Economic impact of an ultrasonographic contrast agent on the diagnosis and initial management of patients with suspected renal artery stenosis

Abstract

Objectives: To determine resource use in the diagnosis and management of Canadian hypertensive patients with suspected renal artery stenosis and to estimate the impact of diagnosis with contrast-enhanced duplex Doppler ultrasonography (US) on resource use.

Subjects and methods: Seventy-eight patients with suspected renal artery stenosis underwent usual diagnostic tests (captopril-enhanced renal scintigraphy or duplex Doppler US) and contrast-enhanced US. A management pathway ("planned") describing the medical resources required for further patient care was outlined on the basis of results from each test (separately), and a modified management pathway ("recommended"), which considered data from both diagnostic methods, was also outlined. Medical resources and productivity losses were assessed prospectively for a 3-month period after patients underwent both tests ("actual" management pathway).

Results: With usual diagnostic methods, 14 (18%) of the tests were inconclusive, whereas only 1 (1%) of the enhanced US examinations was inconclusive; the cost-efficacy ratio was $422 and $343 per successful diagnosis, respectively. Further management costs for patients with an inconclusive diagnosis were estimated at $6370 after the usual diagnostic tests, but only $1278 with enhanced US. Although the costs of the planned and recommended management pathways were similar ($227 and $294 per patient respectively), the proportion of patients requiring further resources was lower with enhanced US (56% v. 46%). Three-month actual management costs ranged from $121 to $1605 per patient (mean $360). Diagnostic tests and surgical procedures were the major cost drivers in all pathways, and costs were highest for patients in whom stenosis was diagnosed.

Conclusions: For patients with suspected renal artery stenosis, contrast-enhanced US had a higher diagnostic success rate than usual diagnostic methods and afforded savings through lower administrative costs and lower medical resource consumption for patients whose diagnosis was unclear after usual diagnostic tests.