US Trends in Physician Referrals

Referring patients to specialists remains a major factor in determining the quality and cost of healthcare. Patients who are referred to a specialist tend to incur greater healthcare spending compared with those who remain in primary care. Appropriate specialist referrals improve quality of healthcare; however, overuse of referrals may increase use of healthcare services with no benefit in outcomes. In addition, referrals require coordination of care directed by the primary care physician (PCP). Noting that there are few data on national trends of physician referrals over time, researchers recently conducted an analysis of ambulatory physician referrals from 1993 to 2009, with a focus on the 10-year period from 1999 to 2009. They reported study results in Archives of Internal Medicine [2012;172(2):163-170].

Utilizing data from the National Ambulatory Medical Care Survey and the National Hospital Ambulatory Medical Care Survey, the researchers also examined referral rates for specific subgroups of patients and physicians, including an analysis of referrals from PCPs and specialists according to the category of patients’ primary reason for the visit. The analysis was stratified by patient characteristics, physician characteristics, and setting of the visit. Variables included patient age (0-3, >3-18, >18-45, >45-65, and >65 years), sex, race (white, black, and other), insurance (private, Medicare, Medicare, and other/uninsured), and geographic region (Northeast, Midwest, South, and West). Physician characteristics included whether physicians practiced in a solo setting, owned their own practice in part or in full, made consults with patients by e-mail or telephone (data initially collected in 2001), had any form of electronic medical record, and received >50% of their income from managed care contracts or Medicaid (initially collected in 2003). Specialties were grouped into 2 categories: primary care, including physicians in general and family practice, internal medicine, and pediatrics without subspecialty, and specialist, which included all other physicians.

The researchers assessed how frequently PCPs or specialists referred patients with particular symptoms in 1999 to 2002 and in 2006 to 2009, using the first listed, or most important, reason for the visit given by patients. The analysis revealed that in the 10-year period from 1999 to 2009, the probability that a visit to a physician resulted in a referral to another physician (referral rate) increased from 4.8% to 9.3% (P<.01), a 94% increase. During the same time period, the number of ambulatory visits in the United States increased from 841 million to 1130 million per year (from 3040 to 3720 visits per 1000 persons annually). Combining the increase in number of visits with the increase in referral rate, the researchers said there was a 159% increase in the national absolute number of visits resulting in physician referral (41 million in 1999 to 105 million in 2009). The referral rate for Medicare beneficiaries during the same time period increased from 4.2% to 9.7% (P=.003).

Combined with the increase in number of visits annually, the increase in referral rate translated to an increase of >350% in the number of visits resulting in a referral for this population. For PCPs, there were variations in referral rates according to the principal symptom associated with the patient’s visit. There were significant increases between the 1999-2002 and 2006-2009 intervals for visits with primary symptoms in the cardiovascular (8.5% to 14.9%; P=.001), dermatologic (10.1% to 15.4%; P=.03), ear/nose/throat (4.5% to 8.5%; P<.001), gastrointestinal (12.3% to 17.7%; P=.007), and orthopedic (12.4% to 16.5%; P=.003) categories. Changes in PCP visits for symptoms such as general/viral, gynecologic/breast, and ocular were not statistically significant during the study period.