Accuracy of assessment instruments for patients' competence to consent to medical treatment or research

This is the protocol for a review and there is no abstract. The objectives are as follows: To assess the reliability and validity of the index tests for competence assessment versus the reference standard in people of any age. Although a gold standard for competence does not exist and the reference standard may be imperfect, we will examine whether using a structured assessment instrument instead of an expert judgement would be possible without compromising accuracy. To examine the accuracy of standardised competence assessment instruments in the subpopulation of patients under 18 years of age, with deficits in competence due to developmental stage.