Primary care providers and musculoskeletal referrals: Relationships make a difference

Background: A key assumption of the medical home model is that a stable patient-provider relationship will produce better management of a patient's acute and chronic health conditions. A plausible mechanism for this is an increased likelihood that appropriate referrals for preventive services will be made. Existing medical encounter data shed light on whether this referral pattern arises naturally or requires cultivation. Methods: The National Ambulatory Medical Care Survey (NAMCS) is a federally sponsored, annual, nationwide weighted sample of outpatient medical encounters. Data from 2008, the most recent available year, were used for this analysis. Analysis was limited to encounters involving physicians identified as being in primary care specialties. Visits were divided based on whether the physician (or practice) in the encounter was the patient's primary care provider, and whether the patient had been seen before by any provider in the practice. Because we wished to focus on musculoskeletal conditions and preventive practices, visits were also divided on the basis of the three-digit ICD-9-CM primary diagnosis code – 710-739 for musculoskeletal diagnoses versus all other diagnosis codes. Referral types selected for analysis were: exercise, injury prevention, stress management, physical therapy, and other orthopedic treatment. Analyses were conducted using the population weights included in the dataset and appropriate procedures in the SAS System. Results: Primary care providers were statistically significantly more likely (p=0.0001 to 0.001) to refer patients in primary care-flagged encounters to exercise programs than were non-primary care providers regardless of the acuity of the visit, the degree of establishment in the provider-patient relationship, or whether the primary diagnosis was orthopedic in nature. The only exception was in injury-related visits, where the difference in rates was similar but not statistically significant. Referrals to injury prevention services and stress management were significantly more common among primary care providers in visits not injury-related. There was no significant difference in referral rates to PT in most visit categories, and rates of referral to orthopedic services were lower for primary care providers than for other providers in all visit categories. These results did not differ significantly by patient gender or source of payment. Discussion: These results suggest that patients are more likely to receive referrals to basic musculoskeletal services (exercise, injury prevention) by their primary care physicians than by other physicians, even when those physicians are in primary care specialties. This pattern is less clear with more provider-driven referrals (PT and orthopedic specialty care).