1. A system to calibrate a glucose sensor, comprising: a glucose sensor monitor associated with the glucose sensor having a memory for storing program instructions and a plurality of measured glucose concentrations, the stored measured glucose concentrations received from the glucose sensor, a processor being integrated into the glucose sensor monitor, the processor executing the stored program instructions to determine a rate of change of measured blood glucose concentration and a calibration factor the calibration factor being based on a calibration reference value, a temporally correlated data value, the temporally correlated data value being selected from the plurality of measured glucose concentrations and further being determined by correlating one of the measured glucose concentrations to a threshold parameter such that a first time delay is used if the glucose concentration is less than the threshold parameter and a second time delay is used if the glucose concentration is equal to or exceeds the threshold parameter, and if the rate of change of measured blood glucose concentration exceeds a threshold limit, a predetermined multiplier is applied to the calibration factor, wherein the calibration factor is stored in the memory, the calibration factor further being used to convert the plurality of measured glucose concentrations to a plurality of calculated glucose concentrations.