As a result, they could conclude that the amount of Americans with errors affecting their credit is a little higher than the entire population of Pennsylvania.