understanding laboratory tests - lecture notes - julia

Question 1

what are reference intervals?

Answer 1

normal range
interval of values that encompasses 95% of the “normal” population
so if gaussian range of values, central 95th percentile

Question 2

how are reference intervals determined if the data is skewed (meaning there’s a positively or negatively skewed distribution to the normal curve)

Answer 2

• can try to normalize a set of data that is not normal with a transformation
• can use a nonparametric method - order data set from low to high and calculate the upper and lower 2.5%