title: Temporal changes in the concentrations of serum constituents in healthy men. Distributions of within-person variances and their relevance to the interpretation of differences between successive measurements.
abstract: The distributions of within-person variances in the concentrations of 10 commonly assayed serum constituents have been derived from data on 37 healthy male subjects studied at weekly intervals over a period of five months. All 10 distributions appear to be of log-normal form. The relevance of the findings to the interpretation of differences between serial measurements in a given individual is discussed. Examples are given to show how the information on within-person variances for a particular analyte, organised into a simple graph, may be used to test medical opinions on threshold values for serial changes in the concentration of this analyte in a given individual. In this way, biological variability as well as analytical error may be taken into account quantitatively when assessing the significance of a difference between two serial measurements.
mesh_terms: D000328:Adult; D000469:Alkaline Phosphatase / Q000097:blood; D001663:Bilirubin / Q000097:blood; D001769:Blood / Q000378:metabolism*; D001774:Blood Chemical Analysis; D001798:Blood Proteins / Q000378:metabolism; D002118:Calcium / Q000097:blood; D003404:Creatinine / Q000097:blood; D006801:Humans; D008297:Male; D008875:Middle Aged; D010710:Phosphates / Q000097:blood; D011188:Potassium / Q000097:blood; D012709:Serum Albumin / Q000378:metabolism; D012964:Sodium / Q000097:blood; D013223:Statistics as Topic; D014508:Urea / Q000097:blood
chemical_list: D001798:Blood Proteins; D010710:Phosphates; D012709:Serum Albumin; D014508:Urea; D012964:Sodium; D003404:Creatinine; D000469:Alkaline Phosphatase; D001663:Bilirubin; D011188:Potassium; D002118:Calcium