Background: This study was designed to determine the variability in the consultation practices of family physicians and family nurse practitioners in an urban group practice, and to examine the relation between the referring practitioner's diagnostic certainty at the time of the consultation request, the specificity of the request to the consultant, and the frequency with which the practitioner ordered consultations in that specialty.
Methods: This study examined consultations requested by six family physicians and two family nurse practitioners that were directed to nine medical and surgical specialties in connection with 35,218 family practice visits made over a 19-month period in an urban family practice. Requests for consultation were scored based on the level of certainty of the referring practitioner's diagnosis at the time of consultation and the specificity of the consultation request.
Results: There was nearly a fivefold variation in the overall specialty consultation rates among providers, with even greater variation in each individual specialty area studied. Referral rate correlated positively with certainty of diagnosis (r = .40). There was no consistent relation between request specificity and referral rate.
Conclusions: Consultation rates vary widely, even among family physicians and nurse practitioners within the same practice. The rate at which a practitioner orders consultations in a specialty area increases in relation to the practitioner's certainty of the diagnosis at the time the consultation was requested. Diagnostic certainty is discussed as a possible indicator of a referring practitioner's knowledge in a specialty area, implying that the greater a practitioner's knowledge in a specialty area, the more he or she consults with specialists in the field. Financial incentives that attempt to decrease specialty consultation should be reexamined in light of these findings.