Fig. 4

Kaplan–Meier plot for all-cause mortality. Kaplan–Meier plot of time to all-cause mortality (one line for each cluster and one line for the respiratory asymptomatic subjects, with shaded area around the line denoting the 95% confidence interval). At the bottom are the number of subjects at risk at 0, 5, 10, 15, and 20 years post-baseline (defined as the start of the year of questionnaire distribution) in each cluster (and in the respiratory asymptomatic subjects)