What condition is primarily assessed using the ankle-brachial index (ABI) test?

The ankle-brachial index (ABI) is a simple, non-invasive test used primarily to assess for peripheral arterial disease (PAD). This condition occurs when there is a narrowing or blockage of the arteries that supply blood to the legs, often due to atherosclerosis. The ABI test compares the blood pressure in the patient's ankle with the blood pressure in the arm. A lower ABI indicates reduced blood flow to the legs, which is characteristic of PAD.

The ABI is a reliable indicator of arterial health and is used both for diagnosis and to help determine the severity of PAD. In patients with suspected PAD, an ABI value of less than 0.90 typically suggests significant arterial occlusion and increased risk for cardiovascular events.

While other conditions are important in nursing practice, they do not involve the same assessment of blood flow and pressure comparison between the limbs as done in the ABI test. Venous insufficiency, for example, pertains to the function of veins and is assessed through different methods. Osteoarthritis and rheumatoid arthritis are both joint conditions that do not directly relate to arterial health or the assessment provided by the ABI.