Kaplan-Meier Estimates of Age until Cessation of Work Activities, by Disease Group. Note: Solid line represents group with no chronic conditions; broken line represents the specified disease group. All conditions differ from group with no conditions (p < 0.05 by Wilcoxon Test). COPD differs from rhinitis group (p < 0.05 by Wilcoxon Test).
Yelin et al. Journal of Occupational Medicine and Toxicology 2006 1:2 doi:10.1186/1745-6673-1-2