Michael Barnett and colleagues published an article in the Archives of Internal Medicine that documents a rather large change in the annual rate of referrals to other physicians from physician office visits in the United States. "Trends in Physician Referrals in the United States, 1999-2009" concludes that the probability that an ambulatory visit to a physician resulted in a referral to another physician increased by 94% (from 4.8% to 9.3%) during this period.
The authors are not sure why this happened. One hypothesis they toss out for future study is that physicians are under pressure for time and therefore refer more. They note that "physicians are increasingly faced with more to do during the typical visit despite no meaningful change in appointment duration in 2 decades."
Whatever the reason, this change in behavior has a direct link to the rising cost of health care in the country. Specialists who see patients generally charge more than primary care physicians for a visit. Plus, a visit to a specialist is often likely to lead to a procedure or other intervention, again at an additional cost. Those specialist visits, in turn, are characterized by a huge variation in practice, providing a prima facie case that the care delivered in those offices is not driven by evidence.
The article provides a hint of some additional research that might shed light on the efficacy of different rate structures in influencing referral patterns. The authors say, "This trend was consistent across all subgroups examined, except for slower growth among physicians with ownership stakes in their practice . . . or those with the majority of income from managed care contracts."
I'm not sure what the ownership connection might be, but the managed care connection is clear. Even under a fee-for-service rate structure, insurance companies have enforced certain referral standards over the years, and doctors seeing those patients would probably be sensitized to the desires of those payers to avoid higher cost referrals.
Here's the hypothesis I'd like the authors to test: Would we see a difference in referral rates if we were to look at patients who are covered by capitated, or global, contracts compared to those covered by fee-for-service contracts? Given the dearth of information published so far about capitation -- and given the religious fervor evidenced by some proponents and their propensity to avoid transparency about results -- wouldn't it be good to see if it makes a difference? Some kind of objective test would be valuable.