Methods for measuring a cardiovascular parameter in a subject regardless of whether the subject is experiencing normal hemodynamic or abnormal hemodynamic conditions are described. These methods involve the determination of whether a subject is experiencing normal hemodynamic conditions or abnormal hemodynamic conditions, then applying an appropriate model to subject data to determine a cardiovascular parameter for the subject. Multivariate Boolean models are used to establish if the subject is experiencing normal hemodynamic or abnormal hemodynamic conditions, then multivariate statistical models are used to calculate the appropriate cardiovascular parameter. Having correct cardiovascular parameters for a subject experiencing abnormal hemodynamic conditions, for example, enables the calculation of accurate values for treatment relevant parameters, such as, cardiac output and stroke volume.