Longitudinal repeated measures data has often been visualized with spaghetti plots for continuous out- comes. For large datasets, this often leads to over-plotting and consequential obscuring of trends in the data. This is primarily due to overlapping of trajectories. Here, we suggest a framework called lasagna plot ting that constrains the subject-speciﬁc trajectories to prevent overlapping and utilizes gradients of color to depict the outcome. Dynamic sorting and visualization is demonstrated as an exploratory data analysis tool. Supplemental material in the form of sample R code additional illustrated examples are available online.
Longitudinal Data Analysis and Time Series
Swihart, Bruce; Caffo, Brian ; James, Bryan D.; Strand, Matthew; Schwartz, Brian S.; and Punjabi, Naresh M., "LASAGNA PLOTS: A SAUCY ALTERNATIVE TO SPAGHETTI PLOTS" (October 2009). Johns Hopkins University, Dept. of Biostatistics Working Papers. Working Paper 141.