A z-score is a way of placing the measurement of a particular person (for example, a person’s body mass index [BMI], a marker of body weight) in the context of what that measurement is for other people in the population. It relies on knowing what the average (or “mean”) is for the whole population and the variability (how frequently and how much people are different from average, measured in terms of standard deviation). Technically, a z-score is the number of standard deviations from the mean a particular value is. A z-score=0 for a given individual indicates the value for that individual is equal to the mean of the population. A z=2 means that the value is 2 standard deviations above the mean of the population, meaning much “above average”. There are corresponding percentiles that are meaningful: a z=0 is equivalent to the 50th percentile, again indicating that 50 percent of the population has lower MetS severity than the individual. A z=2 is equivalent to the 97.7th percentile, indicating that 97.7% of the population has a lower MetS severity than the individual. Z-scores can be negative as well; z=-2 is the 2.28th percentile, meaning only roughly 2% of the population has a lower MetS severity.
A z-score is a way of placing the measurement of a particular person (for example, a person’s body mass index [BMI], a marker of body weight) in the context of what that measurement is for other people in the population. It relies on knowing what the average (or “mean”) is for the whole population and the variability (how frequently and how much people are different from average, measured in terms of standard deviation). Technically, a z-score is the number of standard deviations from the mean a particular value is. A z-score=0 for a given individual indicates the value for that individual is equal to the mean of the population. A z=2 means that the value is 2 standard deviations above the mean of the population, meaning much “above average”. There are corresponding percentiles that are meaningful: a z=0 is equivalent to the 50th percentile, again indicating that 50 percent of the population has lower MetS severity than the individual. A z=2 is equivalent to the 97.7th percentile, indicating that 97.7% of the population has a lower MetS severity than the individual. Z-scores can be negative as well; z=-2 is the 2.28th percentile, meaning only roughly 2% of the population has a lower MetS severity.
正在翻譯中..