We appreciate the interest shown in our study by Scarlata and colleagues.1 We agree with them that, in line with several previous reports,2 3 the prevalence of the restrictive spirometric pattern was strikingly similar in the TESAOD4 and SARA5 studies, despite the substantial difference in age distribution between the two populations (the TESAOD report included subjects ≥21 years and the SARA study subjects ≥65 years of age).

However, a direct comparison of cause-specific mortality between the two studies should be interpreted with caution because of the different assessment of the restrictive spirometric pattern, which was evaluated at a single point in …