Fig. (8) Expiratory Flow Limitation (% EFL) Data for Patients with Obesity Alone, Obstructive Sleep Apnea (OSA, mild-moderate, severe), COPD, and Control Subjects. Each notched box represents the 25th-75th percentile; internal line indicates the median; whiskers indicate the 10th and 90th percentiles. Notches extend to +/-1.58 inter-quartile range/sqrt (sample size). Notches that do not overlap suggest strong evidence of different medians. The general linear model used to model the ranks of the test variable as a function of the sitting and supine groups, adjusted for age and sex, showed significant differences amongst cohorts in the sitting posture, P=0.05, and amongst cohorts in the supine posture, P=0.005. ** Wilcoxon signed rank test (non-parametric paired-sample t-test) for comparisons between sitting and supine positions in each cohort.