A study reported on October 3, 2016 in the Proceedings of the National Academy of Sciences claims that a doctor's political affiliation may affect the advice they give to their patient's concerning drug use, abortion, obesity, depression and gun safety. The researchers linked the records of 20,000 primary care doctors in 29 states to a voter registration database to determine their party affiliation. Of those 36% were Democrats, 31.5% were Republican and the balance were registered  independents or members of a third party. The researchers surveyed 1529 of the physicians evenly split between Democrats and Republicans. Approximately 20% of the doctors responded.

Republican doctors were more likely to: 1) discuss the health implications of marijuana use and encourage a reduction in use; 2) discuss the mental health aspects of abortion and to discourage further abortions. Democratic physicians were more more likely to urge patients not to keep guns at home. The authors concluded that just as a patient may prefer a physician of a certain gender, so too may a patient want to consider the physicians party affiliation.