Fig. 2. Labor progress data.  Small vertical lines are data points, and  gray lines are individual fits. (  A ) Initial model without covariates,  solid black line represents the typical individual,  thick gray line represents a supersmoother through the data, and the  dashed line is a supersmoother through the  post hoc estimates. (  B ) Final model incorporating covariate effects,  thick gray line represents a supersmoother through the data, and the  dashed line is a supersmoother through the  post hoc estimates. (  C and  D ) Individual measured-predicted observations over time for the initial and final modals are  thin gray lines . The  dashed line is a supersmoother through the data. Asian ethnicity, presence of neuraxial analgesia, and maternal weight were included as covariates in the final model. All data points are represented in the initial model. The final model excludes patients in whom weight was not recorded (n = 98 excluded) .