1. A method performed by a computer of evaluating coded medical documents, the method comprising: receiving, by a computer, audit parameters comprising an expected coder error level, and receiving an empirically established expected auditor error level of an auditor based on an assessment of the auditor; selecting, by the computer, a sample batch of coded medical documents for auditing by the auditor, the sample batch of coded medical documents selected from a universe of coded medical documents stored on one or more storage devices, the selection based at least in part on the received audit parameters; receiving, by the computer, audited medical documents corresponding to the selected sample batch of coded medical documents, wherein the audited medical documents include corrections by the auditor; calculating, by the computer, a medical document score for each of the audited medical documents based on medical document corrections received from the auditor and applying weighted factors, wherein the weighted factors comprise predefined weights assigned to diagnosis and procedure codes in each of the audited medical documents; calculating, by the computer, a sample score for the audited medical documents based on a function of the calculated medical document scores; designating, by the computer, at least one of an upper control limit and a lower control limit based on the expected auditor error level; and comparing, by the computer, the sample score against the at least one of the upper and lower control limits to determine an acceptability of the sample score.