Method for reliable measurement in medical care and patient self monitoring

A method for assessing a person's response to a health intervention used to manage and treat a condition of the person, the method comprising the following steps:

• identifying at least one outcome measure indicative of whether an individual patient's response to the health intervention meets an aim of treatment defined by a predetermined magnitude of change or lack thereof in the outcome measure;
• defining an error component of the at least one outcome measure by performing at least one of the following to create a standard error of measurement:
• (i) estimating error in the outcome measure by performing a test-retest of the outcome measure on a plurality of subjects and generating test-retest data on the outcome measure therefrom, generating a reliability statistic and standard deviation from the test-retest data, and calculating the standard error of measurement based on the reliability statistic and standard deviation;
• (ii) estimating the error in the outcome measure by performing a test-retest of the outcome measure on a single subject and generating test-retest data on the outcome measure therefrom, generating from the test-retest data at least one of a standard deviation and a standard deviation adjusted for sample size, wherein the standard error of measurement is at least one of the standard deviation and the standard deviation adjusted for sample size;
• selecting a criteria of statistical significance and a multiplier corresponding to the selected criteria of statistical significance;
• generating an error component by multiplying the standard error of measurement by the multiplier to thereby ensure that any measurement with an outcome measure when the measurement falls outside of the error component will occur by chance with an average frequency not greater than the chance frequency defined with the criteria of statistical significance;
• and
• using the error component to select the frequency of administration and summary statistic of the outcome measure in a manner that facilitates achieving the aim of treatment.