American doctors tend to be the highest paid in the world, with salaries that can double that of their counterparts outside the United States. That makes it all the more surprising that doctors here tend to have way lower rates of job satisfaction, according to new research from the Commonwealth Fund.

The nonprofit surveyed primary care doctors in 10 industrialized countries. American doctors turned out to have the lowest rates of job satisfaction. When asked whether our health-care system worked well, about 15 percent agreed.

It's worth thinking a bit about the factors driving the low rates of satisfaction. It doesn't seem to be salary: While primary care doctors earn less than specialists, their salaries still outpace those of their international counterparts.

A lot of the frustration seems to stem from a lack of health-care access: In 2012, 59 percent of American doctors reported that their patients had difficulty paying for care. "Satisfaction with primary health care practice appears to be related to physicians’ perceptions of patients’ access to care," the authors of this report write. "Within eight of the study countries (all but Australia and France), doctors concerned about patient access were significantly less likely to be satisfied with practicing medicine (data not shown)."

The lack of access in the United States has a lot to do with our high uninsured rate. It also has to do with prices: the unit costs for health care are hugely higher in the United States than they are in other countries. A hip replacement in the United States can cost three times as much as it does in France.

One other element tends to be a lack of coordination. The United States came in at the bottom of the pack when the Commonwealth Fund surveyed doctors on whether they got looped in on their patients' care. Sixteen percent were informed when a patient's drug regiment changed. Twenty-three percent said they would know if their patient had made a trip to the emergency room. You can see the full results here:

The lack of coordination in the United States, coupled with the barriers to access, seem to be two of the key factors that have the vast majority of primary care doctors thinking that the health-care system we have right now just isn't working.