The Drivers of Discretionary Utilization: Clinical History Versus Physician Supply

Because the effect of physician supply on utilization remains controversial, literature based on non-Medicare populations is sparse, and a physician supply expansion is under way, the potential for physician-induced demand across diverse populations is important to understand. A substantial proportion of gastrointestinal endoscopies may be inappropriate. The authors analyzed the impact of physician supply, practice patterns, and clinical history on esophagogastroduodenoscopy (EGD, defined as discretionary) among patients hospitalized with lower gastrointestinal bleeding (LGIB).

Among 34,344 patients hospitalized for LGIB from 2004 to 2009, 43.1% and 21.3% had a colonoscopy or EGD, respectively, during the index hospitalization or within 6 months after. Linking to the Dartmouth Atlas via patients' hospital referral region, gastroenterologist density and hospital care intensity (HCI) index were ascertained. Adjusting for age, gender, comorbidities, and race/education indicators, the association of gastroenterologist density, HCI index, and history of upper gastrointestinal disease with EGD was estimated using logistic regression.

EGD was not associated with gastroenterologist density or HCI index, but was associated with a history of upper gastrointestinal disease (OR 2.30; 95% CI 2.17-2.43), peptic ulcer disease (OR 4.82; 95% CI 4.26-5.45), and liver disease (OR 1.34; 95% CI 1.18-1.54).

Among patients hospitalized with LGIB, large variation in gastroenterologist density did not predict EGD, but relevant clinical history did, with association strengths commensurate with risk for upper gastrointestinal bleeding. In the scenario studied, no evidence was found that specialty physician supply increases will result in more discretionary care within commercially insured populations.