Extent of diagnostic agreement among medical referrals

Diagnostic uncertainty is often encountered in a medical practice. Patients with ambiguous, uncertain, and undiagnosed problems are frequently referred for second opinions. Comparing referral diagnoses to final diagnoses provides an opportunity to determine how frequently final diagnoses vary and changes the direction of medical care.

A retrospective study was done at a single academic medical center using a sample of 286 patients referred by physician assistants, nurse practitioners, and physicians from primary care practices from January 1, 2009 to December 31, 2010. Patients' referral and final diagnoses were compared and classified into 1 of 3 categories: referral diagnosis and final diagnosis the same, referral diagnosis better defined/refined, and referral diagnosis distinctly different from final diagnosis. Episode costs for the respective categories were calculated for the referral visit and services that occurred at our facility within the first 30 days.

In 12% (36/286) of cases, referral diagnoses were the same as final diagnoses. Final diagnoses were better defined/refined in 66% (188/286) of cases; but in 21% of cases (62/286), final diagnoses were distinctly different than referral diagnoses. Total costs for cases in category 3 (different final diagnoses) were significantly higher than costs for cases in category 1 (P = .0001) and category 2 (P = <.0001).

Referrals to advanced specialty care for undifferentiated problems are an essential component of patient care. Without adequate resources to handle undifferentiated diagnoses, a potential unintended consequence is misdiagnoses resulting in treatment delays and complications leading to more costly treatments.