Family practice referral patterns in a health maintenance organization.

In one year, 3.85 percent of the 12,228 patient visits to a family practice clinic resulted in referral. The members of the health maintenance organization (HMO) had a referral rate of 4.46 percent, while fee-for-service patients had a referral rate of 3.19 percent. The fee-for-service patient population was similar to the HMO group, except for the significantly different rate of referral. Comparison of the referral patterns suggests that this difference is influenced by economic factors.