The odds that a patient visiting a physician would be referred to another physician – usually a specialist – rose by 94% between 1999 and 2009, while the absolute number of physician visits that resulted in a referral increased 159% during the same time frame, reflecting the rise in overall ambulatory visits during that decade.
The biggest increases were noted in referral rates from primary care physicians for patients with the following types of symptoms: cardiovascular (a referral rate of 8.5% in 1999-2002, increasing to 14.9% in 2006-2009), gastrointestinal (12.3% to 17.7%), orthopedic (12.4% to 16.5%), dermatologic (10.1% to 15.4%), and ear/nose/throat (4.5% to 8.5%), according to a study published Jan. 23 in the Archives of Internal Medicine.
Only physicians with ownership interests in their practices or those who obtained most of their income from managed care contracts had slower growth in referral rates.
The authors analyzed nearly 850,000 ambulatory patient visits in the National Ambulatory Medical Care Survey and the National Hospital Ambulatory Medical Care Survey, focusing on the decade 1999-2009.
It’s not entirely clear why referral rates are rising, according to Dr. Michael L. Barnett and his colleagues from Harvard Medical School, Boston.
"One possibility is that care is becoming increasingly complex, thereby requiring ever more care by specialized physicians," Dr. Barnett said. Evidence for this theory includes the fact that physicians increased referrals for patients with cardiovascular or dermatologic symptoms, but not for those who presented with more general symptoms, such as those associated with viral illnesses.
"Likewise, chief concerns outside the traditional spectrum of primary care, such as ocular or gynecologic/breast symptoms, had a consistently high likelihood of referral from [primary care physicians] but had no significant change in referral rate," they said (Arch. Intern. Med. 2012;172:163-170). "This suggests that some areas, such as cardiovascular and ear/nose/throat symptoms, may be increasingly outside the expertise or clinical portfolio of PCPs [primary care physicians] to manage alone. Other areas, such as gastrointestinal and orthopedic symptoms, had consistently increasing referral rates for PCPs and specialists, which may reflect increasing influence of those specialties in health care markets."
Another possibility is that PCPs simply have too much to accomplish during limited visits, with increasing screening and preventive recommendations, the authors noted.
While appointment duration has not changed significantly in more than 20 years, "patients require more medications and frequently have one or more chronic medical conditions," they said. "As a result... physicians, and in particular PCPs, may not have enough time to address each patient issue, resulting in increased rates of referrals."
Finally, growing numbers of specialists – plus better availability of specialist physicians in many parts of the country – may influence referral rates, the authors said.
It’s not clear whether the increase in referrals overall reflects any kind of an increase in inappropriate referrals, Dr. Barnett said, adding that little literature exists on how to define appropriate referrals. "The complexity of referral appropriateness is compounded by the multiple roles that specialists can play in the care of a patient, ranging from consultative to procedural to co-managing a complex condition."
The increase in referrals between 1999 and 2009 has implications for health care policy and health care spending in the United States, Dr. Barnett and his colleagues noted. "As federal and state policy makers consider policies for reforming the health care system, developing methods to measure referral appropriateness and using these to promote appropriate referrals may be an important strategy for controlling growth in health care spending."
The authors reported they had no conflicts of interest. Dr. Barnett reported no conflicts of interest.