A method for determining risk of an adverse event, such as thrombosis or a required intervention, associated with a vascular access includes receiving hemodialysis treatment data associated with the vascular access, deriving a plurality of selected risk factors from the hemodialysis treatment data, evaluating the plurality of selected risk factors over a time period, assigning raw scores to each selected risk factor based on its values over the time period, summing the raw scores for the plurality of selected risk factors to determine a cumulative raw score, and correlating the cumulative raw score with a level of risk of an adverse event associated with the vascular access.