1. A method of analyzing a quality control (QC) strategy for an instrument used to measure an analyte in patient biological samples, the method comprising: obtaining, by a computer system, a non-failure probability of error P E (0) of the instrument for the analyte and an average number of patient results reported between failures (MPBF) of the instrument; obtaining, by the computer system, information of the QC strategy, including: an interval between QC events that monitor the instrument using a reference sample; and a number of reference samples tested at each quality control event; calculating, by the computer system, an expected number of unreliable final results E(N uf ) for the QC strategy; obtaining, by the computer system, a probability P h|u that an unreliable final result leads to patient harm; computing, by the computer system, a proportion of patient results that are incorrect due to a failure of the instrument, the proportion including E(N uf ) divided by MPBF; computing, by the computer system, a combined probability of incorrect results by adding P E (0) and the proportion; computing, by the computer system, a predicted probability of harm by multiplying the combined probability and the probability P h|u ; outputting, by the computer system, an assessment of the predicted probability of harm compared to an acceptable probability of harm, wherein the acceptable probability of harm is dependent on a severity of harm resulting from an incorrect result; in response to the assessment indicating that the predicted probability of harm is lower or greater than the acceptable probability of harm, modifying the QC strategy by modifying the interval between QC events, the number of reference samples tested at each QC event, or both; and conducting the QC events on the instrument according to the modified QC strategy.