This is a protocol for a Cochrane Review (Diagnostic test accuracy). The objectives are as follows:
To estimate the diagnostic accuracy of the ankle brachial index (ABI) - also known as the ankle brachial pressure index (ABPI) - for the diagnosis of peripheral arterial disease in people who experience pain on walking that is alleviated by rest (intermittent claudication).
We will also investigate the effect of sources of heterogeneity on diagnostic accuracy; specifically, the study setting, previous tests, types of equipment used, type of reference standard, different groups of patients (people with type I or type II diabetes and suspected aortic iliac disease), and the duration of symptoms by including them as covariates in the meta-analysis, if there are sufficient studies with relevant data. Other potential sources of heterogeneity will be examined graphically for signs that they are a cause of heterogeneity.