3.3. The effects of asthma-related respiratory comorbidities on
mortality in the asthma cohort compared with the control cohort
As shown in Table 2 , the relative risk of mortality in
asthmatic patients without COPD (adjusted HR, aHR = 0.95, 95% CI =
0.90–1.01) or pneumonia (aHR = 0.98, 95% CI = 0.98–1.09) compared
with the controls was not significantly increased; however, asthmatic
patients with COPD (aHR = 1.49, 95% CI = 1.39–1.59) or pneumonia (aHR
= 1.59, 95% CI = 1.46–1.74) had increased risk of mortality compared
with the controls (aHR = 1.49, 95% CI = 1.39–1.59), which is in
agreement with survival analyses (COPD in Figure 3A and
pneumonia in Figure 3B) .
Regardless of the presence or absence of bronchiectasis or lung cancer,
asthmatic patients had an increased risk of mortality compared with the
controls. The presence of bronchiectasis (aHR = 1.43, 95% CI =
1.18–1.73) or lung cancer (aHR = 4.11, 95% CI = 2.59–6.52) tended to
further increase the risk of all-cause mortality in the asthmatic cohort
compared with the control cohort (bronchiectasis in Figure 3C
and lung cancer in Figure 3D ). Although the risk of mortality was
increased in asthmatic patients without NTM infection (aHR = 1.13, 95%
CI = 1.08–1.18) compared with subjects without asthma, there was no
significant increased risk of mortality in asthmatic patients without
NTM infection compared with subjects without asthma (aHR = 0.85, 95% CI
= 0.12–6.00; Figure 3E ).
Except for lung cancer, patients in the asthma cohort had a higher risk
of respiratory mortality compared with subjects in the control cohort
regardless of respiratory comorbidities. The presence of these
respiratory comorbidities tended to further increase the risk of
respiratory mortality in the asthmatic cohort compared with the control
cohort (Table 2 ).