Figure 3:

Adjusted incidence rate ratios (aIRR) for the association between heart rate recovery (HRR) and rate of (a) any acute respiratory events and (b) severe acute respiratory events (requiring emergency department visit or hospitalization). Results are presented for all participants (Total), and by spirometry subgroup. Incidence ratio ratios are adjusted for age, sex, race, body mass index (BMI), FEV₁ percent predicted, current vs former smoking status, and 6-minute walk test distance. aIRRs represent the change in rate for each 5 beat/minute change in HRR.

COPD, chronic obstructive pulmonary disease; PRISm, preserved ratio, impaired spirometry.