Background Standards for clinical practice enacted by external accreditation organisations can limit the ability of health care organisations to develop and implement evidence-based guidance to improve clinical practice and health system efficiency, and reduce unnecessary testing.

Context As part of a system-wide effort to improve patient quality and access, medical specialists in a large group practice sought to determine whether standard bilateral venous duplex ultrasound (VDUS) scans were medically necessary in patients with unilateral signs and symptoms of deep vein thrombosis (DVT). Typically these patients receive bilateral exams; however, the high number of negative test results in non-symptomatic legs suggested bilateral testing may not be necessary.

Description of Best Practice An evidence review was conducted to evaluate whether unilateral VDUS scanning accurately identifies patients who can safely undergo unilateral VDUS exams in the symptomatic limb without missing a DVT in the unscanned, asymptomatic limb. The evidence review concluded that the number of undetected DVTs in the unscreened asymptomatic limb was very low, suggesting that unilateral VDUS screening in lower-risk patients (i.e., outpatients and patients without malignancy) could be safely performed. Accreditation standards, however, require bilateral screening in all patients, regardless of DVT risk status.

Lessons for Guideline Developers, Adaptors, Implementers, and/or Users Accreditation standards can hinder practice change and limit research for more effective and efficient practices. Some accrediting organisations accept feedback and adjust standards as new data emerges. Providing evidence-based information to these organisations may initiate changes in standards.