A new graphic means of displaying antibody data may offer advantages over current graphic displays. None of the current display techniques adequately display data on antibody levels when the results do not distribute into a normal bell-shaped curve. This proposed technique plots increasing antibody level on the horizontal axis and percentage of individuals with at least that level of antibody on the vertical axis on a scale of 0% to 100%. The shape of the curve, its slope, and where the curve lies with respect to the horizontal axis will tell the researcher how values are distributed among the population. Data from a study comparing antibody response to different pertussis vaccines are used to show how this way of plotting data makes detailed comparisons between vaccines easy.

Abstract:

Serologic data often have a wide range and commonly do not approximate a normal distribution. Means, medians, SDs, or other conventional numerical summaries of antibody data may not adequately or fully describe these complex data. The reverse cumulative distribution plot is a graphic tool that completely displays all the data, allows a rapid visual assessment of important details of the distribution, and simplifies comparison of distributions. Pediatrics 1995; 96: 600-603; antibody, cumulative distribution curve, plot, vaccine.