Referrals of adult patients from primary care: demographic disparities and their relationship to HMO insurance.

BACKGROUND: Increasing enrollment in managed care organizations and dissatisfaction with policies to restrict direct access to specialists have intensified interest in referrals from primary care physicians to specialists. We examined the associations of demographic factors and insurance with referrals of adult patients by primary care physicians.
METHODS: Office visits of adult patients to primary care physicians (general practitioners, family physicians, and internists) reported in the National Ambulatory Care Survey for the years 1985 through 1992 were used to examine referrals by primary care physicians. Regression analyses were adjusted for patient factors (age, sex, race, insurance, case mix, diagnostic category, new problem or not, new patient or not, and visit length), physician factors (age, sex, specialty, and degree of specialization), and practice factors (proportion of HMO patients, rural location, region, and study year).
RESULTS: Overall, 4.5% of patients were referred compared with 7.5% of patients with HMO insurance. After adjustment, an increased likelihood of referral was associated with being a male patient, having fewer medications prescribed, not being seen before for the presenting problem, a longer visit, less physician specialization, seeing a female physician, seeing an internist, and seeing a physician with a greater proportion of patients with HMO insurance. Among patients with HMO insurance, no gender disparity in referral rate was observed, and patients who also had Medicaid or Medicare insurance were more likely to be referred.
CONCLUSIONS: Male patients are more likely to be referred. HMO insurance may reduce this gender disparity and increase the access of patients with Medicaid and Medicare to specialty care.